I like the conceptof Gaia, the Living Earth. I especially love it because it offers a way to seeour world as a living being without appeal to any mystical explanation. I likebecause it shows our world as it really is: alive and fragile, susceptible to poisonsbut with defense mechanisms. Gaia has its "immune system" and will doeverything possible to stay healthy.One of its manydefense mechanisms is temperature control. This system is complex, butfascinating. One of the tools for this control is the polar and mountainglacier. Water is a fascinating substance. One of its many properties is itshigh thermal capacity. The water can contain five times more heat thanaluminum, 10 times longer than steel, and twice the capacity of the ice.Furthermore, while 4180 Joules are required to increase in 1oC (2oF) an amountof 1 kg water (more than 2 pounds), 334,000 Joules are necessary to melt thesame amount of ice at 0C (32oF). Therefore melting ice is difficult. Ifproperly packaged, the ice may not melt for many years. Therefore, a largeamount of energy can be absorbed by ice. Additionally, the ices clear surface reflectsback to space most of the energy coming from the Sun Polar caps are ourair-conditioning system.One of thearguments used by critics of global warming is precisely the fact that, inrecent years, the climate apparently shows a tendency to revert the trend ofwarming, showing severe winters both in the north and south hemisphere.Interestingly, during this time of stringent winters, the glaciers melting rateshowed above average speed. This is no coincidence. In fact, this melting is apart of Earths temperature control mechanism, because each kilogram of meltedice removes from the environment a lot of energy. However, this is no reasonfor us to be carefree. The control mechanism is working, but is being pushed tothe limit. This is because as the ice melts, there is a darkening of thesurface of the earth with a consequent increase in absorption of solar heat,which melts the new masses of ice.Our body has alsoa temperature control mechanisms. When our body is too hot, it starts thesweating process. Some water in our body is released through the skin pores. Watersevaporation cools our skin. This occurs because the energy required toevaporate the water is greater than that necessary to melt the ice (2,260,000Joules per Kg) Body heat is used to evaporate the water, making it colder in theprocess. In some situations, this control can fail. If a person stay for long periodsunder hot sun, the perspirations water evaporates at a much higher rate, dueto suns heat. Virtually no body heat will be used in the process and theperson will eventually become strongly dehydrated. This process is known assunstroke. One of the symptoms of heat stroke is high fever. As a defensemechanism against stroke, people adopt defensive behaviors, such as drinkingplenty of water and seek a shady spot. One consequence of heatstroke is burnsskin, which among other disorders, triggers an inflammatory process and impairsthe ability of the skin to perspire, worsening the symptoms.Similarly, theEarth is suffering heatstroke. But unlike a careless sunbather who abuses thesun, the Earth is in this