SINGAPORE (AFP) - More than 600 business executives and experts began meeting in Singapore on Thursday to discuss how the corporate world can help tackle the threat of climate change.
Garbage in, Garbage out
An Economist's Perspective on Climate Change and the Kyoto Protocol,
by Ross McKitrick. November 2003
http://www.lavoisier.com.au/papers/articles/McKitrick.pdf
The 1992 UN Framework Convention on Climate Change (UNFCCC) defined "climate change" as follows:
- "Climate change" means a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.
( http://unfccc.int/index.html )
The recent Third Assessment Report (TAR) of the Intergovernmental Panel on Climate Change (IPCC) defined it differently ( http://www.ipcc.ch/ ):
- Climate change in IPCC usage refers to any change over time, whether due to natural variability or as a result of human activity.
This is a very important difference: The IPCC is looking for signs of any change, whereas the policy instruments prescribed by the UNFCCC are not triggered unless it is a particular kind of change: that attributable to human activity. When IPCC officials declare that "climate change" is for real, this is about as informative as announcing that the passage of time is for real. Of course the climate changes: if it didn't Winnipeg would still be under a glacier. But the fact that the last ice age ended doesn't imply that the policy mechanisms of the UNFCCC should kick in. That's the problem with the ambiguity over the term "climate change"-and it seems to trip up a lot of people-accepting the reality of "climate change" does not mean accepting the need for policy interventions. And denying that global warming is a problem requiring costly policy measures is not the same as denying "climate change."
| United Kingdom Parliment, Select Committee on Economic Affairs Written Evidence published 21 June 2005 http://www.publications.parliament.uk/pa/ld200506/ldselect/ldeconaf/12/12we16.htm Memorandum by Ross McKitrick, Associate Professor of Economics, University of Guelph INTRODUCTION I am an Associate Professor of Economics at the University of Guelph in Ontario, Canada. I specialize in environmental economics and issues related to climate change. My research is funded by the federally-funded Social Sciences and Humanities Research Council of Canada, through peer-reviewed grant competitions. I am pleased that your Inquiry is taking up issues related to the IPCC process. I have observed this organization very closely over the past few years and I believe a critical outside assessment is overdue. The IPCC exerts tremendous global influence over energy, environment and climate policies, yet is effectively unaccountable. They have not won over any of their prominent critics since the mid-1990s, meanwhile new, credible experts continue to come forward with doubts about the IPCC's credibility. In this submission I would like to explain two concerns I have regarding the IPCC:
1. The lack of connection between the IPCC and the academic economics community One of the striking differences between the Second Assessment Report of 1995 and the Third Assessment Report of 2001 is the loss of participation of mainstream economists in the latter. A comparison of the lists of chapter contributors (especially in Working Group II) between the reports will confirm that the IPCC could no longer claim to have the participation of mainstream professional economists after 1995. In recent years some economists have taken greater notice of the IPCC's work because of the efforts of Ian Castles and David Henderson to focus expert attention on the "Special Report on Emission Scenarios" (SRES). This has led to a growing body of criticism of the IPCC's handling of economic issues. The SRES does not use conventional economic modeling to produce what would normally be called "forecasts" or "projections". They call their outputs "storylines" and "scenarios" and emphasize that they are speculative, yet at the same time they market the results as "predictions". For example, the back cover of the SRES Report states (emphasis added):
The list of contributors to the SRES and to the IPCC (WGII) Report[78] includes a small and non-representative sample of economists, amongst a long list of government bureaucrats and academics from other disciplines. Moreover I know that some of the contributing economists are quite critical of the final Reports. One of them is John Reilly of the Massachusetts Institute of Technology. In an article in Canada's National Post (27 November 2002) he said that the SRES exercise was "in my view, a kind of insult to science" and the method was "lunacy". He said his lab refused a request from the IPCC to let their models be "tweaked" to support the IPCC scenarios. In Canada there is a large community of academic economists, many with an international reputation, working in the fields of natural resource, energy and environmental economics. None of the participants in our annual research study group, numbering close to one hundred members drawn from universities across Canada and the US, is involved with the IPCC or had any hand in the SRES Report. I recently completed a study, [79]coauthored with Mark Strazicich of Appalachian State University, that confirms the SRES emission scenarios are unrealistically high. We used time series econometric methods to analyze data on per capita carbon dioxide emissions for 121 countries around the world. We are able to show that the global per capita CO2 emissions level is a stationary constant (neither drifting nor trending upwards) with a long term mean of 1.14 tonnes per person and a standard deviation of 0.02. The mean has not changed for several decades, and indeed is trending slightly downwards since the early 1980s (see figure below). If emissions average just over 1.1 tonnes per person, and population peaks (as expected) at about nine billion mid-century, we can expect peak emissions of about 10 billion tonnes by 2050. Yet most IPCC scenarios are between 15 and 30 billion tonnes at 2050, a range that sits well above the plausible upper bound.
We calculated the implied global per capita emission levels associated with each of the 40 SRES scenarios over the next 50 years and computed the probability of observing each one. Only seven of the 40 SRES scenarios remain within five standard deviations of the current mean through the year 2050. Many depart more than 10 standard deviations above the observed mean; eight lie more than fifty standard deviations above the observed mean. Most scenarios are so improbable they should never have been published in the first place. The seven scenarios that we found remotely possible imply a range of total global CO2 emissions from 9.1 to 11.2 Gigatonnes as of 2050, with a mean of about 10.1 Gigatonnes as of 2050. Yet, as I mentioned, the bulk of the SRES scenarios imply emissions of 15 Gigatonnes or more as of 2050. I should emphasize that what Mark Strazicich and I did was merely to apply some standard statistical tests for evaluating economic forecasts. It would have been obvious to most economists to do so. In presenting it to our colleagues a typical reaction is surprise that the IPCC didn't check these things themselves. A recently received comment (from one of the few academic economists in North America who has studied the SRES scenarios closely) stated: "the key findings really are important. Essentially, I think they demolish the SRES exercise—something that I think was overdue." The fact that the SRES document was used for the Third Assessment Report without discovering these (and other) problems illustrates my first concern about the lack of serious economics capability in the IPCC milieu. *** |
