Climate changes are occurring in every region and globally, according to the latest Intergovernmental Panel on Climate Change report. As the world’s latest and most rigorous scientific assessment of the physical basis of climate change, the report defines changes that are unprecedented in thousands if not hundreds of thousands of years. It emphasizes that there is still time to act, but it must happen immediately. Limiting climate change demands strong and sustained reductions in greenhouse gas emissions from human activities such as burning fossil fuels. Press releaseSecretary-General’s statement.