Last week, I pointed out that the climate story of the decade is that the 2000s are on track to be nearly 0.2°C warmer than the 1990s.
The World Meteorological Organization reported today that because humans are altering the climate with greenhouse gas emissions:
The ten warmest years on record have occurred since 1997. Global temperatures for 2000-2008 now stand almost 0.2 °C warmer than the average for the decade 1990-1999.
What of 2008?
The “climate scientists at the Met Office Hadley Centre and the Climatic Research Unit (CRU) at University of East Anglia,” who maintain the global climate record for the WMO, concluded 2008 is “the tenth warmest year on a record that dates back to 1850”:
They say this figure is slightly down on earlier years this century partly because of the La Niña that developed in the Pacific Ocean during 2007.
La Niña events typically coincide with cooler global temperatures, and 2008 is slightly cooler than the norm under current climate conditions. Professor Phil Jones at the CRU said: “The most important component of year-to-year variability in global average temperatures is the phase and amplitude of equatorial sea-surface temperatures in the Pacific that lead to La Niña and El Niño events”.
Dr Peter Stott of the Met Office says our actions are making the difference: “Human influence, particularly emission of greenhouse gases, has greatly increased the chance of having such warm years. Comparing observations with the expected response to man-made and natural drivers of climate change it is shown that global temperature is now over 0.7 °C warmer than if humans were not altering the climate.”
Calculating the changing risk attributable to human influence is part of an ongoing collaboration between the Met Office Hadley Centre and the University of Oxford. Commenting on the dramatically increased odds of such warm years because of human induced climate change, Dr Myles Allen from Oxford University said: “Globally this year would have been considered warm, even as recently as the 1970s or 1980s, but a scorcher for our Victorian ancestors.”
Put another way, 2008 will be almost 0.1°C warmer than the decade of the 1990s as a whole.
Beneath the underlying warming, temperature continues to fluctuate from year to year as a result of natural variations. Stott added: “As a result of climate change, what would once have been an exceptionally unusual year has now become quite normal. Without human influence on climate change we would be more than 50 times less likely of seeing a year as warm as 2008.”
And once again, for all the deniers and delayers touting the coolest year of the decade (if the decade starts in 2001) meme, I stand by my offer to bet $1,000 that the decade from 2010 to 2019 will be warmer than the decade from 2000 to 2009. I’ll even give you 2-to-1 odds or spot you 0.1°C. And I’ll even agree to use the HadCRUT3 global mean surface temperature data set.
Why are there no takers? I get so many of you posting your nonsense on the blog. Are you knowingly blowing smoke, posting irrelevant or erroneous things when you know all along humans are warming the planet?
This post was created for ClimateProgress.org, a project of the Center for American Progress Action Fund.
