Climate change is the increase in the average temperature of the Earth caused in the main by the increase in emissions of greenhouse gases. Temperatures have risen by nearly 0.74 degrees celsius in the last century with climate model projections predicting a rise in the 21st century of 1.1 - 6.4 degrees. The large range being down to the big unknown – greenhouse gas emissions.
Why is climate change a problem?
You could be forgiven as you step out of your house on a cold winter morning for thinking "is it such a bad thing"? Well I'm afraid it is and although a few degrees may not seem significant the resulting rise in sea levels is very significant indeed -- and not only for those living in low lying land such as the Norfolk Fens or The Netherlands. Sea levels have risen in the past century by just under 2 mm but the rate of increase in recent years between 2.8 and 3.1 mm a year up to 2003. The sea level rise due to climate change is a mixture of ice melt from the poles and as water itself warms it expands in volume through what is referred to as thermal expansion.
Apart from reclaiming low lying land through rising sea levels, climate change will also affect precipitation patterns, bring about more extreme weather conditions, bring expansion of deserts and retraction of the ice sheets and glaciers, changes in agricultural yields as a result in temperature and precipitation changes and risk further the demise of rain forests.
How the world will deal with climate change is the focus of much debate and the talks in December 2009 at Copenhagen where the world needs to decide upon a plan post-2012 when the Kyoto protocol ceases are critical.
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