Fifteen Years With No Global Warming Doesn't Mean There's No Global Warming, Says EPA ChiefOf course, once you actually read the article, you discover the rather important bits that have been left out of the headline.
Fifteen years with no statistically significant increase in global temperatures does not mean that the human race is not causing the climate to change, EPA Administrator Lisa Jackson told CNSNews.com on Tuesday.Note how "Fifteen years with no global warming" becomes "Fifteen years with no statistically significant increase in global temperatures".
This might seem a minor gripe, but it is headlines that get remembered.
the justification for the question is comments made by Phil Jones, referred to later in the article - beyond the point where a lot of readers would have stopped paying attention, I suspect:
In a Feb. 13 interview with the BBC, Prof. Phil Jones, ex-head of the Climatic Research Unit at the University of East Anglia and among the world’s leading experts on global warming, was asked: “Do you agree that from 1995 to the present that there has been no statistically significant global warming?”It's worth noting that Phil Jones, for obvious reasons, is using the HADCRUT data set. Real men GISS.
“Yes,” said Jones, “but only just. I also calculated the trend for the period from 1995-2009. This trend (0.12 per decade) is positive, but not significant at the 95 percent significance level. The positive trend is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods.”
However, even with that in mind, claiming he said there had been no warming trend for 15 years is disingenuous - there was a warming trend, just under the certainty threshold he used, and, over that short a time frame, you probably wouldn't expect to see a significant warming trend.
By concentrating on such a short time frame, the elepant in the room is ignored. There might not have been a 'statistically significant' global temperature increase in the last fifteen years, but that obscures the far more noteworthy fact that these fifteen years have - individually and collectively - been the warmest we have a reliable instrumental record of. 2005 is the warmest year on record, according to the best data (2). 1998 and 2009 are the join second place warmest years.
Of the last fifteen years - 1994-2008 - according to the NOAA rankings, only two (1994 and 1996) are ranked outside the top 15 (coming in at 18th and 20th, respectively). The other thirteen places are crammed with the years between 1995 and 2008. The interlopers, from outside that range, by the way are 1990 and 1991, appearing at 13th and 15th on the list, so that is hardly bucking the trend.
And of course, the best way to look at the data is by viewing the rolling average - Hansen's paper includes the usual 5 year and 11 year rolling averages, which show a very clear, sustained, long term warming trend.
1 - "Fifteen Years With No Global Warming Doesn't Mean There's No Global Warming, Says EPA Chief," by Karen Schuberg. Published by CNSNews.com, 24th of February, 2010. (http://cnsnews.com/news/article/61804)
2 - "If It’s That Warm, How Come It’s So Damned Cold?," by James Hansen, Reto Ruedy, Makiko Sato, and Ken Lo, 2010. (http://www.columbia.edu/~jeh1/mailings/2010/20100115_Temperature2009.pdf)
3 - As per the Wikipedia article, "Temperature record since 1980," viewed on the 26thof February, 2010. (http://en.wikipedia.org/wiki/Temperature_record_since_1880)