Are Scientists underestimating climate change?



The consensus view of climate scientists, as represented by the 2001 Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report, is that the enhanced greenhouse effect likely will lead to global average surface warming by 2100 of between 1.4° and 5.8°C,and global sea level rise of between 9 and 88 centimeters. This assumes the climate sensitivity is in the range 1.5°–4.5°C for an equilibrium doubling of preindustrial carbon dioxide concentrations, and the Special Report on Emissions Scenarios (SRES) range of emissions scenarios [IPCC, 2000]. However, recent developments suggest that this dated IPCC view might underestimate the upper end of the range of possibilities and shift the probabilities toward an increasing risk of greater warmings and sea level rises by 2100.