The earth's ecosystem is an incredibly diverse web of interrelationships and dependencies that has evolved over millennia. Rapid climate change associated with global warming threatens to undermine this balance by introducing new stress to the system at a pace that far outstrips evolutionary adaptation. In practical terms any living thing that is dependent for survival on the type of climate they currently inhabit may well be faced with a stark choice between migration or extinction. The poignant plight of the Polar bear struggling to survive as its habitat melts away is just one of many creatures with no where to go. If we manage to control emissions at present rates estimates still place rates of extinction among animals and plants as high as 37% by 2050, any increase could take this figure as high as 50%. Even if we were able to accept this ecological tragedy, the implications for the survival of mankind are equally profound.
Our ability to feed ourselves is intimately dependent on the climate. As the earth warms a disproportionate impact will be felt in many of the poorest countries, where drought will afflict agricultural production. Crops that once flourished will fail and our capacity to produce food will decrease bringing with it the likelihood of famine.
Although more northerly regions may benefit from a longer growing season, they will also play host to some unwelcome climate migrants. Diseases like malaria and dengue fever once confined to the tropics are already spreading northwards as mosquitoes follow the more temperate climate. Agricultural pest are also on the move, leading to a potentially greater dependency on polluting pesticides.
Although it is difficult to gather data, the oceans too are threatened by climate change. Spectacular coral reefs, are particularly sensitive to temperature rises and have been decimated, with more than a quarter already destroyed. The tiniest marine plants, photoplankton and zooplankton die off if the water becomes too warm. These creature are the staple food of many species of fish and their absence can decimate fisheries. These delicate food chains, easily disrupted by temperature rises could well have a potentially catastrophic effect on our ability to feed an ever growing population.
