There are choices that need to be made if dangerous climate change is to be avoided in the 21st century. Previous reports from the Intergovernmental Panel on Climate Change (IPCC) have confirmed that the influence of human activities on the climate is unambiguous, and that climate change will have a major impact on human activities and ecosystems. Its third report, published yesterday, sets out the huge challenge that needs to be addressed by policymakers.The evidence is clear: sticking to business as usual will lead to temperature rises of three to five degrees above pre-industrial levels.
