Site icon Conservation news

Global warming will slow, then accelerate reports ground-breaking model

Global warming will slow, then accelerate reports ground-breaking model

Global warming will slow, then accelerate reports ground-breaking model
mongabay.com
August 9, 2007

Global warming will slow during the next few years but then accelerate with at least half of the years after 2009 warmer than 1998, the warmest year on record, reports a new study that is the first to incorporate information about the actual state of the ocean and the atmosphere, rather than the approximate ones most models use. The research, published by a team of scientists from the Hadley Center in the United Kingdom, appears in the current issue of the journal Science.



“A common criticism of global climate models, particularly for predicting the coming decade, has been that they only include factors, such as solar radiation, atmospheric aerosols and greenhouse gases, which are affected by changes from outside the climate system,” explained a summary from Science. “Likewise, they neglect internal climate variability that arises from natural changes within the system, like El Niño, fluctuations in ocean circulation and anomalies in ocean heat content. These phenomena could lead to short-term changes, especially regionally, that are quite different from the mean warming expected over the next century resulting from human activities.”



Globally averaged annual mean surface temperature anomaly (relative to 1979—2001) forecast by DePreSys starting from June 2005. Image from Smith, et al (2007).

Now scientists led by Doug Smith have developed a modeling system that “predicts both internal variability and externally forced changes” for global climate. Using the model to generate “hindcasts” of previous decades suggest that the model is more accurate than existing models for predicting global surface temperatures.



“Our system predicts that internal variability will partially offset the anthropogenic global warming signal for the next few years,” the authors wrote. “However, climate will continue to warm, with at least half of the years after 2009 predicted to exceed the warmest year currently on record.”



CITATION: Doug M. Smith, Stephen Cusack, Andrew W. Colman, Chris K. Folland, Glen R. Harris, James M. Murphy (2007). Improved Surface Temperature Prediction for the Coming Decade from a Global Climate Model. 10 AUGUST 2007 VOL 317 SCIENCE