Climate Change

Climate Sensitivity : Higher Than We Thought

Considering the serious risk that Global Warming poses, I trust that Professor Mark Pagani will forgive my cut and paste from his recent research paper :-

“High Earth-system climate sensitivity determined from Pliocene carbon dioxide concentrations”
Mark Pagani et al. 2009

“Data and modelling for the middle Pliocene (approximately 3 – 3.3 [Million years ago] Myr) indicate that the global mean temperature was 2.4 – 2.9 degrees C warmer than preindustrial conditions, and approximately 4 degrees C warmer during the early Pliocene (approximately 4 – 4.2 Myr). If changes in carbon dioxide and associated feedbacks were the primary agents forcing climate over these timescales, and estimates of global temperatures are correct, then our results imply a very high Earth-system climate sensitivity for the middle (3.3 Myr) to early (4.2 Myr) Pliocene ranging between 7.1 plus or minus 1.0 degrees C and 8.7 plus or minus 1.3 degrees C per CO2 doubling, and 9.6 plus or minus 1.4 degrees C per CO2 doubling, respectively. If only the minimum estimates are considered, Earth-system sensitivity is still substantially higher than the range of probable ‘fast-feedback’ climate sensitivity often discussed, and implies that the impact of global warming acts to promote other feedbacks that substantially magnify warming over longer timescales.”