Climate change is the greatest environmental challenge facing the world today. Rising global temperatures will bring changes in weather patterns, rising sea levels and increased frequency and intensity of extreme weather. The effects of this changing weather are already being felt around the world, but particularly in developing countries.

And it can only get worse, unless we act decisively and comprehensively to tackle the root cause of climate change; namely our burning of ever increasing amount of fossil fuels. When we burn fossil fuels - oil, coal and gas - carbon dioxide (CO2) is released into the atmosphere. The atmosphere is pretty thin and carbon dioxide¹ in the air acts like the glass of a greenhouse: it lets ‘short-wave’ sunlight in, but doesn’t let all the ‘long-wave’ heat energy back out: the trapped heat keeps our planet warm.

If you have any doubts about the extent to which we are responsible for rising global temperatures, please refer to The Royal Society publication: Climate Change Controversies: a simple guide.

Scientific opinion varies on how long we have in which to make the drastic cuts - in carbon dioxide and other greenhouse gas - emissions needed to first halt and then reverse the global temperature rise, before we go beyond the “tipping point”. Some, such as Nasa scientist James Hanson, believe we have less than 10 years. The strong concensus of the world's scientists however, is that we must act, and act decisively, both to reduce the demand for burning fossil fuels and to find alternative low carbon sources of energy to provide both heat and power for our buildings, as well as fuel for our vehicles.

The UK energy sector accounts for the largest proportion of the UK’s carbon dioxide emissions which is why the UK Government’s programme for reducing carbon emissions has focussed predominantly on encouraging the development of alternative sources of energy through the renewable order (RO).

See http://www.defra.gov.uk/environment/statistics/globatmos/gagccukem.htm for a chart showing the breakdown of the main sources of CO2 emissions.

¹ Carbon dioxide is the main man-made contributor to global warming. The UK contributes about 2 per cent to global man-made emissions, which, according to the IPCC, were estimated to be 38 billion tonnes carbon dioxide in 2004. Carbon dioxide accounted for about 85 per cent of the UK’s man-made greenhouse gas emissions in 2006. (Source: Defra website)