hydrosphere.html (Atmosphere  Biosphere  Dead Biosphere) THE REGULATION OF CARBON DIOXIDE AND CLIMATE: GAIA OR GEOCHEMISTRY* J. E. LOVELOCK Department of Cybernetics, University of Reading, Reading, U.K. and A. J. WATSON Marine Biological Association, Citadel Hill, Plymouth, U.K. Gaia hypothesis originally proposed by J.E. Lovelock and Lynn Margulis in 1974.

View of the Earth as seen by the Apollo 17 crew traveling toward the moon. This translunar coast photograph extends from the Mediterranean Sea area to the Antarctica south polar ice cap. This is the first time the Apollo trajectory made it possible to photograph the south polar ice cap. Note the heavy cloud cover in the southern hemisphere. Almost the entire coastline of Africa is clearly visible. The Arabian Peninsula can be seen at the northeastern edge of Africa. The large island off the coast of Africa is the Malagasy Republic. The Asian mainland is on the horizon toward the northeast.

Water, water every where And all the boards did shrink; Water, water every where, Ne any drop to drink. The Rhyme of the Ancient Mariner Samuel Taylor Coleridge

Salt water Oceans – (contain ~97% of all water on earth; also responsible for weather, redistribution of energy) Fresh water Polar ice caps, glaciers Lakes, streams, ground water, soil water Brackish water Water whose salinity is intermediate between that of fresh water and salt water Types of Water in the Hydrosphere

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water table Zone of saturation (or ground water zone) hydrosphere/hydrosphere.html

“On the one hand, the fundamental fear of food shortages encourages ever greater use of water resources for agriculture. On the other, there is a need to divert water from irrigated food production to other users and to protect the resource and the ecosystem. Many believe this conflict is one of the most critical problems to be tackled in the early 21st century”. From the Framework for Action exercise of the Global Water Partnership (GWP, FFA, 2000, p58), cited in “Balancing Water Uses: Water for Food and Water for Nature.” Frank R. Rijsberman and David Molden, International Conference on Freshwater, Bonn, Germany, The Green Revolution -- based on modern, high yielding plant varieties, requiring high inputs of fertilizer and water -- has led to increases in world food production at a pace that outstripped population growth. Food prices have declined markedly. Increased water use in irrigated agriculture has benefited farmers 2 and the poor. 3 But increased water and chemical use that fueled the Green Revolution has contributed to environmental degradation, and threatened the resource base upon which we depend for food and livelihoods.