This blog post follows on from my comments last night under the title Which Climate Change Consensus?, click here. The following information was sent to me by Ian Castles, Visiting Fellow, Asia Pacific School of Economics and Government, The Australian National University.
“One of the most serious problems that has dogged the climate debate at the science-policy interface and confused the public and political discussion of future climate, since greenhouse warming became an issue in the 1980s, has been the issue of terminology. The unfortunate reality is that, whenever scientists, who speak in the language of the IPCC, and policy people, who speak in the language of the FCCC, refer to climate change, they are usually talking about different things. I firmly believe that a great deal of the public and political confusion about climate change in the world today is the direct result of each community having attached its own interpretation and connotations to statements about climate change made by the other.”
… said Dr. John Zillman in a speech titled Our Changing Climate given on World Meteorological Day in 2003. Dr. Zillman headed the Australian Bureau of Meteorology for 25 years, was President of the World Meteorological Organization from 1995 to 2003, and is President of the Australian Academy of the Technological Sciences and Engineering.
In the 2003 speech, Zillman continued,
“In the IPCC community climate change means change on all timescales, irrespective of the cause, and it thus includes both natural variability and any change that may result from human interference with the working of the climate system. Regrettably, in my view, those who negotiated the FCCC chose to define climate change as only that part that is due to human activity.
Thus, when an IPCC scientist says there is unambiguous evidence of climate change, the Convention people (and, of course, the media) hear, and usually promulgate, an unambiguous conclusion that humans have changed the climate.”
In his contribution to a policy paper published by the Academy of the Social Sciences in Australia (ASSA) in February 2005 titled Uncertainty and Climate Change: The Challenge for Policy, Dr. Zillman said that,
“We do not yet understand the natural variability of climate well enough to predict the natural component of change”
and that,
“We do not yet have a sufficient basis for knowing how greenhouse gas emissions will change in the future to enable us to estimate the greenhouse component of the change.”
In February 2004 the leading peer-reviewed journal Ecological Modelling published Climate change: detection and attribution of trends from long-term geologic data (Vol. 171, No. 4: pgs 433-50) by Dr. Craig Loehle of the US National Council for Air and Stream Improvement (NCASI), who has over 100 published papers in applied mathematics and ecology on topics that include statistical models, optimization, simulation, artificial intelligence, fractals, and wavelets.
The abstract of this paper reads as follows:
Two questions about climate change remain open: detection and attribution. Detection of change for a complex phenomenon like climate is far from simple, because of the necessary averaging and correcting of the various data sources. Given that change over some period is detected, how do we attribute that change to natural versus anthropogenic causes? Historical data may provide key insights in these critical areas. If historical climate data exhibit regularities such as cycles, then these cycles may be considered to be the “normal” behavior of the system, in which case deviations from the “normal” pattern would be evidence for anthropogenic effects on climate. This study uses this approach to examine the global warming question. Two 3000-year temperature series with minimal dating error were analyzed. A total of seven time-series models were fit to the two temperature series and to an average of the two series. None of these models used 20th Century data. In all cases, a good to excellent fit was obtained. Of the seven models, six show a warming trend over the 20th Century similar in timing and magnitude to the Northern Hemisphere instrumental series. One of the models passes right through the 20th Century data. These results suggest that 20th Century warming trends are plausibly a continuation of past climate patterns. Results are not precise enough to solve the attribution problem by partitioning warming into natural versus human-induced components. However, anywhere from a major portion to all of the warming of the 20th Century could plausibly result from natural causes according to these results. Six of the models project a cooling trend (in the absence of other forcings) over the next 200 years of 0.2-1.4 degrees C.
With the above information from Ian Castles was a note recommending that Phil Done and others spend less time studying the realclimate website and more time reading some peer-reviewed literature instead.
Ian suggested readers of this blog could start with the John Zillman paper for ASSA, and also the contributions of economist Warwick McKibbin and political scientist Aynsley Kellow which are published in the same Policy Paper. It is available on the ASSA website at http://www.assa.edu.au/publications/op.asp .
Ian suggests we then move on to the paper by Roger Pielke Jr. which can be found at http://sciencepolicy.colorado.edu/admin/publication_files/resource-479-2004.10.pdf .
Jennifer Marohasy BSc PhD has worked in industry and government. She is currently researching a novel technique for long-range weather forecasting funded by the B. Macfie Family Foundation.