"if we continue as we are, global mean temperature would increase by 0.3% per decade (within a range of 0.2 to 0.4 degrees); this is greater than the world has ever seen over the past 10,000 years. Global mean temperature over the next century would become higher than at any time over the last 150,000 years; sea level would rise by 6cm per decade (within a range of 3-10cm per decade) over the next century, 3 to 6 times the rate seen over the last 100 years".

The Department of Environment, Transport and the Regions has re-emphasised these concerns in a recent publication concerning climate change where it states that:

"Global warming is no longer a theory. Since the 1970s, the world has warmed by about 0.15oC per decade, and 1998 was the warmest year on record. In England, four of the five warmest years in the 340-year record occurred in the last decade. These are startling statistics. The clear message from the scientific community is that this warming is due, at least in part, to the increasing concentrations of greenhouse gases in the atmosphere."

On 21 January 2001, the IPCC issued a Summary for Policymakers which describes the current state of understanding of the climate system and provides estimates of its projected future evolution and their uncertainties. This report indicates that the average global surface temperature is projected to increase by 1.4 to 5.8OC, between 0.4 and 2.3OC higher than previously predicted. Whilst there has been substantial debate about the cause of climate changes that have occurred during the last part of the 20th Century, more refined modelling techniques confirm that recent climate changes, especially over the last few decades, are almost entirely caused by human activity, particularly in the emission of long-lived greenhouse gases such as CO2 arising from the burning of fossil fuels.

The English Nature report "SSSI’s in England at risk from acid rain" (Biset and Framer, English Nature report No. 15, 1993) considered the impact of sulphur deposition on SSSI’s in England and concluded that:

..."even if the EC Large Combustion Plant Directive were to be implemented in full, 600 SSSI’s were at risk from continued acidification".

These sites represented 26% of the total land area designated SSSI in 1993

Hence the environmental challenge posed by the production of greenhouse gases led to an international response, which was first initiated by the World Commission on Environment and Development meeting in 1983, and subsequently addressed at the Earth Summit 1992. Several Conventions arose from these meetings, including the United Nations Framework Convention on Climate Change and more recently the Kyoto Protocol. The UK response has been to introduce policies and legislation to address global warming and provide mechanisms for the introduction and enforcement of international conventions to which it is a signatory.

Renewable energy generation is now posited as a solution to global warming as it does not, generally, lead to the creation of greenhouse gases. Forms of renewable energy, such as wind, hydro, biomass and solar, are clean technologies that are encouraged to combat global warming. In Europe, guidance on promoting green energy and combating global warming is found in the European Commission’s Green Paper. In the UK, any proposals for the development of RE have to accord with the planning system. Therefore specific guidance on planning for such developments has been prepared. This guidance is contained in Planning Policy Guidance 22 (PPG22) for England, Planning Guidance Wales, and National Planning Policy Guidance 6 (NPPG6) for Scotland. This guidance is further supplemented in more detail for Wales in Technical Advice Note 8 (TAN8) and by Planning Advice Note 45 (PAN45) in Scotland.

Benefits of RE generation