Climate Change

What is Climate Change?

The temperature of the earth is determined by the balance between energy from the sun in the form of sunlight, and energy constantly re-radiated from the earth to space. Sunlight warms the earth's surface which in turn warms the atmosphere by convection and the emission of infra-red radiation, which is absorbed by certain gases - the greenhouse gases. These return some infra-red radiation back to the surface thereby warming the surface further. A comparison is often made with the effect of a greenhouse which allows sunshine in through clear glass or plastic that in turn stops the heat inside from escaping, hence the term 'greenhouse effect'.

UK Climate Changes

Our climate is already changing. 1998 was the single warmest year in the 142 year global instrumental record, 2000 was one of the warmest years in Britain since records began, and in January 2003 the temperatures in Aberdeenshire rose to 18.3°C equalling the warmest January on record. The 10th August 2003 was the hottest day ever recorded in Britain.

It is predicted that, on average, summers will become hotter and drier with winters becoming milder and wetter. There will also be more extreme climate events - very hot days and intense downpours of rain. Sea levels will continue to rise increasing the risk of coastal flooding erosion and current extremes of high water levels will occur more frequently. The number of storms crossing the UK in winter could also increase.

The main effects of climate change in the UK have been predicted to continue and have been summarised as:

• More hot, dry summers and increased winter rainfall.
• Higher average wind speeds and increased storm frequency and damage.
• Greater seasonal variation in river flows.
• Increased pubic and agricultural demand for water.
• Rises in sea level of about 0.5 centimetres annually.
• Increased flooding and erosion in coastal zones.
• An increase in timber yield in the north of the UK.
• Lower crop yields in the south-east of the UK.
• A northward shift of natural habitats of 50-80 centimetres every decade.
• Increased evidence of certain infectious diseases.
• A reduction in air quality in the summer months.

Action to Mitigate the Effects

It is now accepted that some of the changes that have taken place and are predicted are irreversible, however that does not mean that action should not be taken to reduce the potential effects.

Experiments using global climate models show that when we reduce emissions of carbon dioxide, we reduce the rate of rise of average global temperatures and so lessen the rate and impacts of climate change. We can therefore slow the rate of warming by changing our behaviour.