Hadley Center says we’re warming, not cooling
The deniers/delayer-1000s cite recent U.K. Hadley Center data to promote their “climate is cooling” disinformation. Even Roger Pielke, Jr. is peddling this nonsense with his recent inanely titled post, “Update on Falsification of Climate Predictions.” Falsification? Give me a break!
According to the Hadley Center, the eight warmest years in the global temperature record of 150 are, in order, 1998, 2005, 2003, 2002, 2004, 2006, and 2007. Those are also the eight warmest years in the NASA record in a different order, starting with 2005, then 2007 tied with 1998. Where the heck is the cooling trend? Shame on you, Pielke, for lending your name and website to this delayer-1000 nonsense.
It is only fair to ask what the Hadley Center thinks its data shows (much as we’ve heard NASA explain that its data shows unequivocal warming). Answer: they believe it shows unequivocally that we are in a warming trend, including this decade. They make one of the best analytical points I have seen in the whole discussion of this cooling nonsense:
Another way of looking at the warming trend is that 1999 was a similar year to 2007 as far the cooling effects of La NiÃ±a are concerned. The 1999 global temperature was 0.26 degrees C above the 1961-90 average, whereas 2007 is expected to be 0.41 degrees C above this average, 0.15 degrees C warmer than 1999.
(And this explanation doesn’t even note that total solar irradiance in 1999 was 0.3 W/m2 higher than in 2007, which might actually reduce 2007’s temperature relative to 1999 by some 0.1 degrees C!)
This comes from a terrific page titled “Climate Change Myths” by Prof. John Mitchell, chief scientist at the Met Office. One of the myths he debunks is “Myth 6 — 1998 was the warmest year in the global annual temperature record and this has led some to claim that temperatures have been decreasing ever since.” Here is his reply — it is worth reprinting and reading in its entirety:
1998 saw an exceptional El NiÃ±o event which contributed strongly to that record-breaking year. Research shows that an exceptional El NiÃ±o can warm global temperatures by about 0.2 degrees C in a single year, affecting both the ocean surface and the land air temperatures. It is therefore not surprising that 1998 appears as a warm outlier. Had any recent years experienced such an El NiÃ±o, it is very likely that this record would have been broken. More recently, 2005 was also an unusually warm year, the second highest in the global record, but was not boosted by the El NiÃ±o conditions that augmented the warmth of 1998.
The fact remains that the rise in underlying surface temperature has averaged in excess of 0.15 degrees C per decade since the mid-1970s. A simple mathematical calculation of the temperature change over the latest decade (1998-2007) alone shows a continued warming of 0.1 degrees C per decade. The warming trend can be seen in the graph (right, top) of observed global temperatures. The red bars show the global annual surface temperature, which exhibit year-to-year variability. The blue line clearly shows the upward trend, far greater than the uncertainties which are shown as thin black bars. Recent slight slowing of the warming is due to a shift towards more-frequent La NiÃ±a conditions in the Pacific since 1998. These bring cool water up from the depths of the Pacific Ocean, cooling global temperatures.
Prof. Mitchell then makes the comparison that 2007 was 0.15 degrees C warmer than 1999. Finally, he writes:
The diagram [below] ranks global temperatures for the last 150 years. It can be seen that the 17 warmest years all occur in the last 20 years.
So, yes, the planet is in a major warming trend, the dominant cause of which is human emissions, even recently.
Does anybody doubt that when we get out of the La NiÃ±a and the recent solar irradiance minimum, we will see a string of very hot years? And, indeed, a major article published in Science magazine this summer made this very point, which I blogged on. As I noted, they wrote:
Our system predicts that internal variability will partially offset the anthropogenic global warming signal for the next few years. However, climate will continue to warm, with at least half of the years after 2009 predicted to exceed the warmest year currently on record.
They further predict the year 2014 will “be 0.30 degrees Â± 0.2 degrees C warmer than the observed value for 2004,” which means they predict a 50 percent chance that the warming from 2004 to 2014 will be 3/8 that of the warming of the previous century!
By the way, the Hadley Center also debunks these myths:
- Myth 1: Ice core records show that changes in temperature drive changes in carbon dioxide, and it is not carbon dioxide that is driving the current warming.
- Myth 2: Solar activity is the main driver of climate change.
- Myth 3: There is less warming in the upper atmosphere than at the surface which disproves human-induced warming.
- Myth 4: The intensity of cosmic rays changes climate.
- Myth 5: Climate models are too complex and uncertain to provide useful projections of climate change.
Anyone who still believes these myths — or who wants to see a simple scientific debunking of them — should refer to the Hadley Center website.
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