Water Cycle of the Earth
About 70% of the Earth's surface is covered by water. The atmosphere, groundwater, rivers, oceans, and ice masses constantly exchange water. In the process its state also changes (from liquid to gas, for example).
During evaporation, water becomes water vapor. When the sun heats a water surface, the water molecules accelerate until they are so fast that they escape into the air as a gas. …many of which are transported to land masses by winds.
Precip itation
Rain that falls on leaves and needles is first stored in the forest canopy.
Only when more rain falls than the canopy can absorb does the water seep into the forest floor.
Clouds, which form from the rising water vapor, provide rain replenishment. of the precipitation in a forest returns to the atmosphere.
Water absorbed by the roots is partly transpired through the crown. Some water evaporates directly from the canopy.
Seepage water
Permafrost
Sources: Markart & Kohl (2009), Perlmann et al. (2019), USGS (2019), Zimmermann et al. (2008) Groundwater
Saltwater
The Seas of the Earth
5 basins form the global ocean: the Atlantic, Pacific, Indian, Arctic, and Southern Oceans. In addition, there are larger and smaller seas that are enclosed or bordered by land masses, such as the European Mediterranean or the Black Sea.
3.5% of the weight of seawater consists of dissolved salt. The salt content is lower at the equator and the poles than in the mid-latitudes. Only 9%
Approx. 91% of the estimated 2 million animal and plant species in the oceans are unexplored and unknown.
125 m
Approx.
70 % of the Earth's surface is covered by oceans. higher than the sea level during the last ice age.
4 x more oxygen-depleted dead zones. Global warming has reduced the oxygen content of the oceans by 40% since 1970.
11,000 m is the deepest part of the ocean, the Mariana Trench in the Pacific.
Only 20% of the seabed has been explored and mapped in detail with echo sounders.
of all marine species are identified.
North Pole…
3200 m thickness
148 Gt of ice mass is lost from the Antarctic Ice Sheet per year. Ø 2010-2019
243 Gt of ice mass is lost from the Greenland Ice Sheet per year on average.
–18 °C the annual average temperature in the Arctic (on land).
Ice volume in Greenland –50 °C average temperature at the South Pole.
3 M km3
8 states
are Arctic neighbours. The territorial claims are governed by the law of the sea, but are disputed.
4 M
Ice volume in the Antarctic 26 M km3
Southern
Ocean
Antarctica is surrounded by the sea. The Antarctic Treaty determines the peaceful use of the South Pole.
1000–4000
researchers live temporarily in Antarctica.
4897 m
Rivers of Waste Dirty Groundwater in the US
Tire wear on asphalt in Europe produces an estimated 700,000 million tons of microplastics annually.
As many as 700,000 microplastic fibers can be released into wastewater each laundry cycle. Each year in Europe, about 3800 tons of microplastic from cosmetics and personal care products is released into the environment.
Globally, 500,000 tons of microfibers are released into the ocean from washing machines each year. This accounts for at least 35% of all ocean microplastic pollution.
In Europe, it is estimated that 570,000 tons of microplastic granules enter the oceans each year, for example through accidental spillage or through treated industrial wastewater discharged into rivers.
Industrialized nations vs. developing nations
Several major cities discharge their wastewater into the sea, including Athens, Barcelona, Brighton, and Cork.
In India, 80% of wastewater is discharged into rivers without any form of treatment.
Waste is deposited into illegal dumpsites, where it washes into river systems during heavy rains and floods.
Illegal gold panning dumps dangerous chemicals such as mercury, a neurotoxin, into rivers in Asia, Africa, and Latin America.
Approximately 7000 different chemicals, including persistent organic pollutants (POPs), are used in textile dyeing processes.
Agricultural fertilizers over-fertilize coastal areas and create oxygen depletion zones, especially near river deltas.
Sources: Bexfield et al. (2021), DeSimone et al. (2015), USGS (2019)
41 % of 1200 wells tested were contaminated with pesticides from agriculture. More than
1 in 5 groundwater samples were a concern for human health.
140 million people, nearly half of the population rely on groundwater for drinking water.
Protect your groundwater!
• Buy organic products (for pollutant-free soils in agriculture).
• Use organic fertiliser in your garden.
• Dispose of paints, batteries and medicines properly.
• Wash cars only in car washes (where the water is recycled).
• Use sand instead of road salt in winter.
• Lay water-permeable material on paths and terraces.
• Use a rainwater cistern.
• Water the garden only in the morning or evening.
• Save water in the household. 9-14
Plants
Life's Basic Building Blocks
400,000 plant species have been identified worldwide. About 2000 new species are discovered every year.
Plants produce the oxygen we breathe and form the basis of our food and medicine. We use them for everyday things like clothing (cotton, hemp), building materials (wood, straw) and biofuels (maize, sugar cane). They also have spiritual and cultural significance for many people.
Sunlight is the energy source for photosynthesis
A plant [from Latin planta = seedling, young plant] is a living organism that grows in the soil, in water, or on other plants. A plant makes its food from sunlight and consists mainly of roots, stems, and leaves. 94% of all plants have flowers.
44 % of all plants are threatened with extinction.
CO2 intake
With the chemical energy, the leaf cell converts the absorbed carbon dioxide and water into carbohydrates (sugar).
Oxygen release
Sugar transport
Thylakoids form stacks, called grana, filled with the light-absorbing pigment chlorophyll, which generates chemical energy from light energy.
4-8 μm
Leaf veins transport water and nutrients
Chloroplasts (cut open) are green cell organelles consisting of very complex membrane structures called thylakoids.
Leaf cells perform photosynthesis
Photosynthesis
Leaves absorb carbon dioxide and water and convert it into sugar using solar energy. This is the basic building block of life. Microscopic organelles in leaf cells, containing the pigment chlorophyll, are responsible for the chemical conversion. A 100-year-old oak tree, for example, provides enough oxygen for around 11 people every year.
Sources: Antonelli et al. (2020), BD (2017), Wald und Holz NRW (2022), Spektrum (2001)
Nucleus
Vacuole (filled with cell sap)
Chloroplasts
Loss of Forest Dwellers
An estimated
41% fewer species live in degraded tropical rainforests compared to intact forests.
Sources: Alroy (2017), IUCN (2020)
Koala
Proboscis monkey
Tapanuli orangutan
Borneo dwarf elephant Tiger
Giant panda
White-breasted toucan
Ring-tailed lemur
Peleng tarsier
Java rhino
Eastern gorilla
Hyacinth macaw
Tasmanian tiger
Okinawa woodpecker
grasshopper
March's palm pit viper
ornament bird spider
Rusty-spotted bumblebee
Collar sloth
Golden lion tamarin