According to the ecologist magazine, Climate change is going to cause us severe problems unless drastic changes are made NOW and even then it’s a case of damage limitation, not avoidance. The article isn't available on-line (or else it is but i cant find it) but some of its main points are:
1. If CO2 emissions remain as they currently are, no increase from 375 parts per million of the atmosphere, then global temperatures will rise by 1 degree centigrade above what we have already experienced (.6 of a degree) This will lead to the probable melting of all sea ice and glaciers over the next 80 years and cause an increase of floods droughts heat waves violent storms and a redistribution of rainfall, thereby affecting agriculture.
2. If we manage to curb the increase to only 550 parts per million, double pre-industrial levels, global temperatures would rise 2 degrees over the next 100 years according to the IPCC. This would be on the very edge of what the planet could possible manage without massively severe problems. Nonetheless, sea levels would rise up to a foot or more as the water expands due to the extra heat and the ice caps melt further. Increased rainfall over Siberia would lead to an increase in cold fresh water into the Arctic Circle, which would curb the Gulf Stream with very bad effects for northern Europe.
3. If Energy use continues to grow at its current rate we will have 4 times the level of greenhouse Gasses when compared to pre-industrial times. The UK Met Office Hadly Center predicts a catastrophic 8-degree increase in temperatures. Global temperatures would then be at a level not seen for 40 million years when the planet had no permanent polar ice sheets and ocean levels were 12 metres higher than they are now. Costal cities would be lost, as would most of the world’s agricultural land and Violent storms would be regular occurrences due to the huge amount of extra solar energy trapped within our atmosphere. Survival for most of the population would be impossible
http://www.met-office.gov.uk/resear...pubs/brochures/
4. There are neglected variables. These statistics look only at the effect of greenhouse gases on their own, but as the temperatures rise and the atmospheric conditions change, there will be a warming of Soil and vegetation. This will affect the balance between photosynthasis and respiration. If respiration increases over photosynthasis then the forests and vegitation will stop acting as carbon dioxide sinks and become net contributors to the greenhouse gases thereby accelerating global warming. The Hadly center after taking these factors into consideration predicts that the IPCC (Intergovernmental Panel on Climate Change) predictions are actually conservative and that the climate changes might actually be much worse