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Why climate matters |
It's happening now
Most of the global warming over the last 50 years has been caused by human activities, primarily burning fossil fuels that release carbon dioxide - a greenhouse gas that traps the sun’s heat and warms the Earth. Greenhouse gases occur naturally in our atmosphere, without them the Earth would be too cold for life to exist. However, since the industrial revolution, our activities have vastly increased the quantities of greenhouse gases in the atmosphere: carbon dioxide concentrations have risen by more than 30% and methane by more than 150%. What is happening?Climate change is already occurring. Globally, the warmest recorded decade was the 1990s and all the 10 warmest years have been since 1990, including every year since 1997. Higher temperatures have affected physical and biological systems in many ways, including: shrinkage of glaciers, 40% thinning of Arctic sea ice, more frequent, persistent and intense El Nino events, poleward and altitudinal shifts of plant and animal ranges, as well as declines in some plant and animal populations. Coral reefs are highly sensitive to temperature changes in the seas. They have reacted dramatically to El Niño periods, as in 1998 when corals were bleached, and died, on a wide scale. Further climate change could condemn most of the world’s beautiful and vulnerable coral reefs to history. Feeling the impacts of climate changePeople the world over are already feeling the impacts of climate change – from increased flooding and droughts in some of the world’s poorest regions to right here at home. Future prospects are very serious, even with little further change in the climate. Climate change and water shortage will affect the success of food crops, leading to food shortages in poorer countries, especially Africa. Countries the world over will face increased levels of disease and natural disasters. It is ironic that the leaders of the world’s richest nations at the July 2005 G8 Summit failed to agree meaningful plans to tackle climate change. Aiding Africa was the other major item on the agenda, but climate change could be devastating for Africa in the long term. Catastophic consequences - looking to the futureThe UN's Intergovernmental Panel on Climate Change (IPCC) has developed different scenarios for human development, each of which results in different levels of greenhouse gas emissions. The scenarios show increases in global average surface temperature of between 1.4°C by 2100, for the lowest emission scenario, to 5.8°C for the highest. The most recent research indicates that the higher emission scenarios may lead to higher temperature rises than previously thought, perhaps much higher at over 10°C, whilst the lower temperature rises seem less likely. The high emission futures would have catastrophic consequences for both people and wildlife. For comparison the difference between the highest and lowest average temperatures between a major Ice Age and warm 'interglacial' period is between 4-5°C. 'Disintegration of the West Antarctic Ice Sheet or melting of the Greenland Ice Sheet could raise global sea level by more than 3m, probably much more.' A temperature rise of 6°C, from our present interglacial period does not bear thinking about. This could result in slowing or shifting of the North Atlantic Ocean circulation which would dramatically reduce temperatures in North-western Europe to those of Hudson Bay in Canada. Disintegration of the West Antarctic Ice Sheet or melting of the Greenland Ice Sheet could raise global sea level by more than 3m, probably much more. Slowing or shifting of the North Atlantic Ocean circulation could dramatically reduce temperatures in North-western Europe. Disintegration of the West Antarctic Ice Sheet or melting of the Greenland Ice Sheet could raise global sea level by 3m or more. The likehood of such changes is not known and is probably very low but is expected to increase with the rate, magnitude and duration of climate change. We can prevent the worstWhatever action we take, some climate change impacts will inevitably occur. Even if we cut drastically global emissions now, the global average temperature will continue to rise to more than 1°C above pre-industrial levels. However, we can avoid some of the worst effects of climate change if we limit the global average temperature rise to less that 2°C above pre-industrial levels. We cannot now prevent the earth from warming by more than 1°C, whatever action we take. However, top climate scientists agree: we can avoid some of the worst effects of climate change if we limit the global average temperature rise to less that 2°C above pre-industrial levels. This will mean developed countries like the UK cutting emissions by 60 to 80% by the middle of this century. We can do this if, collectively, we embrace clean technologies and truly green ways of living. |
Saltmarsh at Wallasea Island - RSPB Images - Ben Hall (rspb-images.com, Ref: 1019670)
Puffin calling, Isle of May National Nature reserve - Andy Hay (rspb-images.com, Ref: 1009554 )
Micro turbine - Ray Kennedy (rspb-images.com, Ref: 1020726)
Bird illustrations by Mike Langman (RSPB)