The Carbon Control Knob by Island Press

The National Climate Seminar

The Carbon Control Knob

Richard Alley

Washington | Covelo | London

Copyright ÂŠ 2012 Island Press All rights reserved under International and Pan-American Copyright Conventions. No part of this book may be reproduced in any form or by any means without permission in writing from the publisher: Island Press, 2000 M Street, NW, Suite 650, Washington, DC 20036. ISLAND PRESS is a trademark of the Center for Resource Economics. Cover design by Maureen Gately Cover image ÂŠ khalus, iStockphoto.com

Introduction On November 2, 2011, Richard Alley participated in The National Climate Seminar, a series of webinars sponsored by Bard College’s Center for Environmental Policy. The online seminars provide a forum for leading scientists, writers, and other experts to talk about critical issues regarding climate change. The series also opens a public conversation, inviting participants to ask questions and contribute their own thoughts. Dr. Alley conducts research on the paleoclimatic record at Pennsylvania State University in order to understand the history, and perhaps the future, of climate change. In his lecture, Alley gave a concise overview of why we know what we know about climate change, and what that evidence can tell us about today’s warming planet. Alley not only provides an accessible science lesson, but also reveals his own greatest concerns about climate change and offers advice to those who want to stop debating the subtleties of climate science and act now. What follows is an edited version of Alley’s talk and the subsequent question and answer session. While some material has been cut and some language modified for clarity, the intention was to retain the substance of the original discussion.

The Carbon Control Knob Seminar by Richard Alley

I have the great good fortune to work on the history of climate. A longer version of my discussion here is available for free online at here When we read the history of climate, we get a very clear picture. It is indeed possible, with fairly high confidence, to figure out what climate was like in the past. We can recognize the deposits of glaciers spread across the landscape today and say, “Look, they’re in places that are now warm. But there used to be ice there; it must have been colder.” In the same way, we can reconstruct the factors that might have changed climate. We have some indications of how bright the sun was. We certainly have indications of volcanoes that were throwing up ash to block the sun. We can study CO2. For the last 800,000 years, we have had bubbles in ice cores. And we know that the recently trapped bubbles beautifully reproduce what’s been measured in the atmosphere. If we want to study periods earlier than those for which we have atmospheric measurements, we can go to Antarctica, to different places with different impurity loadings, different temperatures, different snowfall rates, and they have the same record. They are not being controlled by anything other than what was in the atmosphere. Our understanding of this is actually very good. Looking back through the oldest reconstructed ice cores, we can get a very good estimate of CO2 in the atmosphere. Older than ice cores, it’s not quite as obvious, but we still can get decent CO2 estimates. If you change CO2 in the atmosphere, the chemistry of the ocean changes. We’re now worried about ocean acidification, and the changes are recorded in some shells’ chemistry and isotopes. Changing CO2 in the atmosphere changes the 1

minerals that are deposited in evaporating lakes like the Great Salt Lake. When CO2 is more abundant, plants can be pickier about using the light isotope that reacts more easily. When CO2 is rare, they have to use what’s available and they use more of the heavy isotope. When CO2 is common, plants can actually grow leaves with fewer stomata: there are fewer mouths to breathe through because they can get enough CO2 and they don’t waste as much water. If we look at the big picture, what do we learn? If the sun gets brighter, we warm up. If a volcano blocks the sun, we cool down. If you take a continent and move it from the equator to the pole, the continent gets colder, and if you move the continent from the pole to the equator, the continent gets warmer. If you move the continent to block an ocean current, it affects the climate where the current used to flow. Many factors affect climate. There are also some factors that are very subtle and probably don’t matter much. When the earth’s magnetic field changed strength, the climate didn’t follow. We have records from 40,000 years ago that indicate that the magnetic field reached almost zero. That meant we were no longer as protected from cosmic rays. Those rays came streaming into the earth’s system, breaking atoms and creating radiocarbon and other things. But if there’s a cosmic ray effect, it must be very subtle because the climate largely or completely ignored these large changes in cosmic rays. Some factors clearly matter and others don’t. The meteorite that killed the dinosaurs put up a lot of dust, but other than that, we don’t see much evidence for changes in dust from space. It’s not an important factor. What we do see is a very tight linkage between CO2 and temperature over long time periods. It doesn’t matter if you look at the last century or the last 100,000 years or the last 100,000,000 years or the last billion years. You see a very tight link between CO2 and temperature. We’re going to explore that connection a little bit. The fact that CO2 warms is based on physics that we’ve understood for more than a century. The mere existence of a correlation between CO2 and temperature is not what’s driving us to believe that CO2 causes warming. But it gives us a test of our physical understanding, and we pass with flying colors. When we apply that understanding of physics to paleoclimate, the effects of CO2 explain much of what happened. Nothing else similarly explains all those things. So we’re pretty confident about our conclu-

sions. We always run into this absolutely fascinating question: to what extent is CO2 rising because it’s warmer, and to what extent is it warmer because CO2 is rising? Which is the chicken, which is the egg, and how are they related? We are reasonably confident that over time periods of centuries or millennia, warmer temperatures will raise CO2, which makes it still warmer. The CO2 can be an amplifier. Over time periods of a million years or longer, warmer temperatures tend to reduce CO2 levels in the air. It’s very funny; if it’s warmer in the short term, you get more CO2 in the air. But in the long term, you get less CO2 in the air. It shouldn’t be entirely surprising that there are processes that have different short-term and long-term effects. If I eat more, I’m going to gain weight. Except if I ate three or four jalapeños, I might have to run to the bathroom and I’d lose weight in the short term. If temperature rises in the short term, that likely raises CO2, and in the long term, it lowers CO2. Let’s walk through the processes that make this happen. A volcano spews CO2 and rocks. Then rain picks up CO2 from the air, making weakly acid rain. Acid rain breaks down the rocks, carrying the products to the ocean, where they get put into shells and subducted down into zones that feed volcanoes. Over millions of years, volcanoes release rock and CO2, which get recombined and then run down through the earth and back to feed the volcano again. How much acid rain is attacking the rocks is based on chemical reactions, which happen faster when it’s warmer. If you turn up the temperature, eventually the CO2 reacts with the rocks faster and that lowers CO2. And if you wait a million years, any CO2 we put up in the air will eventually be taken down by nature. If you’re thinking about a billion years of Earth’s history, we don’t matter and our CO2 doesn’t matter. So what’s the big deal? If you’re thinking about shorter time frames, then maybe we do matter. Nature tries to take down CO2 when it’s warmer. Yet we find that when CO2 was high in the past, it was warm: volcanoes were fighting this process because of slow changes in geologic processes. But the warming effect is very clear from history. Long term, it is not warmth that is raising CO2, it is CO2 that is raising warmth because the chemistry is such that nature is trying to remove CO2. Short term, we’re pretty sure that when you turn up the temperature, you get

more CO2, which turns up the temperature more. The best examples of this are the ice ages. Twenty thousand years ago, there were glaciers on Chicago and some places in New York. The ice ages were very clearly caused by features of Earth’s orbit. The orbit does not greatly affect the total amount of sunshine we get, but it moves sun around the planet, north to south, and summer to winter. When there was a lot of summer sun in Canada, the ice melted. When there was a little summer sun in Canada, the ice grew. What’s very odd about all this is that when ice grew in Canada because there was little summer sun, ice also grew in tropical glaciers, and in high mountains, and in Antarctica, and in New Zealand. It grew all over the world, even in places that were getting more sunshine. This is very strange behavior. You reduce Canada’s sun in the summer and the whole world gets colder—even places getting more sun. The only way we’ve succeeded in explaining this phenomenon is that when Canada gets little summer sun and the ice grows, CO2 falls. Canada’s sun can’t directly change CO2. But it can change ice, and that changes sea level, ocean currents, and other factors—and those factors change CO2. CO2 changes more slowly than some other things because of the chain reaction: sun affects something, which affects CO2. One of the somethings is the ocean’s temperature. If the ocean gets a little colder, it absorbs more CO2. If it warms up, CO2 comes out—just like warming up a Coke drives off fizz. Another factor is the amount of fertilizer. The ocean is blue, not green, because there isn’t enough fertilizer to grow a lot of plants. If there’s an ice age in Canada, a lot of dust containing fertilizer blows into the ocean. The dust grows more plants, which use CO2 from the surface ocean, which is basically in equilibrium with the atmosphere. So the plants are really using CO2 from the atmosphere as well. Plants then get eaten by animals, and animals poop, dropping fecal pellets into the deep ocean. CO2 is taken to the deep ocean if you fertilize with more dust. In addition, when the big ice sheet grows on Canada and changes temperature, it affects the direction of winds. Through a fairly interesting and complicated series of events, colder temperatures shift the winds around Antarctica. If the winds around Antarctica move north to blow across South America rather than south of South America, it changes mixing in the ocean. That changes the

ability of the CO2 that comes from worms eating the sinking poop to come back to the surface. In a cooling world, as the winds move onto South America, that tends to leave CO2 in the deep ocean rather than letting it out. Then sea ice grows, which makes it harder for the CO2 to get out. There are three or four more processes: it gets wonderfully complicated. But the bottom line is that the orbits cause changes in the ice in Canada, which causes other changes, which affect CO2. And then the whole world is affected by the CO2, including some places that react in the opposite way from what you would expect based on their sunshine. In the broad picture, physics says CO2 makes it warmer. When we look at history, a huge number of climate changes are directly and immediately explained by what we know about changing CO2. Theyâ&#x20AC;&#x2122;re not explained by anything else. In some cases, the CO2 drove it. A volcano added CO2 to the air, or we added CO2 to the air. In other cases, CO2 is responding to other changesâ&#x20AC;&#x201D;amplifying and globalizing those changes. So, a chicken lays an egg and an egg hatches a chicken. Sometimes the CO2 makes it warmer, which causes changes, and sometimes warmer temperatures affect the CO2, which causes other changes. These feedbacks really work. The history of climate confirms our physical understanding with very high confidence that more CO2 makes it warmer.

Questions and Answers Question: We see a very tight linkage between CO2 and temperature in the ice core record. Do scientists use that to infer a climate sensitivity? Answer: Yes, absolutely. Climate sensitivity refers to the question: if you were to double the amount of CO2 in the air, hold it constant, and let the climate catch up, how much would the world have warmed? Our understanding is that we expect about three degrees Celsius in the modern world. That is very close to what you get from the ice age cycling. The ice age was five to six degrees Celsius colder than today, globally averaged. Some of the difference is because the big ice sheets reflected more sunshine. Some of it is because a lot of dust blocked the sun. But that doesn’t explain nearly enough of the temperature change. CO2, with a little help from methane and nitrous oxide, explains the rest of it. If you model the ice sheets, the dust, the change in vegetation, the change in the sea level, and see what temperature change is left to be explained by CO2, you get three degrees Celsius for doubled CO2 with an uncertainty that’s about one degree. It’s a nice, tight constraint. So the climate sensitivity that the ice age implies agrees very well with the climate sensitivity that we get from our physical understanding today. But there’s a big asterisk here: that number is the result if you account for the dust, plants, and ice sheets. But the ice sheet would never have grown as big without help from CO2. So climate sensitivity on short time scales of a century or two agrees very well with what we’re expecting, but climate sensitivity on long time scales of 10,000 years is bigger than what we’re expecting. There’s little hope that the ice age makes things look better for the long future. And some say that the earth is more sensitive than we think. The total change in sunshine from the ice age to today is almost zero, and the world changed six degrees Celsius, so Earth is very clearly changing a lot without much forcing.

Question: What is your opinion about artificial iron fertilization? Is it a good option to increase the ocean’s carbon sink? Also, could you elaborate on your recent research on tipping points in climate change? Answer: Iron fertilization: it’s a beautiful idea. It makes you want to just sit there and smile! It’s very clear that in certain parts of the Southern Ocean and other places, if you dump iron in, you grow more plants. Presuming the plants get eaten so that you have a functioning ecosystem, CO2 will be removed from the surface ocean and the adjacent atmosphere. But it may take awhile for the ecosystem to start functioning so all that carbon will turn into poop and worms and whales that will sink. Just dumping in some iron and quitting may not do much. And if you’re really perturbing the ecosystem, it may never make a lot of difference. But beyond that, you can’t make an insane amount of carbon sink—not a huge amount. If you were to fertilize everything all the time and make lots of plants that get eaten by animals that sink, down below the decay of those plants, the oxygen gets used up. You’re not increasing the flux of oxygen that’s sinking. You’re just increasing the flux of things that can be respired by what’s living down deep. When you run out of oxygen, you start making more methane and nitrous oxide, which are more potent greenhouse gasses than CO2 in the modern world. If you get serious about ocean fertilization, you go a little distance and then you start losing again because anoxia is not a good thing: it can put out gasses that cause problems. I do not believe that you can make a large difference by doing this. You might make a small difference, but compared to how much CO2 we emit, it’s really hard to make a big impact. In terms of tipping points, running out of oxygen would be one interesting tipping point in the ocean which we wouldn’t like. The biggest one we’ve always worried about is the shutdown of the North Atlantic Current. We are cautiously optimistic that will not happen—that while we’re pushing in that direction, we’re not pushing hard enough. I put that one and several others in the insurance realm. You get in your car and you expect to

get stuck in traffic and to have lousy radio. The best thing that can happen is you have no traffic and great radio and the worst thing that can happen is that you get run over by a truck and you’re dead. What we’re expecting in climate change is traffic and bad radio. We’re hoping it’s even better than that. But there’s a slight chance that we trigger some really nasty instability tipping point and we get run over by a truck. The situation could be a little better, or could be a little worse, or could be a lot worse. But it won’t be a lot better. The opposite of too hot for us is too cold for us, and that’s not good either. Even if tipping points are very unlikely, we have to guard against them. In terms of driving, we buy the car that has side airbags, crumple zones, and antilock brakes. We put a huge effort into avoiding the unlikely but possible accident when it comes to driving. It’s an interesting question: given that a huge tipping point is unlikely but possible, is it relevant? Question: Climate models have suggested that the rapid warming of the Bølling-Allerød interstadial period was due to the resumption of the Atlantic meridional overturning circulation and a decrease in melt water in the North Atlantic. Could you expand on using this model as a proxy for predicting future climate change? Answer: In the modern world, during the middle of winter, there’s open water off of Norway in the Atlantic: it’s not frozen. Because of that, the air just above the water is warmer than freezing. So Norway gets snow like crazy but it doesn’t get really cold. (Manchester United plays soccer on Boxing Day because it doesn’t really get cold up there.) If the surface water in the North Atlantic off of Norway were fresher, in the modern climate, it would freeze in the winter. As you cool the water, it can do one of two things. It may get smaller and smaller until it sinks. Then warm water replaces it. The North Atlantic is salty enough now that it sinks, and if it were fresher, it would freeze. What we find in history through the ice ages is that whenever it got fresher, it tended to freeze and whenever it got saltier, it tended to sink. The difference in temperature around the North

Atlantic between sinking and freezing has been about ten degrees Celsius. It’s been a very big difference. When the North Atlantic froze, it pushed the equator for the climate (the spot on Earth where the hot air rises in the great tropical circulation) a little bit to the south. That shifted the location of the tropical circulations and weakened the monsoons in Asia. (There are a couple billion people in Asia waiting for rain from the monsoon.) If the North Atlantic freshened too much in the past, it dried up places where a billion or two people now live. That possibility is terrifying to me. When we came to understand that fresh in the past meant dry in the monsoon, we realized that we’re melting Greenland: we’re making it fresh. It scared the pants off of us. What’s happened since is that, quantitatively, we don’t seem to be melting Greenland fast enough to make the North Atlantic fresh enough that it would freeze in the winter until it gets so hot that it won’t freeze anyway. The Intergovernmental Panel on Climate Change (IPCC) recently gave at least a 90 percent confidence rating that we would dodge that bullet. But 90 percent is not 100. So we return to this interesting question of should you slow down because it’s insurance? It helps you avoid getting hit by the truck of a freezing North Atlantic that dries the monsoon. My take is that it’s unlikely that we will see any really abrupt events like the BøllingAllerød or Younger Dryas. But we can’t entirely, 100 percent, guarantee that it won’t happen. If you want to play it safe, then you slow down warming now so that you have less fresh water going into the North Atlantic, so you have less possibility of freezing in the winter and hurting the monsoon. Question: You have been quoted as saying that the ice in Greenland is melting about 100 years ahead of schedule. What is the latest science about the resulting sea level rise? Answer: Greenland is clearly going faster than we expected. But the things that have been getting headlines in Greenland eventually will have to slow down.

If you take an ice cube out of your drink and put it on the table, it’s going to melt, but it takes awhile. If you break it up with a hammer, it can melt a lot faster. Things that spread out the ice allow it to melt much faster. Right now, Greenland is dumping icebergs like crazy out of some of the glaciers in the deep fjords. Once it dumps enough icebergs, though, it pulls out of those deep fjords and then it can’t dump icebergs easily. It becomes the ice cube sitting on the table, melting. We think that will take centuries, not decades. The best science points to Greenland dumping ice and probably going away if we make it too warm—but not over decades. The big concern is still the West Antarctic ice sheet because it has the capability of raising sea level by about three or four meters just by dumping icebergs, without ever getting warm enough to melt on top. If the water it contacts gets warmer, it can potentially dump a lot of icebergs. As soon as it takes ice that’s not floating and throws it into the ocean, sea level rises. There are many circumstantial arguments about the ice sheets, but we still don’t have the accuracy of models that is needed for confident, precise projections. So there’s great uncertainty and a real worry that we may be putting a good bit more water into the ocean than we expected. There’s no assessed number. The IPCC’s last report projected a sea level rise of a foot or two feet in the century, plus whatever rise comes from weird behavior of the ice sheets: we just don’t know what that will be yet. A lot of people are projecting a meter sea level rise per century based on fairly fuzzy things. But there’s still a slight chance that it goes above that. We’re working on this really hard. I’ve got a couple papers in my inbox right now from students, post-docs, and faculty that relate to this question. But I don’t think I’ll be able to tell you in the next year or two what’s really going to happen. I don’t think we’re that good yet. Question: James Hansen and others have said that the last time the planet was hot, the temperature was about three degrees Celsius warmer and the sea level was 75 feet higher than now. Is that correct?

Answer: That’s probably on the high end. There are a lot of coral on a lot of islands that were in the ocean 130,000 years ago and are now sitting high and dry. We have pretty good evidence that sea level was higher then, and fairly good evidence that it involved a significant contribution of ice from both Greenland and Antarctica. The number that’s often floated is about six meters. Some of that difference comes from a different pattern of sunshine, some of it because it was a little bit warmer. But it’s not a huge difference in sea level from today. If you look farther in the past, there are indications that the CO2 levels that we’ll reach fairly soon were accompanied by even higher sea level—I think that’s the number you’re referencing. The science is still coming in on this, but I don’t think it’s astonishing that during the Pliocene, CO2 was probably at levels that we’re going to pass and sea level was at levels that would require all of Greenland, West Antarctica, and maybe a little bit of East Antarctica to be gone. The error bars are huge, but our current best estimate is that a small increase in CO2 equaled much higher sea levels. Question: Given the uncertainty of tipping points, how should they be addressed in the policy realm? Answer: I try very hard not to take policy positions because I have the remarkable good fortune of being asked for advice by policy makers on both sides of the aisle. If I were to take a particular policy position that certain lawmakers didn’t like, they might stop asking questions altogether. I see this happen a lot. But I think the best way to address this is through the lens of how to handle risk and insurance. The IPCC has produced an estimate of the challenges we face in the future. When you run that through economic models, the great majority say that humanity is better off dealing with the issue now, rather than ignoring it. There are uncertainties. But science is pretty clear that the uncertainties are mostly on the bad side. The warming might be a little less, a little more,

or a lot more. The warming on land is more than the warming in the ocean, so almost every human being on the planet will experience above average warming because we’re not living in the middle of the Pacific. There is the slight chance of going over tipping points, which would make the impacts much greater than we expect. Economic models say that you should act now to head off warming if you want to optimize the good. They indicate that we should develop resiliency now because the slight chance of really huge disasters does matter. It is economically sane and reasonable for people to take out insurance against disasters. The shape of the uncertainty curve for global warming impacts has a long tail on the bad side. Question: Lately, we have been hearing a lot about drought as a potential risk associated with climate. How do you reconcile that with the idea that we’re also experiencing more extreme weather events? Answer: This drives people crazy. If you tell people we expect both more floods and more droughts, they accuse you of contradicting yourself. But that’s what we expect. I grow tomatoes in the backyard—except the deer ate them this year, but normally I grow tomatoes. All winter, my ground is damp or frozen and in the summer, I get a huge thunderstorm that washes things out. Two weeks later, I’m watering the tomatoes again because the ground has dried out again. In a warmer, more summer-like world, you really do expect more flooding and more drought. This happens because, when conditions are right to make it rain, if the air is warmer, there’s more water in it and it can rain harder. When it quits raining, it dries out faster. There are changes in the pattern of circulation that have a tendency to expand the subtropical dry zones. So there’s a moderate probability that some fraction of the drought in Texas is caused by climate change. We can argue about that until the cows come home, but the models predict that from Texas through the Southwest and South, and near the Sahara and other places, we will see drying because of a warmer world expanding the

subtropics. Those places are seeing drying. Both because a warmer world creates more variability in the water system and because of changes in circulation patterns, we expect that where the rain falls, it can become more intense, but it will also dry out more afterward. The prediction of more floods and more droughts is already appearing in the data. Question: What concerns you most about climate change? Answer: We have isolated many rare and endangered species in national parks and little nature conservancy holdings. Humans have surrounded them. When the climate is changing and they need to move a thousand miles, how do they do it? Melting ice sheets make me pretty nervous. Poor people in hot places are already getting hurt and that situation will get worse. The global aggregate economy will do well for awhile because most of the economy is driven by wealthy people in colder places. They won’t get hurt initially. So what makes me nervous is that we’re endangering rare species and hurting poor populations, but the average guy doesn’t see it because it hasn’t started to affect him yet. Question: What advice would you give someone who is trying to move us beyond debates about subtle science to the question of what do we do about climate change? Answer: I think it’s important to separate the science from the policies. Once people see the science, they jump right to policy questions. But I think we need to make sure that physics is physics is physics. Then we can talk about policy. It’s going to take realizing that we are better off dealing with climate change now rather than waiting for absolutely solid science. Ultimately, there is money to be made here. There are happier people to be made here. Dealing with this problem can create jobs. But there are people who will lose their jobs—and they know who they are. The people who will gain jobs are students who don’t yet know what

kind of work they will do. If more jobs are created than are lost, but the people who get the new ones donâ&#x20AC;&#x2122;t know who they are and the people who lose the old ones do, thatâ&#x20AC;&#x2122;s a political issue. Ultimately, you can help people by getting started soon because then you can go slowly and avoid firing people. If you care about coal miners, you probably want to do something now. If you start now, you can spend 30 years making the transition and certain jobs can retire with their workers. If you wait 20 years just to get started, and the costs of the shifting climate become clearer, then economic change is likely to happen really fast. That means people in some industries will get fired.

About Richard Alley

Dr. Richard B. Alley is Evan Pugh Professor of Geosciences and Associate of the EMS Environment Institute at The Pennsylvania State University, University Park, Pennsylvania. There he teaches and conducts research on the paleoclimatic records, dynamics, and sedimentary deposits of large ice sheets, as a means of understanding the climate system and its history, and projecting future changes in climate and sea level. Dr. Alley has spent three field seasons in Antarctica and eight in Greenland. He was elected to the US National Academy of Sciences, and has received many awards, including the Tyler Prize, the Heinz Award, the Revelle Medal, and the Seligman Crystal. He was presenter for the recent three-hour PBS series Earth: The Operatorsâ&#x20AC;&#x2122; Manual, and wrote the related book. His book on abrupt climate change, The Two-Mile Time Machine, was the national Phi Beta Kappa Science Award winner for 2001. He has authored or coauthored more than 225 peer-reviewed publications.

About The National Climate Seminar a n d t h e B a r d C e n t e r f o r E n v i r o n m e n t a l Po l i c y

The National Climate Seminar is a twice-monthly national conference call with top climate scientists, policy makers, analysts, and communications experts. At the Bard Center for Environmental Policy, we believe that solutions to environmental challenges such as climate change must be tackled from an integrated perspective. Whether enrolled in the existing environmental policy track or the new climate science and policy degree, students are given rigorous scientific, economic, legal, and political training, and graduates enter their careers equipped with the knowledge and practical experience to create thoughtful and competent policy. Learning is enhanced by small class sizes, a close rapport between students and faculty, and important classroom discussions. The intensive, campus-based, first-year curricula allow students to synthesize information from a range of disciplines and sources. This classroom experience is strengthened by a 4â&#x20AC;&#x201C;6 month internship, providing students with valuable hands-on experience and facilitating entry into the job market. Graduates enjoy successful careers in nonprofit, government, and private sectors at local, regional, national, and international levels. At Bard College, a four-year residential college of the liberal arts and sciences, Bard CEP graduates enjoy the peaceful campus environment, with full access to Bardâ&#x20AC;&#x2122;s state-of-the-art resources and facilities, while being nestled in the beautiful and historic Hudson River Valley.

Yo u m a y a l s o b e i n t e r e s t e d i n o t h e r s e m i n a r s i n The National Climate Seminar Series:

Hot: Living Through the Next Fifty Years on Earth by Mark Hertsgaard (978-1-61091-414-7) Climate Capitalism by L. Hunter Lovins (978-1-61091-415-4) Smarter Planet? IBMâ&#x20AC;&#x2122;s Climate Solutions by Sharon Nunes (978-1-61091-416-1) Global Warming, Politics, and the Media by David Roberts (978-1-61091-417-8) Up-to-date information on the series can be found here.

I s l a n d Pr e s s

Board of Directors

Decker Anstrom (Chair) Board of Directors Comcast Corporation Katie Dolan (Vice-Chair) Conservationist Pamela B. Murphy (Treasurer) Carolyn Peachey (Secretary) President Campbell, Peachey & Associates ________________ Stephen Badger Board Member Mars, Inc. Margot Paul Ernst New York, New York Russell B. Faucett CEO and Chief Investment Officer, Barrington Wilshire LLC Merloyd Ludington Lawrence Merloyd Lawrence, Inc. and Perseus Books William H. Meadows President The Wilderness Society Drummond Pike Founder, Tides Principal, Equilibrium Capital Alexis G. Sant Managing Director

Persimmon Tree Capital Charles C. Savitt President Island Press Susan E. Sechler President TransFarm Africa Victor M. Sher, Esq. Principal Sher Leff LLP Sarah Slusser Executive Vice President GeoGlobal Energy LLC Diana Wall, Ph.D. Director, School of Global Environmental Sustainability and Professor of Biology Colorado State University Wren Wirth President Winslow Foundation

A b o u t I s l a n d Pr e s s

Since 1984, the nonprofit Island Press has been stimulating, shaping, and communicating the ideas that are essential for solving environmental problems worldwide. With more than 800 titles in print and some 40 new releases each year, we are the nation’s leading publisher on environmental issues. We identify innovative thinkers and emerging trends in the environmental field. We work with worldrenowned experts and authors to develop cross-disciplinary solutions to environmental challenges. Island Press designs and implements coordinated book publication campaigns in order to communicate our critical messages in print, in person, and online using the latest technologies, programs, and the media. Our goal: to reach targeted audiences—scientists, policymakers, environmental advocates, the media, and concerned citizens—who can and will take action to protect the plants and animals that enrich our world, the ecosystems we need to survive, the water we drink, and the air we breathe. Island Press gratefully acknowledges the support of its work by the Agua Fund, Inc., The Margaret A. Cargill Foundation, Betsy and Jesse Fink Foundation, The William and Flora Hewlett Foundation, The Kresge Foundation, The Forrest and Frances Lattner Foundation, The Andrew W. Mellon Foundation, The Curtis and Edith Munson Foundation, The Overbrook Foundation, The David and Lucile Packard Foundation, The Summit Foundation, Trust for Architectural Easements, The Winslow Foundation, and other generous donors. The opinions expressed in this book are those of the author(s) and do not necessarily reflect the views of our donors.