The City Square: Global Warming U-Turn

Sunday, February 14, 2010

Global Warming U-Turn

Dr. Phil Jones, a central figure in the UN IPCC global warming cabal and deposed head of the East Anglia Climate Research Unit, has made some startling admissions:

It is interesting that the media, in Europe anyway, now seems free to ask global warmists difficult questions.

The Mail story is based on a BBC interview in which Dr. Jones was asked surprising informed and pointed questions. Although Dr. Jones still maintains that he is "100% confident" in global warming that is caused by man, his admissions are interesting:

A - Do you agree that according to the global temperature record used by the IPCC, the rates of global warming from 1860-1880, 1910-1940 and 1975-1998 were identical?
[discussion of data quality omitted] .... So, in answer to the question, the warming rates for all 4 periods are similar and not statistically significantly different from each other.
Here are the trends and significances for each period:

Period Length Trend
(Degrees C per decade) Significance

1860-1880 21 0.163 Yes

1910-1940 31 0.15 Yes

1975-1998 24 0.166 Yes

1975-2009 35 0.161 Yes

B - Do you agree that from 1995 to the present there has been no statistically-significant global warming
Yes, but only just. ....

Period	Length	Trend (Degrees C per decade)	Significance
1860-1880	21	0.163	Yes
1910-1940	31	0.15	Yes
1975-1998	24	0.166	Yes
1975-2009	35	0.161	Yes

Since the rise in atmospheric CO2 has only been significant for the recent few decades, these earlier warming periods, with warming rates just as high as today, occurred in the absence of man-made greenhouse gases and were thus likely natural. Climate scientists have long known about these earlier warming periods but, since most of the work at Jones' CRU was devoted to proving otherwise, this is a significant admission from him. The interview continues:

G - There is a debate over whether the Medieval Warm Period (MWP) was global or not. If it were to be conclusively shown that it was a global phenomenon, would you accept that this would undermine the premise that mean surface atmospheric temperatures during the latter part of the 20th Century were unprecedented?
There is much debate over whether the Medieval Warm Period was global in extent or not. ....

Wow! After decades of efforts to deny the existence of the MWP, he now allows that there is "much debate."

H - If you agree that there were similar periods of warming since 1850 to the current period, and that the MWP is under debate, what factors convince you that recent warming has been largely man-made?
The fact that we can't explain the warming from the 1950s by solar and volcanic forcing - see again my answer to D.

He admitted (above) that the current heating rate is the same as prior heating rates. So the case for man-made global warming now reduces to "we can't explain the warming" even though it is not much different from prior warmings that were unrelated to greenhouse gases.

N - When scientists say "the debate on climate change is over", what exactly do they mean - and what don't they mean?
It would be supposition on my behalf to know whether all scientists who say the debate is over are saying that for the same reason. I don't believe the vast majority of climate scientists think this. This is not my view. There is still much that needs to be undertaken to reduce uncertainties, not just for the future, but for the instrumental (and especially the palaeoclimatic) past as well.