The most authoritative report on climate change to date will be released tomorrow in Paris, France, and is expected to warn of rising global sea levels and temperatures. Earth observation from space plays an invaluable role in helping scientists advance our understanding of climate change and capability to model its evolution.
The Intergovernmental Panel on Climate Change (IPCC) developed the report, Climate Change 2007', over six years with a panel of 2 500 scientific expert reviewers from 130 countries. Predictions for the future of global warming in the report, intended as a summary for policymakers, are based on 19 computer models. Many scientists and policy makers agree climate change is the biggest problem facing the planet today. A better understanding of global-warming phenomena requires sophisticated models of the Earth System including the atmosphere, ocean, biosphere and cryosphere.
The ability of satellites to deliver global data on the Earth System makes them particularly useful to study climate change and to validate and assess the quality of climate models. In addition, long-term and consistent Earth observation (EO) data sets enable scientists to identify significant trends and patterns in the climate. ESA's Envisat, the world's largest environmental satellite, affords this to scientists by providing continuity of data initiated in the early 1990s with previous ESA satellites ERS-1, ESA's first observation satellite launched in 1991, and ERS-2.
A space-borne instrument known as a radar altimeter offers valuable information on the state of the ocean by providing measurements of the height of the ocean surface. Data acquired by radar altimeters aboard Envisat and ERS show sea levels have been rising by three mm a year since the early 1990s.
Other evidence of global warming can be found in the melting of polar sea-ice and ice caps. Satellites are often the only means of studying the Earth's Polar Regions
Contact: Simonetta Cheli
European Space Agency