So much information surrounds the United Kingdom Climate Change Bill, it is sometimes difficult to retain a clear picture of what is going on. The Bill was first published on 13 March 2007, as a draft law aimed at moving the Uk to a low-carbon economy and society. Its key component is a mandatory 60% cut in the UK's carbon emissions by 2050, with intermediary targets of between 26 and 32% by 2020. These targets, quite crucially according to some, exclude international aviation and shipping.

If approved, the UK will become the first country to set such a long-range, significant and binding carbon reduction target into law. To maintain progress, a national "carbon budget" would be set every five years, and government ministers would be required to provide a progress report each year, instead of require year-on-year carbon emission reductions.

The Bill's 60% target was adopted based on the recommendation of the Royal Commissions on Environmental Pollution, made in their June 2000 report Energy - The Changing Environment. If adapted by other countries too, a 60% cut by 2050 was thought likely to limit atmospheric carbon dioxide concentrations to no more than 550 parts per million which, it was generally thought at the time, would probably prevent global temperatures from rising by more than 2 degrees centigrade (3.6 degrees fahrenheit) and so avoid the most serious consequences of global warming.

It is worth noting, however, that the Royal Commission's figures were based on a June 1996 decision of the EU Council of Ministers to limit emissions to 550 ppm, contained in their Community Strategy on Climate Change, which was in turn based on the 1995 IPCC Second Assesment Report, which first mentioned the 550ppm figure. One scientific assessment at the 2005 international Avoiding Dangerous Climate Change conference concluded, among other things, that stabilisation would have to be achieved below 400ppm to give a relatively high certainty of not exceeding 2 degrees centigrade.

At the current rate of increase, greenhouse gas concentrations are likely to reach 550ppm by around 2091. Because of this, environmental organisations have criticised the 60% target as being insufficiently ambitious, and tend to demand cuts of between 80% and 100%. The exclusion of aviation and shipping emissions, combined with forecasts for growth in that area, also means the net effect of the bill would in real terms only be a 35-50% total cut on 1990 levels by 2050.

Environmental Groups

Friends of the Earth's Big Ask Campaign, probably the biggest single-issue campaign devoted to the bill, demands legally binding targets for a reduction of at least 3% a year, amounting to a total cut of 80% by 2050.