Planet Earth Spring 2012

www.planetearth.nerc.ac.uk

Spring 2012

The

smoke detectors

Snakebite! • Human language diversity • Spotting ice from space • Radar • Shale gas

About NERC The Natural Environment Research Council (NERC) is the UK’s main agency for funding research, training and knowledge exchange in environmental science. Our work tackles some of the most urgent and fascinating environmental issues we face, including climate change, natural hazards and sustainability.

NERC is a non-departmental public body. Much of our funding comes from the Department for Business, Innovation and Skills but we work independently of government. Our projects range from ‘blue-skies’ research to long-term, multi million pound strategic programmes, coordinated by universities and our own research centres:

NERC research covers the globe, from the deepest ocean trenches to the outer atmosphere, and our scientists work on everything from plankton to glaciers, volcanoes and air pollution – often alongside other UK and international researchers, policy-makers and businesses.

British Antarctic Survey British Geological Survey Centre for Ecology & Hydrology National Oceanography Centre National Centre for Atmospheric Science National Centre for Earth Observation

Editors Adele Rackley, 01793 411604 admp@nerc.ac.uk Tom Marshall, 01793 442593 thrs@nerc.ac.uk

Planet Earth is NERC’s quarterly magazine, aimed at anyone interested in environmental science. It covers all aspects of NERC-funded work and most of the features are written by the researchers themselves.

Science writer Tamera Jones, 01793 411561 tane@nerc.ac.uk Design and production Candy Sorrell, 01793 411518 cmso@nerc.ac.uk Print Gemini Press on 9 Lives 55 Silk, an FSC-accredited recycled paper.

Contact us For NERC-funded researchers contact: editors@nerc.ac.uk To give us your feedback email: requests@nerc.ac.uk or write to us at Planet Earth Editors, NERC, Polaris House, North Star Avenue, Swindon SN2 1EU.

Front cover: Forest fire - Shaun Lowe/istockphoto.com

For the latest environmental science news, features, blogs and the fortnightly Planet Earth Podcast, visit our website Planet Earth Online at www.planetearth.nerc.ac.uk.

Not all of the work described in Planet Earth has been peer-reviewed. The views expressed are those of individual authors and not necessarily shared by NERC. We welcome readers’ feedback on any aspect of the magazine or website and are happy to hear from NERC-funded scientists who want to write for Planet Earth. Please bear in mind that we rarely accept unsolicited articles, so contact the editors first to discuss your ideas.

ISSN: 1479-2605

In this issue Spring 2012

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FEATURES 8 Snakebite!

Venom research could save thousands of lives.

10 Forked tongues

How did we end up with so many languages?

12 The smoke detectors

Flying over forest fires to learn about the air pollution they cause.

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14 Somewhere over the radar

How a facility in the Arctic Circle is probing the mysteries of space weather.

16 Eyes in the sky

Eight uses for satellites in environmental science.

17 Data for all

Storing and sharing a priceless asset.

18 Not just a pile of old dung

What bat guano can tell us about ancient biodiversity.

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20 Shale: no great shakes?

The real low-down on a new energy source.

22 Spotting ice from space

The next generation of polar science.

24 Tasting the salt of the Earth’s oceans

Satellites are giving us a new global view of how salt and fresh water are distributed.

26 We’re all in it together

Sharing knowledge to make the most of UK peatlands.

PODCAST Q&A 28 The Antarctic ozone hole: 25 years on

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Richard Hollingham interviews the British Antarctic Survey’s Jonathan Shanklin.

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News Editorial C

hristmas wasn’t quite over when we came back to work this new year, because our inbox was full of readers’ emails and letters about the winter edition of Planet Earth.

Thanks to everyone who got in touch, and we’re pleased you found the mix of news and features as interesting as ever.

We are also very pleased to welcome our new chief executive, Professor Duncan Wingham, formerly director of NERC’s Centre for Polar Observation and Modelling, who joined us on 1 January.

This spring we’ve put together a range of subjects as diverse as forest fires and the evolution of human languages. Two features look at different aspects of earth observation from space, so we’ve thrown in a few extra things you might not know about the many ways satellites are used in environmental science.

For animal lovers, we’ve included snakes and bats in this edition. Find out how a new collaboration of physicians, scientists and anti-venom manufacturers is improving the lot of snakebite victims around the world. Meanwhile other researchers have been braving the depths of guano deposits from millions of cave-roosting bats, to unlock the secrets of biodiversity and past environments in south-east Asia.

As ever, tell us what you like or don’t like, or if you prefer to read Planet Earth online rather than on paper, get in touch and let us know. Contact details are on the inside front cover.

The Editors

Targeting pollution could save millions of lives L imiting how much soot and methane reach the atmosphere using existing technologies could save nearly five million lives a year, and vastly boost global crop yields, scientists report. It could also slow global warming by around half a degree by 2050.

‘Measures to control methane and black carbon emissions would have multiple, large benefits to global and regional climate, human health and agriculture,’ write the authors of the Science report.

The findings suggest that all countries would benefit from less soot and methane in the atmosphere. But the biggest effects would be felt in central and northern Asia, southern Africa and the Mediterranean. The researchers estimate that between 700,000 and 4.7 million premature deaths could be prevented in Africa and Asia.

Crop yields in China, India, the US, Pakistan and Brazil could increase by between 30

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million and 135 million tonnes a year.

An international team of researchers led

by Drew Shindell from NASA’s Goddard Institute for Space Studies used sophisticated emissions, air-quality and climate models to estimate the potential benefits of emissions reductions.

After screening around 400 different emissions-control measures, they identified 14 strategies that rely on current technologies, and – if implemented immediately – would slow global warming. Half target soot emissions, and half methane. All have been shown to work in practice.

‘All 14 measures are based on existing technologies and can be implemented immediately, so do not require long development processes. The measures maximise climate benefits but would also have important ‘win-win’ benefits for human health and agriculture,’ says co-author Dr Johan Kuylenstierna from the University of York.

Ways to cut methane emissions include capturing gas that would normally escape from coal mines and oil rigs, reducing leaks from long-distance gas pipelines, and limiting emissions from manure on farms. Anti-soot measures include installing particle filters on diesel vehicles, keeping high-emitting vehicles off the road, and banning the burning of farm waste.

Daily updated news @ www.planetearth.nerc.ac.uk

The Hoff sighted in Antarctic waters New climate-cooling molecule found S S cientists have discovered many new marine species clustered in the hot, dark environment around hydrothermal vents on the deep-sea floor near Antarctica.

They include a new species of crab, an unidentified octopus, an undescribed sevenarmed sea-star, starfish, barnacles, limpets and sea anemones.

Yeti crabs are so called because they look unusually hairy. They use the hairs on their limbs as a breeding ground for tasty bacteria.

But the Antarctic yeti crabs are a completely new species, with hairs on their undersides.

The researchers dubbed them The Hoff, in honour of the hirsute Baywatch star.

The UK-led team made its discovery after exploring the East Scotia Ridge on the seabed off the coast of South Georgia in the Southern Ocean, using a remotely-operated vehicle called Isis. The ridge, around 2500 metres deep, is dotted with hydrothermal vents where geothermally-heated water – up to 382°C –

forces its way to the surface through fissures in the sea floor.

‘Hydrothermal vents are home to animals found nowhere else on the planet that get their energy not from the sun, but from breaking down chemicals such as hydrogen sulphide,’ says Professor Alex Rogers from Oxford University, who led the research. ‘The first survey of these particular vents, in the Southern Ocean near Antarctica, has revealed a hot, dark ‘lost world’ in which whole communities of previously unknown marine organisms thrive.’

‘These findings are yet more evidence of the precious diversity to be found throughout the world’s oceans,’ he adds. ‘Everywhere we look, whether it’s the sunlit coral reefs of tropical waters or these Antarctic vents shrouded in eternal darkness, we find unique ecosystems that we need to understand and protect.’

The discoveries were made as part of a consortium project with partners from the University of Oxford, University of Southampton, University of Bristol, Newcastle University, British Antarctic Survey, National Oceanography Centre and Woods Hole Oceanographic Institution.

The study is published in PLoS Biology.

cientists have detected a new atmospheric molecule, whose existence has long been suspected but never proved.

So-called Criegee biradicals were implicated in several vital atmospheric processes – links in the complex cascades of reactions by which one chemical is processed into another. Their existence was incorporated into models of how pollutants like nitrogen and sulphur dioxide are turned into nitrates and sulphates; this means they play an important role in controlling the climate.

But this is the first time the molecules have been observed directly, using custom-designed instruments and a special kind of ultra-intense light produced by powerful particle accelerators. Known as synchrotrons, these let researchers observe the basic structure of molecules in incredible detail as it changes over tiny intervals.

‘We’ve known for a long time that Criegee biradicals are involved in several important reactions in atmospheric chemistry, but nobody’s been able to observe them directly until now,’ says Dr Carl Percival of the University of Manchester, one of the report’s authors.

The biradicals turn out to play an important role in removing pollutants from the atmosphere. For example, erupting volcanoes blast large volumes of sulphur dioxide into the atmosphere. Scientists have long known this has a cooling effect, as the sulphur dioxide is turned into sulphates and eventually into sulphuric acid, which causes clouds to form. The new findings demonstrate a previously-unknown mechanism by which this transformation can take place.

‘This new source of atmospheric sulphates is at least as important as the one we knew about already, and in some cases it can dominate,’ Percival explains.

Climate models will probably need to be updated to take the discovery into account.

The breakthrough, published in Science, was made by researchers at the universities of Bristol and Manchester and at Sandia National Laboratories.

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News Wolves help predict climate-change effects S The researchers then used the data to generate a powerful computer model to get a glimpse of the wolves’ responses to a changing environment.

Previous studies on other animals, such as Soay sheep and polar bears, have demonstrated that different biological traits can affect species’ future population size.

Even small changes in traits like body size and weight, coat colour, when they first reproduce, and how long they live, all have an effect, as long as they persist over a long enough period of time.

For example, in contrast to European wolves, whether or not Yellowstone wolves have a grey or black coat depends on how much forest cover features in their environment.

Grey wolves were reintroduced to Yellowstone in 1995, after having been driven to extinction by settlers earlier in the century. Since their reintroduction, their numbers have exploded. Now there are around 150 wolves in the park.

Ken Canning/istockphoto.com

cientists have used a detailed study of grey wolves in Yellowstone National Park to develop a way to predict how climate change could affect a range of creatures over the coming years.

The findings, published in Science, could ultimately help conservationists figure out which animals will be resistant to environmental change, and which ones could be at risk of extinction.

‘This work provides a relatively easy way for biologists to investigate how, and why, environmental change impacts both the ecology and near-term evolutionary future of species,’ says Professor Tim Coulson from Imperial College London, who led the study.

Coulson and colleagues from the universities of Minnesota and California, and Yellowstone National Park, analysed data taken from grey wolves over 15 years. The data they used included information about population numbers, genetics and body size, and was gathered during good years, when the wolves thrived, as well as bad years when they didn’t do so well.

Darwin’s lost fossils A

rare collection of fossils, including some collected by Charles Darwin, has been rediscovered at the British Geological Survey (BGS).

The fossils, lost for 165 years, have now been photographed and are available to the public through a new online museum exhibit at http://bit.ly/xbR9lL. Dr Howard Falcon-Lang, a palaeontologist at Royal Holloway, University of London, was in the BGS archive looking for fossil-wood specimens when he made the discovery.

‘I spotted some drawers marked “unregistered fossil plants”,’ he recalls. ‘I can’t resist a mystery, so I pulled one open. What I found inside made my jaw drop!’ Inside were hundreds of fossil plants, polished into translucent sheets known as ‘thin sections’ and captured in glass slides so they could be studied under a microscope.

His jaw dropped even further when he started taking out the slides. One of the first

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was labelled ‘C. Darwin Esq.’ ‘This turned out to be a piece of fossil wood collected

by Darwin during his famous voyage on the Beagle in 1834,’ he says, ‘the expedition on which Darwin first began to develop his theory of evolution.’

It turns out that botanist Joseph Hooker, longtime director of Kew Gardens and Darwin’s best friend, assembled the collection during a brief stint at BGS in 1846. Among the specimens were some found by Hooker himself during an Antarctic voyage in 1840. Others

seem to have come from the cabinet of the Reverend John Henslow, Darwin’s mentor at Cambridge, whose daughter later married Hooker.

The collection shows how wide a net British scientists had already cast in the early 19th century. As well as items from well-known British fossil sites, like the Isle of Portland in Dorset, it includes fossil wood from the Caribbean, Australia, Egypt, India and the Far East.

This spectacular slide shows the crosssection of a cone of a monkey-puzzle tree.

Daily updated news @ www.planetearth.nerc.ac.uk

Three-quarters of UK butterflies in decline early three-quarters of the UK’s butterflies have declined over the last ten years, according to a summary of two major UK-led citizen science projects. The report also found that the distributions of more than half of the insects have shrunk.

According to the study, collated by Butterfly Conservation and the Centre for Ecology & Hydrology, butterflies that have specific habitat requirements, such as the high brown fritillary and the Duke of Burgundy, have fared particularly badly.

The researchers say ongoing deterioration of habitats is the main reason for the insects’ decline. Butterflies such as the pearlbordered fritillary need open sunny glades in woodlands, a habitat produced by traditional woodland management rarely employed in the vast majority of UK woodlands these days.

Over the ten-year study period, the researchers found that the high brown fritillary saw its numbers drop by 69 per cent, while Duke of Burgundy numbers fell by 46 per cent. Even some of the more common species, like the small skipper, the small tortoiseshell and the common blue, have declined by almost a quarter.

‘Species that need specialised habitats are generally doing quite badly,’ says Dr Marc

Botham, a butterfly ecologist from the Centre for Ecology & Hydrology, co-author of the report. ‘It’s clearly quite worrying.’

‘UK butterflies are still in serious decline and remain one of our most threatened wildlife groups in spite of increased conservation expenditure,’ write the authors in the report.

But it’s not all bad news. The study found that 31 species showed some evidence of increase in either their distribution or population trend. There are also promising signs that species that have been in decline over the last few decades have bounced back.

‘In these examples, it’s because the sites have been managed well, so the butterflies have responded positively,’ says Botham.

‘The large blue is a good example of such a success.’

This butterfly was reintroduced in the UK after going extinct in the 1970s. The key to this success story was a detailed understanding of what the insect needs to be able to survive and flourish.

‘We hope to be able to apply the techniques used in these success stories to other species,’ Botham says.

Large blu

Three images: Jim Asher, Butterfly Conservation

N

Small skipper.

High brown fritillary.

e.

Duke of Burgundy.

Keith War mington , Butterfl y Conse rvation

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News Downturn doesn’t keep emissions down for long

Panamanian

golden frog.

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Brian Gratwicke/Wikimedia

lobal carbon dioxide emissions from burning fossil fuels increased 49 per cent in the last two decades, new figures show. And the growth has rebounded sharply from a short-lived drop caused by the economic downturn.

Published in Nature Climate Change, the Global Carbon Project analysis shows emissions grew 5.9 per cent in 2010, and were projected to increase by another 3.1 per cent in 2011.

‘Many saw the global financial crisis as an opportunity to move the global economy away from persistent and high emissions growth, but the return to emissions growth in 2010 suggests the opportunity was not exploited,’ says lead author Dr Glen Peters of the Centre for International Climate and Environmental Research in Norway.

Total emissions, which include CO2 given off by other activities like cement production, changes in land use and deforestation, as well as from burning fossil fuels, reached 10 billion tonnes for the first time in 2010. Carbon concentration in the atmosphere reached 398.6 million parts per million.

Emissions fell during 2008-9 as the worldwide economy contracted, but growth resumed last year in both developed and developing economies. Rich countries continue to effectively outsource their carbon emissions by moving industrial and manufacturing activity to the developing world where environmental restrictions are less stringent.

The biggest contributions to 2010’s emissions growth were China, the US, India, Russia and the European Union. ‘Global CO2 emissions since 2000 are tracking the high end of the projections used by the Intergovernmental Panel on Climate Change, which far exceed two degrees of warming by 2100,’ says Professor Corrine Le Quéré of the University of East Anglia, director of the Tyndall Centre for Climate Change Research and co-author of the report.

Why are frogs croaking?

Blame the animal trade T

he global trade in frogs and other amphibians may have accidentally helped create and spread the deadly fungal disease, chytridiomycosis, devastating populations worldwide. Unless it’s regulated, even deadlier strains could emerge.

The fungus, sometimes called Batrachochytrium dendrobatidis (Bd), infects the skins of animals like frogs, toads and salamanders. An international team of scientists, led by Dr Matthew Fisher from Imperial College London, found the amphibian trade may have brought non-lethal Bd strains from different parts of the world into contact.

These varieties exchanged genes, creating a new and lethal strain which has devastated frog populations around the world.

More than 200 species are suspected to have died out as a result, and in Central America alone, Bd has caused the loss of up to 40 per cent of wild amphibians. But despite much research, scientists have struggled to understand where it came from or how it spread.

This is even more puzzling because some amphibians live alongside Bd with no sign of disease, suggesting there was more than

one type of fungus. So the team decided to sequence and compare genomes from 20 disease samples isolated from 11 amphibian species worldwide, to find out more about the fungus’s ancestry.

They found three different strains. One of these has made its way to at least five continents. It showed signs of gene exchange, and turned out to be the deadliest of the three. Finding so many strains in just 20 samples suggests Bd is more diverse than previously thought. ‘What’s interesting is that they’re not all causing disease,’ says Fisher.

‘Only one lineage is a killer, and it has evolved very recently’. Scientists previously thought there was just one strain.

The start of amphibians’ decline around the 1970s may have been no coincidence. ‘The age of the lethal BdGPL lineage coincides with the start of the amphibian trade in the 20th century, when we started moving many frogs and toads around the world,’ Fisher says. ‘The horse has well and truly bolted, but to halt the further spread of this disease we really need to increase global biosecurity.’

The research appears in Proceedings of the National Academy of Sciences.

Daily updated news @ www.planetearth.nerc.ac.uk

Mapping what lies beneath S

cientists have created a new highresolution 3D map of the bedrock deep beneath the Antarctic ice.

Pictured below, it gives a sense of how the vast landmass would look if its thick covering of ice were removed. Only a tiny fraction of this rock is normally visible above the icecap.

Led by British Antarctic Survey (BAS) researchers as part of the International Polar Year, the BEDMAP2 initiative builds on the work of a previous project carried out early in the last decade, adding much more detail based on data gathered using aircraft, satellites and ships.

‘With all this new data, what we can see emerging now is an actual landscape with recognisable mountains and valleys deep below the ice,’ says Dr Hamish Pritchard of BAS, who led the project.

BEDMAP1, released in 2001, incorporated 1.9 million measurements. Its sequel draws on more than 27 million, mapped onto a 5km grid. Among the new datasets incorporated

are improved information on ice-shelf thickness, surface topography and even the depth of coastal waters.

It’s a radical improvement on what went before and will benefit scientists in fields from seismology to ice-core interpretation and study of the Earth’s gravity and magnetic fields.

The map will help understand how ice moves across Antarctica. First formed in the continent’s interior as snow falls and becomes compacted, the ice flows – at first incredibly slowly and then with increasing speed – towards its edges and eventually enters the sea as icebergs. Scientists think climate change is accelerating this natural process in some areas, so that ice ends up in the water more quickly than before and contributes to sea-level rise.

The map is still being developed. Pritchard hopes to release the final version in late March.

in brief . . .

Research into bumblebee foraging could aid conservation UK researchers have found that exactly how far a bumblebee will fly to find food depends entirely on the structure of the landscape, including how much food is around.

The findings could be important for landscape managers looking to both protect bumblebee populations, and restore landscapes for these crucial pollinators.

Scientists from the Centre for Ecology & Hydrology, the University of East Anglia and the Zoological Society of London focused their studies on the red-tailed bumblebee and the common carder bee.

Engineers pave the way for Lake Ellsworth exploration A team of British engineers has returned to the UK after completing a gruelling journey to one of the most remote and hostile locations on the planet.

They put in place equipment and supplies for a team of researchers to explore an ancient lake buried beneath three kilometres of Antarctic ice.

In temperatures of -35°C, and using a powerful tractor-train, the Lake Ellsworth advance party towed nearly 70 tonnes of equipment to a site close to the subglacial lake. Later this year, researchers plan to collect water and sediment samples from the lake, which may have been hidden from the rest of life on Earth for up to a million years.

New face for Planet Earth Online Our science news website Planet Earth Online has had a facelift over the winter.

We’ve freshened up the home page, breathed new life into our blog and made it easier to browse the subjects you’re interested in. It’s also quicker to follow us and share content through social bookmarking.

Visit us online for the latest environmental science news and features, the fortnightly Planet Earth Podcast, and links to archive features and the e-magazine version of Planet Earth. www.planetearth.nerc.ac.uk

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FEATURE

Wolfgang Wüster

Local farmers wear poor or non-existent Saw-scaled viper. footwear while ploughing just yards from where the snakes live.

Snakebite!

Imagine you are manually ploughing a field in a tropical country; you feel a quick stabbing pain in your uncovered foot and notice a snake slithering away. Your foot is bleeding from two puncture wounds and is starting to swell. Before long you are in pain; your gums start bleeding, or perhaps you start struggling to breathe, or your foot turns black and needs amputating. It’s a horrific picture, but it’s all too real for many of the two million people bitten by venomous snakes every year. Nick Casewell’s team are working to find a solution.

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A

stonishingly, in some regions snakebite victims occupy over 70 per cent of all hospital beds, and as many as 95,000 people die each year, even though effective treatments exist.

Snakes are often viewed in a negative way.

Let’s face it, this isn’t particularly surprising, considering the social stigma attached ever since their time in the Garden of Eden or living on Medusa’s head. Yet in some cultures snakes are actually worshipped, and they appear in positive contexts on the emblems of medical and pharmacy associations, which may well have been an early and appropriate masterstroke – more on this later.

Snake venoms usually differ between different species, but all are toxic mixes of proteins that are injected (usually by fangs) to incapacitate the snake’s prey. Although most snakes are technically venomous, relatively few species are dangerous to man.

Snakes will try to avoid encounters with people or display a warning signal, such as a rattlesnake’s rattle, before they bite.

Unfortunately, when one feels threatened or is surprised by a person, it will often bite in self-defence, resulting in a medical emergency.

Sadly this is extremely common across the tropics. In the UK we only have one potentially dangerous snake species, which is rarely encountered. In sub-Saharan Africa and south Asia, where most snakebite deaths occur, there are many dangerous snakes, including cobras, mambas and vipers. In rural tropical regions, people’s lifestyle is dictated by poverty, so interacting with snakes is a daily occupational hazard when farming, walking or even sleeping. These encounters are often made worse because people cannot afford appropriate footwear and often work in flip-flops or even barefoot.

I recently had the opportunity to go to Senegal to collect venomous snakes for our antivenom research project – our target species were the saw-scaled vipers, a group of very small dangerous snakes which are extremely well camouflaged. We often found them hiding under rocks during the day – by the side of roads, around agricultural fields and even in school playgrounds. On one occasion I noticed a barefoot farmer

Both images: Wolfgang Wüster

knocking stones aside to allow him to till the earth not ten yards away from where we’d recently found a saw-scaled viper beneath a similar rock. It is not hard to imagine how people stand on these snakes and are bitten.

So what happens if you’re bitten by a venomous snake?

If you live in the developed world, you go to hospital and, if you need it, the doctors give you antivenom, which will usually save your life. Antivenoms are made by immunising animals with tiny (non-harmful) amounts of venom collected from snakes. After a while, the immune system of the animal produces ‘antibodies’ against the snake venom.

These immune proteins are collected and purified into antivenom. When this is injected into a patient, the antibodies work by finding the venom proteins and sticking to them, preventing them from causing harm. However, these antibodies work only on the venom that was used to produce them, so rattlesnake antivenom won’t work against a cobra bite.

In the tropics, the situation is less favourable for the victim – antivenom is expensive, often costing up to six months’

Left: A juvenile saw-scaled viper (with finger for scale) found underneath a rock.

Right: The author, with snake bag, among rocks where the snakes are typically found, very close to a village.

antivenom treatments and saved around 16,000 lives. However, these collaborations are rare because the financial incentives for antivenom manufacturers are low – their antivenoms are specific to certain snakes in certain regions and many governments and people simply can’t afford to buy them, which results in low demand.

As part of the antivenom research we are carrying out with scientists from Bangor University, we wanted to investigate how effective antivenom made for one species was at preventing damage caused by different snakes’ venom. Saw-scaled vipers,

I noticed a barefoot farmer, knocking stones aside to till the earth not ten yards away from where we’d recently found a saw-scaled viper . . .

salary. It may not be available, and even if it is, it may have taken the victim many hours, or even days, to reach a hospital – by this time the antivenom is less effective because the venom has already had a chance to damage the body. Together these problems mean snakebite is very much a disease of poor people in the rural tropics.

At the Alistair Reid Venom Research Unit at the Liverpool School of Tropical Medicine we are passionate about helping, by improving existing antivenoms and developing new treatments for snakebite.

For example, in collaboration with two antivenom-manufacturing companies, UK’s MicroPharm and ICP in Costa Rica, we have coordinated the development of two new, highly-effective and safe antivenoms that the Nigerian Ministry of Health is now buying for use in hospitals in parts of the country.

So far, this work has resulted in 32,000

comprising at least nine different species, kill more people worldwide than any other group, so we used them as the targets for our investigation.

After collecting venom from different varieties of saw-scaled viper living in various parts of Africa and Asia, we tested each venom in the laboratory against a single antivenom made from the venom of the West African lineage. We were delighted to find that this antivenom was just as effective against all African saw-scaled vipers, not just those from West Africa.

This is really important because it means we can now use the existing antivenom to treat saw-scaled viper bites in parts of Africa where antivenom is not currently used – this expanded geographical market will lead to economies of scale, where an increase in manufacturing means antivenom costs governments and people less, which in turn increases demand still further and improves

the delivery of antivenom to the patients.

This model is also being used by the Global Snakebite Initiative, a recently established consortium of physicians, scientists and antivenom manufacturers designed to improve medical care of, and delivery of life-saving antivenoms to, snakebite victims throughout the world.

Although the venoms of snakes and other animals can cause very serious harm to people, they are also a valuable natural biological resource. Venom proteins have been a fantastic starting point for the development of new pharmaceutical drugs and diagnostic tools. For example, the blood pressure medication captopril was developed from the venom of a South American viper and has been used to treat about 16 million people in the UK. Because of these early successes there is now a lot of interest in developing new drugs from the venoms of a variety of animals, including snakes, lizards, fish and spiders.

We are really interested in discovering how proteins found in the venoms of these animals work and whether they can be used in the treatment of human diseases. This exciting new line of research means that it’s starting to look like the medical and pharmacy associations may have been right to put the snake on their emblems all those years ago. n

More information Dr Nick Casewell is a postdoctoral research associate at the Alistair Reid Venom Research Unit, Liverpool School of Tropical Medicine. Email: n.r.casewell@liv.ac.uk. The antivenom research project is headed by Dr Robert Harrison at the Liverpool School of Tropical Medicine in collaboration with Dr Wolfgang Wüster at Bangor University.

Find out more about the Global Snakebite Initiative at www.snakebiteinitiative.org

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FEATURE

urosr / Shutterstock.com

Forked tongues:

the evolution of human languages Humans have the dubious distinction of being perhaps the only species whose members cannot all communicate with each other. Mark Pagel asks what’s behind this apparently unhelpful trait, and what the future might hold for the diversity of human language.

T

here are about 7000 distinct human languages spoken on Earth – that’s more languages for our single mammal species than there are mammal species. This means 7000 different ways of saying ‘good morning’ or ‘what’s for dinner?’ Large as the number of extant human languages is, there were probably as many as 12,000 to 20,000 at the peak of language diversity around 10,000 years ago, before agriculturalists began to spread across the globe and replace many hunter-gatherers’ cultures. And 7000 languages pales in comparison with the

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possibly hundreds of thousands of different languages we have ever spoken throughout human history.

This diversity means we are perhaps the only species whose members cannot all communicate with each other. Indeed, it is as if the different human-language groups have come to act almost like different biological species. But why would humans have evolved a system of communication that effectively cuts them off from other members of their own species? Over the past few years my research group and I have been studying human languages using

ideas drawn from the theory of evolution by natural selection, ecology and biogeography, and those studies are providing some intriguing answers to this question.

Why so many languages?

Modern humans evolved in Africa as early as 200,000 years ago, and by perhaps 60,000 to 80,000 years ago had migrated out of Africa to establish a permanent presence in the rest of the world. We expect new languages to arise as people spread out and occupy new lands, because as soon as groups become isolated from each other their languages

Punctuational bursts and language ‘divorce’ Our research suggests that, throughout history, human societies have had a tendency to divide into smaller competing groups as soon as they can control enough food and other resources to support themselves. In the rich environment of the tropics, smaller numbers of people can form a viable group

Numbers (top) and densities (bottom) of languages and mammal species at each degree of latitude in North America. Both trends show the decline in density towards the poles characteristic of Rapaport’s rule.

and this might be why we find so many different societies there. Over time, these smaller groups develop their own customs and rules and after just 500 years of isolation they could be speaking a new language.

The high density of languages in the tropics suggests that language is important for more than just communicating; we also use it to establish and preserve tribal identities, to distinguish ourselves from others and maybe even to prevent eavesdropping.

There are intriguing anthropological accounts of tribes deliberately changing elements of their languages – mostly vocabulary – for exactly these purposes. A group of Selepet speakers in New Guinea met one day and collectively decided to change their word for ‘no’ from bia to bune, to be distinct from other Selepet speakers in a neighbouring village. The change was made immediately. One can only sympathise with anyone who was away hunting at the time.

To see if this ‘language as identity’ effect held more generally, we studied large families of related languages, including the Indo-European languages (Western Europe, Iran, Pakistan and much of India), Austronesian languages and Bantu languages of Africa. By building family trees of these languages – called phylogenies – we could see the number of times a contemporary language had split or ‘divorced’ from a related language throughout its history.

Some had a history of many of these splits, others far fewer. We found that the more divorces in a language’s history, the more it had departed from its ancestral or ancient language in its vocabulary. It is not just that

these languages have a longer history – all of the languages we compared trace their history back to a common ancestor.

It seems, then, that when languages split they experience short episodes during which they change rapidly, or what evolutionary biologists have called ‘punctuational’ evolution. American English might itself provide an example. Many of the peculiar spelling differences between British and American English – such as the tendency to drop the ‘u’ in words like colour and honour – arose almost overnight in a punctuational burst of change when Noah Webster introduced his American English Dictionary at the start of the 19th century. Webster deliberately changed these spellings insisting that ‘As an independent nation, our honor requires us to have a system of our own, in language as well as government.’

Future of language diversity What does the future hold for languages?

In short, mass extinction. Even though contemporary languages continue to evolve and diverge from each other, the rate of loss of minority languages now greatly exceeds the production of new languages. Currently around 30-50 languages disappear every year as the young people of many small tribal societies adopt majority languages spoken nearby. This rate of loss equals or exceeds (as a percentage of the total) the loss of biological diversity through loss of habitat and climate change. The increasing interconnectedness of the modern world along with mass communication is having a homogenising effect on language. Already around 15 out of our 7000 languages account for around 40 per cent of the world’s speakers, while the majority of languages have very few speakers at all. This is the effect of people leaving their native languages and heading towards majority ones.

There is no reason to believe that this loss of linguistic diversity means the world is losing unique styles of thought; contrary to a widely held belief, our languages do not determine how we think. But the loss of languages often does coincide with the loss of cultural diversity, so the world is steadily becoming a more culturally uniform place. n MORE INFORMATION Mark Pagel is a fellow of the Royal Society and Professor of Evolutionary Biology at the University of Reading.

E-mail: m.pagel@reading.ac.uk His book Wired for Culture: Origins of the Human Social Mind was published earlier this year by Penguin (UK) and Norton (US). www.evolution.reading.ac.uk

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Graph reprinted by permission from Macmillan Publishers Ltd: Nature, Vol 428 pp275-278, copyright 2004.

begin to drift apart. We see this in modern times in the differences between British, American and Australian English.

But the real puzzle is that we see the greatest diversity of human languages not where people are most spread out, but where they are most closely packed together.

Take the case of Papua New Guinea. That relatively small land mass – only slightly larger than the American state of Texas – hosts 800–1000 distinct languages, or around 15 per cent of all languages spoken on the planet. Incredible as it sounds, there are parts of north-east Papua New Guinea where a new language can be found every few miles. By comparison, in China, which is roughly 12 times the size of New Guinea, only about 90 languages are spoken. Why? One of the best known trends of biogeography is Rapaport’s Rule, which describes the great increase in the diversity of species as you move from the poles to the Equator. Could Rapaport’s Rule hold true for human languages too? Anthropologist Ruth Mace and I decided to investigate.

We started by gathering information on the distribution of around 500 different Native American tribes before they had any contact with Europeans. We used this to plot the number of different language groups found at each degree of latitude in North America, from the Equator to polar regions. We found more languages per unit area in lower latitudes with only a handful at extreme northern latitudes.

For comparison, we then plotted the number of different mammal species at each latitude. To our surprise, the two sets of numbers fell almost on top of each other.

Human language groups seem to partition the landscape much like biological species do. It might not be surprising that few mammal species and few language groups are found in the polar regions – after all the landscape is harsh. And the large numbers of different species in the tropics might just reflect the variety and richness of resources in that environment. But, unlike other animals, humans are all the same species, so why are there so many different language groups in this region instead of one large and cooperative society?

FEATURE

One of the scientists working inside the aircraft.

The smoke detectors O Wildfires affect up to 20 million hectares of northern forests every year, and they don’t just cause damage on the ground – the plumes of gases they release are a major source of air pollution. Sarah Moller and colleagues spent part of last summer flying over Canada to learn more about them.

n 13 July 2011, I was at Halifax airport in Nova Scotia, to meet the BAe-146 UK Atmospheric Research Aircraft (ARA). The ARA would fly through the plumes from Canadian forest fires, to measure and analyse the cocktail of gases and particles they release into the atmosphere.

Our project studies the polluting effects of fires in boreal forests, which means the subarctic – north of 50°N. This type of fire is often called biomass burning. Locally the consequences are obvious; fires remove vegetation, endanger life and fill the air with thick black smoke. But the wider impact is harder to see.

The smoke plumes contain important atmospheric pollutants – carbon monoxide (CO), nitrogen oxides (NOx), carbon dioxide (CO2), methane (CH4) and black carbon – which affect air quality and how much sunlight reaches the Earth’s surface.

Prevailing winds carry pollutants from North American fires across the Atlantic Ocean to the UK and the rest of Europe, potentially affecting air quality there too.

That’s where our project comes in. Our challenge is to understand how these chemicals interact as the plumes travel, and specifically how they might affect air quality in the UK. It’s not just a case of measuring the different pollutants

Shaun Lowe/istockphoto.com

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though. As plumes age, the chemicals they contain react with each other and the background air, so the pollutants that reach Europe will not be the same as those in the plume when it was emitted. This means we also need to know the age of the plume and understand how its chemistry changes over time, to let us predict what the air will be like by the time it reaches the UK. We were particularly interested to see if ozone is produced or destroyed in ageing plumes. Ozone irritates our lungs and is an ingredient of the morning smog you sometimes see over cities. It is also a greenhouse gas. If chemicals from boreal forest fires produce ozone over

and how the computer predictions of the plume location would compare to our measurements.

Unfortunately, we didn’t yet have permission to fly below 13,000ft (around 4000m), so for most of the flight we were above the cloud and saw only minor fluctuations in the concentrations of the chemicals we were looking for; tantalising hints that there would be something exciting to measure, if only we could get low enough.

Armed with enough data we can begin to compare what we are seeing in the air with our computer model’s

reported in Ontario, but when we got there the previous day’s rain had put many of the larger ones out and all we saw were a few smouldering remains. Nevertheless, our measurements were worthwhile; they showed different concentrations of pollutants to those we’d measured before, and even some compounds that we had not seen at all during our other flights.

One of the most interesting aspects of our work is when we see things in our data that the chemistry in the computer models can’t explain, and we need to investigate to find out why. Three of our flights – beneath the path of the NASA Aura satellite, over Dalhousie University’s groundbased atmospheric measurement station, and around the launch site for balloon measurements of ozone at Goose Bay – will enable us to compare our own measurements with those taken using different types of instruments and methods; a useful check

Dirty layers clearly visible against the clouds.

the UK, it could combine with the UK’s own emissions to push background levels above safe limits.

To work out the best places to plumechase we used a map of fires that were currently burning and the expected emissions from these fires. We estimated the emissions we would expect from fires using studies that other people have done on biomass burning. We then ran a model that used these expected emissions to predict how much CO we would find at a given location. We would pick the area of highest CO concentration for the next day’s flying.

We factored in the weather too, because rain ‘washes out’ some chemicals and changes what’s going on in the plume.

Once in the air we know we’ve found a plume when we detect chemicals that couldn’t have come from any other source, in particular acetonitrile, hydrogen cyanide and black carbon particles – our biomassburning tracers. Seeing several of these chemicals together is a good sign we’re in the right place. They can be hard to find though; sometimes they settle into thin layers at different altitudes which are easy to miss.

The first science flight out of Halifax was a bit of a let-down. We were all excited to see how well our instruments would work, how high the concentrations of different compounds would get in the plumes,

prediction of what should be there.

The model simulates interactions between different chemicals and tells us what we should expect to see after the plume has been around for a few days.

So we can begin to understand how what we measure might relate to what was in the plume at the beginning.

We were quietly hopeful as we set off again the next morning, this time with permission to fly lower; sure enough things started to happen on our screens soon after take-off. First we saw rising CO concentrations, followed by some black carbon particles, and then my screen started showing a steady increase in reactive nitrogen; it looked like we were flying directly into an aged plume.

The chat over the radio increased as people shared their data and found correlations between methane, hydrogen cyanide and CO. At one point the CO shot up to a concentration that the chemistry operator, Steph, declared to be the highest he had seen in all his time on the aircraft. This flight was definitely more exciting and reassured us that we were in the right place.

That was the first of a series of flights during which we successfully measured plumes that were a few days old. What we needed next was more information about younger plumes. Several fires had been

which can highlight potential problems in the data.

After three weeks enduring long hours and the rather limited food options around the airport, we had managed to collect important data from both fresh and older plumes. Analysed alongside information from previous fieldtrips, this will be a useful step forward in our understanding of the impact of these plumes on European air quality. The excitement of the fieldwork is over but the hard work to tease out the answers in the data promises to be just as rewarding. n

MORE INFORMATION Dr Sarah Moller is a postdoctoral researcher at the University of York.

E-mail: sarah.moller@york.ac.uk BORTAS – Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites. www.geos.ed.ac.uk/research/eochem/ bortas Blog: http://nerc-bortas.blogspot.com/ Podcast: http://planetearth.nerc.ac.uk/ multimedia/story.aspx?id=1108

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FEATURE

N

ightfall comes early in the Arctic in November, and it’s already getting dark as I drive along the narrow road which runs uphill from the small village of Fagernes at the end of Ramfjord. We are at 69 degrees latitude in northern Norway, about 40km from the city of Tromsø.

My passengers are two radio journalists from the BBC, making the final programme in a series about the Earth’s atmosphere. The first was about the troposphere, below 10km, where all weather happens, while the second focused on the ozone layer, at 40km, which protects our planet from solar ultra-violet radiation and powers the dynamics of the middle atmosphere.

Now their final programme will explore the ionosphere and thermosphere – the outermost reaches of the upper air, where our atmosphere gives way to the vacuum of space. So why come to such an out-of-theway location?

We’re heading for the main site of the EISCAT Scientific Association, an international organisation with seven member countries, including the UK, whose subscription is funded by NERC. For 30 years, EISCAT has provided world-leading facilities for researchers studying the upper atmosphere and the space around Earth, known as ‘geospace’.

As we drive through the gathering gloom, my companions talk about the places they have already visited for their series, including their recent trip to Antarctica.

They seem to have been everywhere, and I’m thinking they’ll be hard to impress. Yet the conversation stops as we turn off the highway onto the gravel track leading up to the site.

Through the low trees, two huge radar dishes appear – the first a parabolic antenna 32 metres across, the second an enormous cylindrical antenna the size of a football field. I turn to the presenter in the passenger seat beside me and see that she’s grinning broadly. ‘OK, this is cool’, she says.

The reason the dishes have to be so big, I explain, is that we’re looking for a very weak signal coming from the ionosphere – the electrically charged layer of the Earth’s atmosphere, extending from heights of 80km upwards to more than 500km above our heads.

EISCAT works by transmitting highfrequency radio waves with a power of a few megawatts, in the form of coded pulses lasting about a millisecond. As these pulses travel through the ionosphere, they interact with electrons, causing each one to act like a tiny transmitter, re-radiating a minuscule fraction of the power that was transmitted. The power that makes it back to the radar is less than a million-millionth of that transmitted, but this is still enough to be detected by EISCAT’s very sensitive receivers.

Incoherent scatter The electrons that re-radiate this energy are controlled by the ions of the upper atmosphere, whose motion is, in turn, controlled by small-scale ‘ion acoustic’ waves. A radar like EISCAT is sensitive to those waves whose wavelength is half that of the transmitted signal – in this case, a few tens of centimetres. Such waves move randomly in all directions, but the radar is only sensitive to those moving towards and away from the radar along the direction of the beam.

The waves also lose energy to the particles they are composed of, in the same way that an ocean wave gives up some of its energy to a surfer. This means the frequency spectrum of scattered signals seen by the radar shows two broadened peaks, corresponding to the Doppler shift of the approaching and receding waves.

These peaks’ size and shape are very sensitive to some fundamental properties of the upper atmosphere, such as the density of electrons, the temperature of the electrons and ions, and the speed at which the atmosphere is moving. So analysing the peaks tells us about these parameters, which are very difficult to measure in any other way. This makes EISCAT’s radar technique, known as incoherent scatter, a uniquely powerful tool for studying the upper atmosphere.

We’re not just here to record sound bites for Radio 4. In EISCAT’s prefabricated accommodation block, affectionately known as ‘The Hilton’, we meet up with Dr Andrew Senior and Dr Steve Marple, from the

There’s still plenty we don’t understand about what’s going on hundreds of kilometres above our heads, where the atmosphere meets space. But we do know it can be crucial for life down here, causing phenomena that range from magnificent polar auroras to the violent solar storms that can knock out communications satellites and damage power grids. Ian McCrea explains how a facility deep in the Arctic Circle is helping unravel the mysteries of space weather.

Somewhere over the 14

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e radar

they are becoming increasingly blasé about the sight of those big radars. All they want to know is, when will they see the aurora?

Unfortunately, the sun is just awakening from one of the longest periods of low activity in its recent history.

When solar and geomagnetic activity are low, as they are during our stay, the auroral oval – the area within which the aurora appears – remains tantalisingly north of Scandinavia, and our night skies, although clear and starry, are free from the ‘Northern Lights’ which I foolishly promised they would probably encounter during their few days here.

there’s still no aurora. About midnight, I bid the journalists a frustrated goodnight and we retire to bed. Within minutes, however, a call comes from Andrew that the All-Sky Camera is seeing a weak auroral arc.

We all rush outside, just in time to see the show beginning at last, with curtains of red and green light filling the northern sky. Despite the bitter cold, journalists and scientists alike spend the next hour outside, taking pictures, recording ourselves as we describe what we are seeing, and being genuinely awed by something that, however often you witness it, is still one of the world’s most amazing natural wonders.

And so, finally, the Lancaster team return The reason the dishes have home with some good data to analyse, the BBC to be so big is that we’re folks have done enough recording for about a day looking for a very weak signal. of radio, never mind a 30-minute programme – This is good news for the Lancaster team, and I have the satisfaction of knowing that who can work without any interference from EISCAT, with a little help from Mother auroral processes which might confuse their Nature, has given them at least part of what results, but bad news for my radio crew, who they all came for. n are becoming increasingly despondent.

Finally, it is our last night. The skies are clear and starry again. The geomagnetic activity seems to be ticking upwards but

MORE INFORMATION Dr Ian McCrea is head of the UK EISCAT Support Group at the Rutherford Appleton Laboratory.

Email: ian.mccrea@stfc.ac.uk

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NASA

University of Lancaster. They’re working with another EISCAT facility, the HF ‘Heater’ – a powerful short-wave transmitter which transmits radio waves which couple to other natural wave frequencies in the ionosphere. This lets them transfer energy into the upper atmosphere, perturbing it in a controllable way, and use the radar dishes to measure how it responds.

As well as helping to make a radio programme, I will be assisting Steve and Andrew with their measurements. For the next three days, this involves the glamorous task of driving to a small shed in the woods, where they have set up a spectrum analyser to measure Stimulated Electromagnetic Emissions (SEE). SEE is another kind of radio wave, generated when the heater transmissions interact with the ionosphere.

Learning about SEE, and how it can be excited artificially, helps the Lancaster team understand how waves and charged particles exchange energy naturally in the Earth’s environment. While they may sound obscure, these wave-particle interactions produce the very energetic particles found in the Earth’s radiation belts – a major hazard for satellite operators, because of their ability to penetrate through spacecraft shielding into the sensitive electronic systems beneath.

Similar ‘space weather’ processes are responsible for accelerating particles near the poles, causing them to cascade downward into the Earth’s atmosphere, where they produce the dazzling light show known as the aurora.

The aurora. Neither of my journalist friends has ever seen it, and as the days go on

FEATURE

Eyes

in the sky

S

ending satellites into orbit isn’t a hobby for the cheapskate. Each launch costs millions, and if anything goes wrong on the way up you can kiss that cash goodbye.

But for every dollar spent, satellites provide invaluable information we could never gather from the ground. Bristling with sophisticated sensors, they monitor vast swathes of Earth and its atmosphere, repeating their measurements every orbit. This gives scientists long-term and almost real-time information about changes to our planet, which they once had to estimate from a handful of terrestrial instrument stations.

Here are just a few examples of satellite applications from the last few years:

n The same Global Positional System (GPS) signals used in your sat nav can measure movements of the Earth’s crust as slow as a millimetre a year.

This reveals tiny deformations and patterns of strain which can indicate where disaster may strike next – information that could save thousands of lives around the world. n The GOCE satellite – Gravity field and Ocean Circulation Explorer – measures variations in Earth’s gravity which, until now, we’ve only known about in general terms. GOCE has already enabled scientists to map gravity more precisely than was ever possible before, and will carry on collecting data until 2013. n The Soil Moisture and Ocean Salinity satellite, SMOS, is transforming our understanding of how seawater’s saltiness varies in different parts of the oceans, and of the varying degrees of moisture in soils all over the world.

(See p24 for more details.)

n GPS has a range of other environmental science applications too – everything from tracking migrating animals to monitoring longterm changes in the topography of Antarctic ice. n Infra-red imaging has revealed pyramids and settlements that have been buried for millennia under Egyptian sands. Because the buildings are denser than the overlying sediments they absorb heat differently from their surroundings and can be detected from space even if there’s no sign of them on the ground. n Scientists are using satellite-based LIDAR (light detection and ranging) to investigate everything from weather processes to the intricacies of rainforest canopies. Just as RADAR uses radio waves, LIDAR senses its target’s distance or speed from how long it takes for a laser to be reflected back to its receiver.

n Cryosat 2 uses pulses of microwave energy to obtain detailed measurements of Arctic and Antarctic ice – vital to our understanding of the relationship between climate change and the poles. The satellite is also shedding new light on patterns of ocean circulation and sea-level rise.

(See p22 for more examples of how space observation is transforming polar science.) n When the sun’s energy reflects off the Earth, some of it is absorbed by atmospheric gases like carbon dioxide and methane. Different gases absorb energy at different wavelengths, so researchers can monitor their levels using satellites to detect the different wavelengths of radiation that make it back out to space. This is giving us a more sophisticated understanding of the carbon cycle and how human activity is affecting it.

For more information, visit the National Centre for Earth Observation at www.nceo.ac.uk

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FEATURE

Putting data to work n Road construction, building foundations and pipeline-laying depend on the detailed data in the National Geoscience Data Centre on the superficial deposits overlying bedrock.

Data

n The Intergovernmental Panel on Climate Change will base its next assessment report on climate model data held at the British Atmospheric Data Centre.

for all

n 60 years of aerial photographs of floating Antarctic ice shelves in the Polar Data Centre provide the information needed to determine how quickly they are retreating as the area warms.

At the heart of all of our scientific theories and models are the data we collect by experiment and observation.

The quality of our science is inextricably linked to the quality of these data, many of which are unique. Leilani Smith describes how NERC is investing in the growth of this valuable asset.

n 30 years of carefully-managed data from the Antarctic first demonstrated that CFCs were destroying ozone in the upper atmosphere. n Tidal data from the British Oceanographic Data Centre show the pattern of storm surges in the North Sea – information that is critical for deciding on investments in coastal sea defences.

Storm surge heights in the North Sea.

W

e live in a data-rich age. But to keep the ‘knowledge economy’ of the 21st century running, to examine questions that cross disciplines and recognise patterns and trends of change, we need to actively manage and conserve our data. We also need to make them accessible, so we can realise their full potential.

NERC has developed a federation of data centres, which is responsible for maintaining its data and making them available to all users, not just NERC researchers but others from science, commerce, government and education as well as the general public.

The range of data held is vast, covering all aspects of environmental science from the atmosphere through Earth systems, marine and terrestrial, as well as temperate and polar.

The data come in an amazing variety of forms – from aerial photographs to Arctic plant life, digital data to drill cores, fossils to freshwater samples, maps to monitoring

data. Yet all this is organised, indexed and quality-controlled.

These data holdings provide a resource which is used for new research, investigating key environmental challenges such as climate change, supporting government policy in areas like conservation of endangered species or managing water quality, supporting infrastructure development and commercial enterprise.

Looking after this diverse and vast quantity of data is a challenge, not least in keeping up with changing technologies, devising standard formats to make the data easier to use across different disciplines, and meeting users’ expectations for accessing and downloading data on demand.

To meet these challenges, NERC is working with partners including the British Library, higher education institutions, the Digital Curation Centre and international research bodies. With a data policy which provides the foundation for all its data to be used freely, by anyone for any purpose,

n The Environmental Information Data Centre’s records of insects and plants form the basis for evidence of how global change is directly affecting UK biodiversity.

NERC is leading the way in publishing data. This includes issuing Digital Object Identifiers (DOIs) to enable data citation which recognises the contribution of its creators. n

MORE INFORMATION Leilani Smith is Communications Manager for the Science Information Strategy Programme.

Email: lsmith@bgs.ac.uk . Further information on the data centres, their holdings and datamanagement activities can be found at www.nerc.ac.uk/research/sites/data/

NERC DATA CENTRES British Atmospheric Data Centre (BADC) National Geoscience Data Centre (NGDC) NERC Earth Observation Data Centre (NEODC) British Oceanographic Data Centre (BODC) Polar Data Centre (PDC) Environmental Information Data Centre (EIDC) UK Solar System Data Centre (UKSSDC)

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FEATURE

Not just a pile of old dung How did bat and bird droppings help scientists reconstruct 40,000 years of climate history and species evolution in south-east Asia? Charlotte Bryant gives us the gory details.

R

Clockwise from top left: An unlucky bat on the cave floor.

Digging in the guano on the cave floor.

A roost of bats.

Ammonia levels can be lethal.

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esearchers Chris Wurster and Michael Bird have spent many years sampling guano deposits in the caves of south-east Asia, and tales of their fieldwork are enough to put anyone off joining them.

The guano and urine from millions of cave-roosting bats and birds can produce levels of ammonia lethal to humans, and the bacterial activity in large guano deposits can result in dangerously low levels of oxygen.

Then there are the flesh-eating beetles, which gobble up the occasional bat unlucky enough to slip off the roost.

Fortunately, given the less-than-savoury conditions, the sampling process simply involves digging a pit. But you could be forgiven for asking why anyone would willingly venture into such an environment more than once. The answer is that deep layers of undisturbed guano can give us important information about what our planet used to be like.

The guano doesn’t tell us this directly; instead it contains proxy information – a proxy being anything that can be used to infer something else. In this case, the guano contains the hard exoskeletons, or ‘cuticles’, of the insects the bats have eaten, and the chemical composition of these exoskeletons is a proxy for the type of vegetation the insects themselves were feeding on. If we know what vegetation was growing when the insects were alive, we can infer what the climate was like.

In tropical regions scientists generally use proxies from lake sediments to reconstruct past environments, but these can be surprisingly hard to find. Semi-arid regions

don’t have many lakes and those they do have are prone to disappearing entirely during drier times! So the large populations of bats in semi-arid and tropical regions provide a great source of information for environmental reconstruction.

The thickest guano deposit Chris and Michael have found so far is in Niah Great Cave in Borneo, where the oldest modern human remains in south-east Asia were found. So this technique can tell us about human evolution too.

The origin of faeces One particular conundrum that guano has proved invaluable in solving involves the biodiversity of south-east Asia. This region is characterised by many small and some very large islands, separated by shallow continental seas or deep oceanic trenches.

Changes in sea level have produced the many different sizes of these islands and affected the way they are connected together and to mainland Asia.

Each time a new land bridge was created by falling sea level, plants and animals could cross into new territories. Each time an island was cut off by rising sea levels, the plants and animals began to evolve uniquely to that island. This partly explains why this area is such a biodiversity hotspot, containing 25 per cent of Earth’s species on just 9 per cent of its landmass.

Even so, considerably more diversity exists in this region than you would expect, and the reasons why are the subject of some debate. Some of the larger landmasses, such as Borneo and Sumatra, have been connected for most of the past two million

years, yet some animals, like orangutans, have evolved into different species on each island.

Were these forest specialists unable to migrate between Borneo and Sumatra because the connecting land bridge was too dry for forest vegetation? Some people think the bit of south-eastern Asia exposed during the last ice age (known as Sundaland) was covered by an unbroken swathe of tropical rainforest around the Equator.

But others believe the landmass had a

Once they had separated the insect cuticles from the guano, the next step was to find out what the environment was like when those insects were alive, by identifying the kinds of plants they were living on.

Of isotopes and orangutans We can distinguish between grasses and other vegetation – shrubs and trees – from the way they fix atmospheric carbon dioxide to organic carbon during photosynthesis.

Plants use either three or four carbon atoms in this process; hence we call the two The guano and urine from alternative methods they use the C3 and millions of cave-roosting C4 pathways. In the bats and birds can produce levels tropics, almost all of ammonia lethal to humans. grasses use the C4 pathway, while other plants use the C3 pathway. dry interior and that tropical rainforests These differences are revealed by isotope shrank back into discrete areas, meaning analysis. Isotopes are different forms of the Borneo and Sumatra were effectively same element; they have the same number of separated by a desert from the perspective of rainforest specialists, if not by the sea. Could protons but a different number of neutrons in their nuclei. It turns out that the ratio of information preserved in guano deposits carbon isotopes 13C to 12C in plants using help us understand which of these scenarios the C3 and C4 photosynthetic pathways are is more likely? different. The cuticles of insects feeding on To find out, Chris and Michael first these plant types reflect the isotopic ratio of sampled guano from caves across different their diet, and so the carbon isotope ratios parts of Sundaland – Batu Caves near in insect cuticles reflect the proportion Kuala Lumpur on mainland Malaysia, Niah of grassland to forest in past tropical Cave in northern Borneo and two caves in environments.

Palawan, Philippines. These deposits date The carbon isotope ratios and dates from back over 40,000 years, and included the each sample site suggested that tropical height of the last ice age. The depth of each rainforest, unaltered by climatic changes, sample was carefully recorded, so that the had provided a continuous habitat for species sampled layers could be dated to reveal the in northern Borneo, near Niah. sequence of environmental change.

But it also showed that much of Sundaland must have been drier. In contrast to today’s tropical rainforest there was much more open savanna vegetation during the last ice age, and this could have prevented forest species from mixing or migrating – which may explain why geographically close areas like Borneo and Sumatra have their own species of orangutan.

The results also raise the intriguing possibility that ancient humans, adapted to the savannas of Africa, could have rapidly crossed Sundaland and migrated to the savannas of northern Australia. Direct evidence for this rapid movement may currently lie under the sea.

So it turns out that these cave deposits don’t just tell us about how orangutans and other species spread around south-east Asia – they may also inform the understanding of our own species’ early spread. Not bad for a few thousand years of raw sewage! n

MORE INFORMATION Dr Charlotte Bryant is head of the NERC Radiocarbon Facility, Environment, at the Scottish Universities Environmental Research Centre, East Kilbride.

E-mail: c.bryant@nercrcl.gla.ac.uk Professor Michael Bird and Dr Christopher Wurster (both now at James Cook University, Cairns) carried out this work while at the University of St Andrews. www.pnas.org/content/107/35/15508 www.gla.ac.uk/nercrcl/ www.c14.org.uk/

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FEATURE

Shale: no great shakes?

Shale gas is the energy miracle that’ll keep the lights on once the oil runs out. Or is it the looming menace that’s going to trigger deadly earthquakes and set fire to our tapwater? Tom Marshall talks to Mike Stephenson of the British Geological Survey (BGS) to sort truth from fiction.

Tom: What is shale gas and how do we get at it?

Mike: Shale is by far the most common sedimentary rock on Earth; there are many thousands of cubic kilometres of it beneath the surface. Usually a few per cent of its volume is organic matter.

Like other fossil fuels, this is formed from the remains of ancient living things. Under huge pressures and temperatures underground, and over huge swathes of geological time, this organic carbon gets cooked up to form methane.

To get at it, we have to drill down to the shale and pump in highpressure water, breaking the rock up so we can pump out the gas.

There’s a fundamental link to the climate here: this ancient carbon cooled the Earth when it was absorbed and sequestered; releasing it back into the atmosphere will cause warming.

Tom: How significant are the UK’s reserves in the context of our energy needs?

Mike: Shale gas isn’t like oil or natural gas; there isn’t a fixed amount of it down there waiting to be extracted. It’s more like we’re producing it – in the US they talk about underground shale as ‘the gas factory’. There’s as much gas down there as we choose to produce by fracking the shale, so it’s really about how much fracking we want to do. World shale gas reserves are estimated at 450,000 billion cubic metres (BCM).

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Shale gas is a natural gas locked in the matrix of low porosity shale rocks.

In the US they’ve been incredibly successful in growing the industry – shalegas production more than tripled between 1996 and 2006, and natural gas now meets 20 per cent of the country’s energy needs.

One recent study suggested this will be around 45 per cent by 2035, partly thanks to abundant shale gas. But we’re a much smaller and more densely-populated country, and probably less accustomed to subsurface activity, so we may want to take things more slowly.

It’s certain that shale has much of the Earth’s reserves of organic material, but there’s a lot of variation in estimates of its energy potential. To give you an idea, the company that’s fracking in the Bowland Shale around Blackpool, Cuadrilla, says there’s about 7BCM of gas down there; at BGS we think it’s more like 0.2BCM. So the numbers are quite uncertain, but everyone agrees our shale-gas resources are significant.

Blackpool – so there’s a huge amount of hard, dense rock in between. I can’t imagine how the gas could possibly make it through this and into aquifers. But that feeling’s not really good enough. The public and policymakers have legitimate concerns, and we should be producing the science they need to make informed decisions.

A more realistic concern is that the casing around the boreholes could fail near the surface, letting methane escape into groundwater. This is certainly possible, although the energy industry has a lot of experience with designing casings that don’t leak – there are hundreds of thousands of oil wells around the world, and most of them work fine. But casings do go wrong, and sometimes this has catastrophic consequences, as we saw with the Deepwater Horizon disaster.

In the US it may be that there’s been a certain amount of cowboy fracking going on, and that contractors haven’t always been as careful as they should be.

[For an example, see www.epa.gov/region8/ superfund/wy/pavillion/] But in a lot of cases what’s probably happening is that the methane in drinking water is a naturally-occurring gas created by microbial activity, and has nothing to do with fracking.

Tom: How can we tell if methane was there naturally or not?

Mike: One way is to analyse the ratio of different isotopes of carbon in the methane. Biogenic methane (produced by living things) is much younger than the thermogenic (produced by heat) methane that’s cooked up deep beneath the surface, which is what we’re trying to extract for energy.

The whole area’s a perfect This means it breeding ground for has a different hyperbole and paranoia. But it’s also mixture of carbon isotopes. a perfect opportunity for science!

So if groundwater contains methane, in theory we should be We estimate there’s something like able to tell where it comes from, and whether 150BCM of shale gas under the UK, which it was there naturally or is the result of would be a significant boost to our energy shale-gas extraction, although the situation reserves. becomes more complex if there has been mixing between methane from different Tom: People are worried that fracking will sources. It’s not cut and dried, but these contaminate drinking water with methane. techniques could certainly help trace the Do you think that’s a real risk? source of methane.

Mike: For a geologist, it’s hard to believe In a lot of the high-profile cases in the US fracking itself could do this. The distances we can’t be sure what caused the problem are just too great. The aquifers that provide because we don’t know what the situation groundwater are only a few hundred feet was before fracking started. It’s vital that we deep. The shale deposits we’re interested do monitoring and establish a baseline, or in are far deeper than that – the Cuadrilla we’ll never be able to tell what’s natural and fracking was about three miles beneath what’s caused by shale-gas extraction.

Tom: Beyond any risks for groundwater, there are also concerns that fracking could trigger earthquakes. Are they realistic?

Mike: The earthquakes in Blackpool last year were caused by fracking; there’s no doubt about that. But they weren’t responsible for the damage to structures in the area that some people have claimed.

Fracking does cause tremors, but they’re generally far too small to be noticeable.

From a geologist’s perspective, there are faults everywhere underground and they move all the time; if you add high-pressure water they’ll probably move a little more.

Generally this isn’t a problem; these quakes aren’t powerful enough to cause damage – they happen naturally all the time in the UK. But we should be giving people the information they need to understand the risks, rather than just telling them there’s nothing to worry about.

Tom: What should be done?

Mike: Again, we need better monitoring so we know what the situation was before fracking started. There’s a proposal being considered at the moment under which companies would use a traffic-light system, so that if there is any sign of a build-up of pressure they stop for a few hours and let things settle down again. Probably there will need to be some kind of independent monitoring of fracking operations, perhaps by an organisation like the BGS. Tom: It seems there’s surprisingly little research available on this. In your recent presentation to the Royal Society, you identify just two papers in the area.

Mike: The energy companies have done lots of research, but they don’t release it.

The public don’t really understand the process and its risks, but they have justifiable concerns. The whole area’s a perfect breeding ground for hyperbole and paranoia. But it’s also a perfect opportunity for science! If we can get the science right, we can support regulators, reassure the public and make sure that if something goes wrong, we know about it and can hold the appropriate people responsible.

MORE INFORMATION Professor Mike Stephenson is head of energy science at BGS. He recently gave a presentation to the Royal Society about the possible risks of shale-gas extraction.

Listen and watch an accompanying slideshow at: www.foundation.org.uk/events/audios/ audiopdf. htm?e=448&s=1226

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FEATURE A lake on the surface of the Greenland Ice Sheet.

Spotting ice from space Orbiting satellites and the sophisticated sensors they carry are transforming our ability to monitor even the furthest-flung parts of the planet. PhD candidate Allen Pope shares how he and his fellow students are using this unique data to explore Earth’s fast-changing poles.

N

ormally, the phrase ‘polar exploration’ conjures images of bearded men pulling sledges across barren, snowswept landscapes. In the century since Robert Falcon Scott’s doomed expedition brought back some of the first samples from the icy continent, research has leaped ahead into new frontiers: air and space.

There is no shortage of news and research about sea ice melting, glaciers all over the world retreating, ice shelves breaking up and ecosystems at both poles drastically changing.

Fieldwork is essential if we’re going to understand climate change, but airborne and satellite data give scientists unprecedented amounts of information on the polar regions, at a level of detail and over large areas that are just not possible from anywhere else. After all, globalscale changes mean we need global-scale answers!

Satellites let us researchers stay warm and safe rather than freezing after falling into a crevasse to take measurements. We can get data – quite detailed data, and at frequent intervals – across huge areas that are just too hard to get to otherwise, no matter how much we might want to do so.

Me, I found myself in polar research because I love to be outside hiking and cross-country skiing, and the next best thing to skiing across glaciers all the time is looking at pictures and studying them!

Through my work, I became involved in a project to share the skills

CryoSat-2 measures the ‘freeboard’ of floating sea ice – how far it protrudes above the water – with its sensitive altimeter. Once we know the freeboard, we can estimate how thick the ice is.

ESA /AOES Medialab

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Ian Willis, SPRI

Map of sea-ice thickness in the Arctic based on Cryosat-2 data.

Thanks to CryoSat-2’s orbit, we can see how thick the ice is close to the North Pole for the first time.

necessary to use remote imagery to study the poles with a range of graduate students in the UK and across the world. It turns out there are a lot of us using satellites to explore the poles!

At a summer school and workshop organised with the UK Polar Network, the Earth Observation Technology Cluster and the National Centre for Earth Observation, I got the chance to meet and profile a few of these young researchers – all doing exciting polar research from space!

How deep is that lake? Tell me what colour it is Lakes forming on ice might sound a bit odd, but that’s exactly what happens every spring and summer as the surface of the Greenland Ice Sheet melts. When these lakes drain through cracks and tunnels in the ice, the water makes its way to the base and can speed up the flow of the ice sheet, causing more icebergs to form and more ice to melt as it flows downhill to warmer areas.

To predict how much the ice will accelerate, Swansea University doctoral student Laura Cordero Llana is using satellite imagery which takes pictures not just in red, green and blue but also in the infrared – called multispectral images – to measure the colour of lakes in Greenland.

Deeper lakes have deeper colours, and Laura is working on the relationship between depth and colour to understand just how much water collects on Greenland’s surface, and how much makes it to the bed of the ice sheet. By finding out, she’s doing her part to peer into the future of Greenland’s ice!

Learning the language of a new satellite Cryosat-2 is an exciting new satellite recently launched by the European Space Agency specifically designed to study the Earth’s icy regions – also known as the cryosphere.

With any new sensor, there’s a learning curve – it takes time to understand what the data being beamed back from space is saying. That’s precisely what Marta Zygmuntowsca of the Nansen Environmental and Remote Sensing Centre in Norway is working on translating.

Open water, new (and hence thin and smooth) ice and older (thicker, rougher) ice all send back different signals, and Marta is using data from Cryosat-2 and ASIRAS – the same instrument as on the satellite, but mounted on an aircraft – to get a more accurate view of the extent, thickness and type of the sea ice which covers the Arctic Ocean.

Over the last decade, we have consistently seen below-average sea ice, with several new record lows being reached, so work like Marta’s that draws on data from new satellites is essential to keep tabs on the ice and how it influences global weather and climate, the biology and ecosystems in the north, and Arctic shipping and exploration.

CPOM/UCL/ESA

Greenlandic Ice As headline-making errors in the recent Times Atlas illustrated, identifying glaciers is an important and sometimes difficult task.

Greenland is huge, but many of the glaciers that ring the coastline are small.

That’s why Philipp Rastner, a PhD student at the University of Zurich, is working on techniques to analyse large amounts of highresolution satellite imagery to create a glacier inventory of eastern Greenland. Once he has completed this task, others will be able to use his technique in other glaciated regions, and the data will also be used to estimate how much these regions might contribute to global sea-level rise.

Ice thickness (metres) Water flowing under miles of ice We’ve all heard of radar – before GPS, it was what aircraft navigation depended on. Some of the pilots flying over Antarctica noticed that the ground was a lot closer to their plane than they expected, and that’s when they realised that radar at certain frequencies penetrates through ice!

Scientists use newly-developed radar systems to explore layers within the ice and what lies beneath. Radar data were used to discover hundreds of lakes beneath the Antarctic Ice Sheet, and now University of Aberdeen doctoral student David Ashmore is using the same data to explore water flow beneath the same ice.

Even more in Antarctica than in Greenland, the amount of water at the base of a glacier will change how fast the ice can flow. There, some ice is stagnant, but elsewhere, in zones called ‘ice streams’, it moves hundreds of times faster. By helping us understand how water flows underneath Antarctica’s miles of ice, David’s research is giving insight into how this ice will behave in the coming decades and centuries.

Polar exploration has come a long way since Scott, but the goals of understanding these amazing and important icy regions are the same. Many of us students are fascinated by finding out all we can about the Arctic and the Antarctic, not just by travelling there but by harnessing the immense power of data from another frontier: space.

Now that you’ve heard a little bit about the techniques behind the scenes, look out for our groundbreaking results in a newspaper near you… once we’ve finished our PhDs! n MORE INFORMATION Allen Pope is a PhD candidate at the University of Cambridge’s Scott Polar Research Institute, studying remote sensing of glaciers in Iceland and Svalbard. You can follow his updates on polar remote sensing on Twitter @PopePolar and find out more about other young polar researchers in the UK at www.polarnetwork.org and www.eotechcluster.org.uk. Email: ap556@cam.ac.uk See young researchers share their work as FrostBytes: www.apecs.is/events/montreal2012/frostbytes

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FEATURE

New satellite images are providing unprecedented global views of the distribution of salt and fresh water across the surface of the Earth’s oceans. Chris Banks describes how scientists at the National Oceanography Centre in Southampton are helping discover how accurate this new information is, and what it can tell us about the global water cycle.

Tasting the salt of the Earth’s oceans I

f you have ever tasted the water while swimming in the Mediterranean or Red Sea, you might have noticed how much saltier it tastes than the water around the coast of the UK. Even though seawater is much saltier than rivers and lakes, the salt content varies significantly across the Earth’s oceans. These variations have profound effects on the climate system.

For example, the UK’s climate is much milder than that found at other parts of the world at similar latitudes, like Canada or Russia.

This is because of the influence of warm Atlantic water transported northwards from the tropics by what is known as the Atlantic Meridional Overturning Circulation (MOC).

In fact, the Atlantic MOC is just one aspect of a global ocean circulation known as the thermohaline circulation. ‘Thermo’ comes from the Greek for heat or temperature, and ‘haline’ relates to salt.

Differences in temperature and salt content change the density of seawater, and this in turn drives the global ocean circulation.

In oceanography, the saltiness of seawater is known as its salinity.

Salinity represents the amount of salt dissolved in the water and is expressed as a ratio. The oceans’ salinity varies globally between 30

and 40 parts per thousand, roughly equivalent to 30-40 grammes of salt dissolved in a litre of water. With salinity around 40, the Red Sea holds some of the saltiest seawater on Earth, while the English Channel, with salinity around 35, is more typical of the oceanic average.

Until recently, the only way to measure salinity was by direct sampling, using salinity sensors on ships or buoys (thankfully not involving tasting!). However, even at the surface, there are vast regions of the oceans that are rarely visited, and this leads to an incomplete global picture.

The situation has improved markedly in the last few years, thanks to the international Argo programme. Today, over 3000 Argo floats drift freely across the ocean. Every few days, each float provides measurements of salinity, temperature and depth over the top 2000m of the ocean. Even so, with Argo floats typically spaced more than 300km from each other, our knowledge of global ocean salinity is still incomplete.

Earth-orbiting satellites give a unique global view of our planet.

Satellites have been measuring sea-surface temperature for the last 40

ESA - P. Carril

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The first map of salinity, or saltiness, of Earth’s ocean surface produced by NASA’s Aquarius satellite since it became operational on 25 August 2011.

NASA/GSFC/JPL-Caltech

years with increasing accuracy. Measuring ocean salinity from space is altogether more challenging, and, until the launch of the European Space Agency (ESA) Soil Moisture and Ocean Salinity (SMOS) satellite, was thought to be all but impossible.

To achieve the detail required to make out ocean eddies and river plumes using a conventional design, the satellite’s antenna would have to be prohibitively large, making it impossible to fit it inside a rocket.

In November 2009, ESA launched the innovative SMOS satellite – as you might guess from its name, this is designed to measure both the water content of land and the salt content of the ocean surface. SMOS was small enough to fit inside a rocket because of its unique unfolding Y-shaped antenna. Spanning 8 metres when deployed, the antenna comprises 69 small receivers. By

Less saline

features (for example, whitecaps and foam), all of which must be removed in order to extract the information about surface salinity. In addition, in the same way as we can see the sun, moon or stars reflected from the surface of the ocean, radiation at L-band is also reflected, so we need to make corrections to the measured brightness temperature.

One of the reasons the L-band wavelength was chosen is that it is ‘protected’ Measuring salinity can be like – broadcasting signals in this looking for a small candle band is not flame on a bright, sunny day… permitted, so ideally there combining the signals from these receivers, should not be any man-made sources. a much larger antenna can be synthesised – Unfortunately, there are a few sources that mimicking a technique commonly used in create radio frequency interference. These radio-astronomy. sources can be strong, making measuring salinity like looking for a small candle flame Remote sensing sea salt on a bright, sunny day. Some of the sources But how can SMOS measure salinity from can and have been identified (for example, space? The answer relies on a property due to incorrectly working television known as electrical conductivity. Essentially, broadcasts) and removed but others are how well seawater conducts electricity more problematic as they are the result of depends on its salt content; the saltier the powerful military radars that spill into the water, the more easily electricity travels measurement range of SMOS. through it. SMOS measures the natural All these issues lead to errors in single radiation emitted by the Earth’s surface at measurements of salinity that are too large a particular electromagnetic wavelength for the data to be used in many applications. of around 21cm, known as L-band. The The aim is for accuracy of 0.1 – accurate to strength of this radiation, known as the about 0.1g of salt in a litre – over 10-30 days brightness temperature, is related to the and 100-200km of ocean. conductivity of the surface.

SMOS takes measurements over the As a passive sensor, SMOS only entire ocean surface every three days, so by measures natural radiation, and does not averaging many individual measurements itself emit any signals, unlike lasers or we can improve the accuracy of the salinity radars. Unfortunately, this means that its observations. At the National Oceanography measurements are sensitive to many other Centre (NOC), we average SMOS data over factors that also influence the radiation at 1° (latitude) by 1° (longitude) boxes, and over that microwave frequency. a period of one month.

This includes effects from surface These gridded datasets have been temperature, wind, waves and other related compared with measurements from Argo

More saline

buoys and output from a UK Met Office model of ocean circulation. Initial results show that, away from coastal areas (that is, more than 100km from land), SMOS can reproduce variations in salinity across the oceans. We always knew that coastal regions would be problematic as land emits much more L-band energy than water, so measuring salinity is even harder – like looking into a dark corner on a sunny day.

In recent months, SMOS measurements of coastal salinity are markedly improved as ESA has implemented an improved processing system following feedback from NOC and other international investigators.

As well as these on-going improvements in data from SMOS, the future of measuring ocean salinity from space is bright. In June 2011, SMOS was joined by another satellite measuring salinity when NASA launched the US/Argentine Aquarius mission.

Aquarius uses very different technology from SMOS, but shares the same scientific goals, which benefit from good interaction between the scientists and engineers working on the two satellites to analyse and interpret these novel satellite datasets.

Results from these two innovative satellites along with data from Argo and other in situ measurements will improve our knowledge of ocean salinity. In turn, this will enhance our understanding of ocean circulation, and hence our ability to model climate and weather. n

MORE INFORMATION Dr Chris Banks is a member of the Marine Physics & Ocean Climate research group at the National Oceanography Centre in Southampton.

Email: chris.banks@noc.ac.uk.

International Argo programme: www.noc.soton.ac.uk/o4s/euroargo

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FEATURE

Simon Drew describes how scientists are sharing their knowledge to turn research into action to cut carbon losses from the landscape.

We’re all in it together M

ost of us now recognise that human activities are contributing to global warming, and there is a growing realisation that we should be actively managing the carbon-storage potential of natural environments – the Earth’s carbon cycle.

Plants use photosynthesis to extract CO2 from the atmosphere and store it in solid form in their bodies. In peatlands plants do not decompose fully when they die and the carbon they contain is then stored in the peat which is formed. Peat contains more carbon per unit of area than any other habitat on Earth and covers roughly 15 per cent of the UK and holds about 2300 megatonnes (million tonnes) of carbon.

If the UK loses just 5 per cent of its peatland the equivalent of a year’s worth of UK CO2 production will escape into the atmosphere.

So small changes can have a big effect, and this environment is vulnerable to changes in management practices and climate change.

Several large-scale activities have affected our peatlands over the last few decades, including extraction for fuel and compost, and managed burning for grouse shooting. After the Second World War there was a nationwide drainage programme intended to lower the water table and increase the amount of land available for sheep grazing. As the water table lowered the peat began to rot and give off carbon as CO2.

It has taken decades for us to realise the effects of these activities, and in some places efforts are under way to repair the damage. But modern developments continue to pose a threat. One of these, which has received little attention so far but is likely to become increasingly important, is wind farms.

The wild and windy conditions that promote peatland vegetation growth are also good for generating energy, so peatlands are a desirable location for wind turbines. These complex developments can involve removing peat for turbine bases, felling woodlands to provide unimpeded wind flow, and draining wetlands to build new roads.

Scientists can look into all the implications for the environment and the economy, but how do we know we’re asking the right questions, ones that will translate into practical solutions for the people who have to manage peatland environments every day?

Wind farms and wetlands This is where knowledge exchange (KE) comes in; where researchers and research users join forces to learn from each other and turn the science into action. I am the network coordinator of Carbon Landscapes and Drainage (CLAD), a KE programme that brings together a range of people with an interest in peatland management – including researchers, conservationists, regulators, developers and environmental consultants – to look at the problems associated with

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Peatland hydrology. Knowledge exchange between CLAD and Malaysian peatland researchers.

Simon Drew and Kenny Roberts installing a spectrolyser to measure in situ dissolved organic carbon in a stream draining a wind farm catchment.

CL AD has teamed up w developer, Scottish a ith a wind farm nd Southe Renewable rn Energy s, to fund a carbon is lost during PhD project on how win by quantify ing how m d farm construction uch carbo through d n escapes rain also makin age pathways. But the studen gu t is the carbon se of the sediment record to losses from s et context; w e can prob the site in a historic a e l carbon ex long-term port using changes in sediment loch and a deposited reservoir d in a raining the catchmen t.

Susan Waldron recalibrating water quality monitoring equipment.

carbon lost via aquatic pathways (streams and rivers) from peatlands when they are disturbed, particularly due to developments like wind farms.

It sounds worthy, but how does it work in practice? To create a successful KE network, you have to overcome some of the natural suspicions and competitive instincts that most of us are subject to – for example, the perception that academics are locked in ivory towers studying impractical research questions, or concerns that land managers aren’t always interested in scientific evidence when they make decisions.

But given the increasing interest in carbon management, it didn’t take much to get

people involved. The mutual benefits of cooperation and interaction were clear – the managers and practitioners get access to the latest science and thinking, while the researchers get an improved understanding of the mechanisms of change and management in peatlands – and the network quickly became largely self-sustaining.

CLAD aims to improve management practice through a variety of activities, some planned in advance, others ad hoc. We have established a series of annual meetings, each focusing on a particular topic; the first two covered how peatlands lose carbon in water and the role of drainage in restoring peatlands.

Other events are more practical; for example we ran a workshop demonstrating how to monitor carbon losses using new technology and techniques.

Some CLAD activities evolve according to the needs of the group. At our opening meeting some network members were particularly interested in learning to use an important new tool called the ‘Carbon Payback Calculator for Windfarms Build on Peat’. (This was commissioned by the Scottish Government to give developers a way to estimate how long it would take for a wind farm to ‘pay back’ the carbon released in building it, by letting us burn less fossil fuel elsewhere.)

So we invited the tool’s creators to a series of meetings, to demonstrate the calculator and answer questions from the people who would be using it. In turn the users’ feedback shaped updates to the calculator – knowledge exchange in action. Being able to respond to the needs of the group has been fundamental to CLAD’s success, keeping it relevant to everyone involved.

Direct research advances also flow from KE. We are field testing a spectrophotometer – an instrument that measures how much light water emits to let us make highresolution measurements of its dissolved organic carbon (DOC) content while in the field.

DOC is one of the most important ways in which carbon is lost from peat and until now DOC data has been gathered by analysing samples in the lab. This new technology means we can get more detailed (and therefore more useful) data in the field. It was of great interest to everyone in CLAD – not just the researchers.

One of the most important outputs of the project will be a set of guidelines that outline best practice for developing peatlands, to minimise the impact of development on carbon losses and to mitigate the effects where they are unavoidable.

For me, knowledge exchange has been an exercise in learning by doing so far, but a very successful one. Professionals working in the field are often tied up with the day-to-day concerns of their jobs, and KE networks like CLAD let us all quickly identify and share our most pressing needs and latest knowledge.

But CLAD has only made a small dent in all the issues surrounding peatland management. We predict a much stronger demand for this kind of work in the future. n MORE INFORMATION Dr Simon Drew is a member of the School of Biological and Environmental Sciences at the University of Stirling. He is also network coordinator of the CLAD project.

Email: simon.drew@stir.ac.uk www.clad.ac.uk

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PODCAST Q&A

The Antarctic ozone hole 25 years on

In May 1985, British Antarctic Survey scientists Joe Farman, Brian Gardiner and Jonathan Shanklin described in Nature their observations of large losses of ozone over Antarctica. The ozone layer is essential: it acts like a sunshield for the Earth, blocking ultraviolet B rays which can cause skin cancer. Just over two years after the publication of that seminal paper, governments around the world signed up to the Montreal Protocol to phase out the production and use of chlorofluorocarbons (CFCs) and other ozone-depleting chemicals.

Yet the ozone hole hasn’t disappeared. So what’s going on?

Richard Hollingham met Jonathan Shanklin in Cambridge to find out more about the discovery and why the hole is still there.

A false-colour view of the monthly-averaged total ozone over the Antarctic pole on 21 September 2011. Blue and purple colours represent the least ozone, and yellow and reds, the most ozone.

NASA Ozone Watch

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From left: Joe Farman, Brian Gardiner and Jon Shanklin. The instrument is a Dobson ozone spectrophotometer, used to determine stratospheric ozone concentrations. BAS

Richard: Jonathan, you were doing your research at the British Antarctic Survey’s Halley Research Station on the Brunt Ice Shelf in Antarctica when you made your discovery. And you’ve got one of the original handdrawn graphs with you showing the drop in ozone levels over time.

Jonathan: Yes, we’ve got the data from Antarctica which I’d plotted up and one of the key things was that we could see something going on in our data.

Richard: So, let’s look at this graph. It’s plotted by hand at a time before computers could even do this.

Jonathan: Yes, drawn on paper with a pencil and a ruler to draw the best-fit line through the data. But the point is, anybody can see that something is happening. You can see ever so clearly that ozone amounts are going down and that was absolutely key: once you could see something this systematic, then something must be causing it. My question was: what?

are very stable. They stay in the atmosphere for a long time. So, although the amounts of CFCs in the atmosphere are dropping, there are still so many up there that when conditions are right you’ll still get ozone destruction. Unfortunately you get those conditions over Antarctica every year, and this year we’ve had one of the deepest and largest ozone holes on record.

Richard: So then you made a correlation between this decline in ozone and CFCs?

Richard: When you first plotted the graph and published your findings in Nature, could you have imagined that it would lead to the Montreal Protocol?

Jonathan: Yes. People had speculated for some time that CFCs could affect the ozone layer, but they predicted it would happen high above the tropics. What we found was an effect low in the atmosphere, above the Antarctic; quite a different place. But because there was an expectation that CFCs could affect the ozone layer, we thought that was probably what was happening, and so then we plotted the graph. At a glance, you could see that there was a correlation between ozone amounts declining and CFC amounts going up.

Richard: OK, so the Montreal Protocol is a huge success in terms of environmental treaties, getting that done just two years after your discovery. Why, then, is there still an ozone hole over the Antarctic?

Jonathan: The Montreal Protocol has been incredibly successful. But these CFCs

Jonathan: When we first made the discovery we thought, well, this is a pretty obscure part of the world, it’s not going to have a global impact by any means. But it is a lesson in how quickly we can change our atmosphere. Between ozone depletion being detectable to it being a full-blown ozone hole happened in the space of about a decade.

Richard: The Montreal Protocol was a huge success when it comes to these sorts of treaties. Can this be repeated when it comes to global warming, to climate change?

Jonathan: There are differences. With CFCs, just about everyone was on side. The manufacturers were quite happy to switch to a different product, and it was very easy to do. Also the public don’t like ‘holes’, so calling it a hole struck a chord. Then there

was the link between increased ultraviolet light and cancer; cancer is one of the banes of today’s society, so if something is causing it we’ve got to get rid of it. So everything worked in favour of doing something about the ozone hole.

With greenhouses gases, it’s much harder.

First of all, ‘global warming’ sounds nice.

Secondly, it’ll take a very big change in people’s lifestyles to reduce their dependence on fossil fuels.

The oil industry in particular is rather reluctant to stop selling oil. There’s no cheap alternative that could be widely sold. I think we will be lucky to get a treaty that’s as effective as the Montreal Protocol was. n

MORE INFORMATION Jonathan Shanklin is an atmospheric scientist at BAS. Email: jdsh@bas.ac.uk Find out more about the ozone hole and related BAS science: www.antarctica.ac.uk/press/journalists/ resources/science/ozone.php This Q&A is adapted from the Planet Earth Podcast 22 November 2011. The full podcast and transcript are on Planet Earth Online: http://planetearth.nerc.ac.uk/multimedia/ story.aspx?id=1108

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2011 issues

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