Jim Hansen and collaborators recently
posted their analysis of global temperatures in the instrumented period through 2011. Be sure to have a look, especially with their analysis of the factors influencing year-to-year temperature variability, including the apparent recent slowdown in the global warming rate. For those of you preferring the Cliff Notes version, here's the summary.
2011 was only the ninth warmest year in the GISS analysis of global temperature change, yet nine of the ten warmest years in the instrumental record (since 1880) have occurred in the 21st century. The past year has been cooled by a moderately strong La Niña. The 5-year (60-month) running mean global temperature hints at a slowdown in the global warming rate during the past few years. However, the cool La Niña phase of the cyclically variable Southern Oscillation of tropical temperatures has been dominant in the past three years, and the deepest solar minimum in the period of satellite data occurred over the past half dozen years. We conclude that the slowdown of warming is likely to prove illusory, with more rapid warming appearing over the next few years.
That's a scary post to read about during this warm winter we are having.
ReplyDeleteInterestingly, the diminished warming over the last few years is consistent with predictions made by perhaps the first initialized decadal climate prediction efforts, back in 2007 (http://www.sciencemag.org/content/317/5839/796.abstract). Then, the headline-making forecast was for several years of relief from the warming trend (due mostly to La Nina), after which warming was projected to resume. These decadal predictions are now operationalized at the UK Met Office: http://www.metoffice.gov.uk/science/specialist/long-range/global/decadal_fc.html. Decadal prediction is a new science, however, thus the verification efforts are still developing, not to mention the protocols and frameworks for prediction experiments themselves. Nonetheless, the early results are fun to contemplate. Also, acceptance of climate change has been falling in recent years, and one wonders if a return to steady temperature rises would reverse that swing. -Andy W.
ReplyDeleteThanks for the tip on that effort as I was unaware of it. I'll go back and give it a read.
ReplyDeleteNotice how the Daily Mail (UK) decided to depict similar data issued by the Met Office. http://bit.ly/weBRMJ They started their graph in 1997, thus showing temperature nearly flat for the last 15 years.
ReplyDeleteI just noticed that BYU geophysicist Barry Bickmore has a post on this. http://bbickmore.wordpress.com/2012/01/29/the-daily-mail-prints-climate-nonsense/
ReplyDelete