cancel2 2022
Canceled
The RSS monthly satellite global mean surface temperature anomaly data, delayed by the US Government shutdown, are now available. The data show no global warming at all for 16 years 11 months. This dataset could be the first of the five to pass the strict Santer test: no global warming at all for 17 years.
Since no el Niño is now expected until next spring at the earliest, the long run without any global warming at all is likely to continue for another few months.
CO2 concentration, meanwhile, continues its upward trend. And it is this disconnect between rising CO2 concentration and stable near-surface temperatures that makes the present long hiatus in global warming more significant than the previous periods of a decade or more without warming over the 163 years of global mean surface temperatures. In none of the previous periods was CO2 concentration either as high or rising as fast as it is today.
Climate extremists are prone to show the data since 1970 as an “escalator” with a series of “steps” consisting of decade-long pauses, but an overall rising trend:
However, a trend is not a prediction. There is no guarantee that merely because the trend has been upward it will continue upward. The effect of the frequent supra-decadal periods without warming is to constrain the overall warming rate since 1970 to a not particularly thrilling 1.6 Cº/century equivalent. Taking the trend since 1950, a fairer benchmark since the period covers a full warming and cooling cycle of the Pacific Decadal Oscillation, shows warming at a rate equivalent to less than 1.1 Cº/century.
So, can one clearly distinguish an anthropogenic warming signal in these post-1950 data from the data before 1950, when we could have had no measurable influence on the climate?
The answer is No. Professor Richard Lindzen likes to play a game with his audiences. He shows the following slide, and explains that one of the panels represents the global warming over the 52-year period 1895-1946, and the other represents the warming over the 52-year period 1957-2008. He explains that both graphs are to the same scale and invites his audience to guess which is the earlier period and which is the later.
In fact, the later period is on the left. Let us determine the linear warming trends on each of the two periods:
The later period has a very slightly steeper slope than the earlier, but only by the equivalent of a third of a Celsius degree per century. On these figures, it seems difficult to justify the IPCC’s assertion of 95% confidence that most of the warming since 1950 was anthropogenic.
Meanwhile, the discrepancy between IPCC prediction and observed reality in the monthly Global Warming Prediction Index remains glaring. A shame that the IPCC did not deal honestly or clearly with this discrepancy in its latest Summary for Policymakers.
For Santer’s test see: http://wattsupwiththat.com/2011/11/17/ben-santers-17-year-itch/
http://wattsupwiththat.com/2013/10/23/getting-very-close-to-meeting-santers-17-year-warming-test/
Since no el Niño is now expected until next spring at the earliest, the long run without any global warming at all is likely to continue for another few months.
CO2 concentration, meanwhile, continues its upward trend. And it is this disconnect between rising CO2 concentration and stable near-surface temperatures that makes the present long hiatus in global warming more significant than the previous periods of a decade or more without warming over the 163 years of global mean surface temperatures. In none of the previous periods was CO2 concentration either as high or rising as fast as it is today.
Climate extremists are prone to show the data since 1970 as an “escalator” with a series of “steps” consisting of decade-long pauses, but an overall rising trend:
However, a trend is not a prediction. There is no guarantee that merely because the trend has been upward it will continue upward. The effect of the frequent supra-decadal periods without warming is to constrain the overall warming rate since 1970 to a not particularly thrilling 1.6 Cº/century equivalent. Taking the trend since 1950, a fairer benchmark since the period covers a full warming and cooling cycle of the Pacific Decadal Oscillation, shows warming at a rate equivalent to less than 1.1 Cº/century.
So, can one clearly distinguish an anthropogenic warming signal in these post-1950 data from the data before 1950, when we could have had no measurable influence on the climate?
The answer is No. Professor Richard Lindzen likes to play a game with his audiences. He shows the following slide, and explains that one of the panels represents the global warming over the 52-year period 1895-1946, and the other represents the warming over the 52-year period 1957-2008. He explains that both graphs are to the same scale and invites his audience to guess which is the earlier period and which is the later.
In fact, the later period is on the left. Let us determine the linear warming trends on each of the two periods:
The later period has a very slightly steeper slope than the earlier, but only by the equivalent of a third of a Celsius degree per century. On these figures, it seems difficult to justify the IPCC’s assertion of 95% confidence that most of the warming since 1950 was anthropogenic.
Meanwhile, the discrepancy between IPCC prediction and observed reality in the monthly Global Warming Prediction Index remains glaring. A shame that the IPCC did not deal honestly or clearly with this discrepancy in its latest Summary for Policymakers.
For Santer’s test see: http://wattsupwiththat.com/2011/11/17/ben-santers-17-year-itch/
http://wattsupwiththat.com/2013/10/23/getting-very-close-to-meeting-santers-17-year-warming-test/