The latest issue of the Australian Journal of Agricultural and Resource Economics contains two reviews I wrote on books about global warming/climate change. Both books are highly critical of aspects of what we are told about global warming by the Intergovernmental Panel on Climate Change (the IPCC).

The less controversial one is Climate Change Policy after Kyoto: Blueprint for a Realistic Approach, by Warwick, J. McKibbin and Peter J. Wilcoxen. McKibbin is a highly credentialed Australian economist. In fact he is a member of the board of the Reserve Bank of Australia, so he has some direct influence over the daily lives of all Australians through their decisions about interest rates. McKibbin and Wilcoxen are highly critical of the Kyoto Protocol, arguing that it “is very strict in theory, but completely ineffective in practice”. They believe that the Kyoto Protocol “is economically flawed and politically unrealistic”. Their proposed alternative is a “hybrid” policy, combining features of pollution taxes and tradable pollution permits in a way designed to capture the advantages of each.

McKibbin and Wilcoxen very effectively portray the uncertainties inherent in making projections about global warming and its impacts and they note that there is no reason to believe that the uncertainties will be reduced very much in the near future.

The compounding uncertainties are daunting. There is uncertainty about economic growth and technological change over the coming century. Even if we could predict them, there would still be considerable uncertainty about carbon emissions. Even if we could predict carbon emissions, there would still be uncertainty about average temperatures. Even if we could predict average temperatures, there would still be uncertainty about adverse climate outcomes and their spatial distribution. Even if we could predict climate outcomes, there would still be considerable uncertainty about their economic, social and environmental significance. Overlying all that is uncertainty about the costs and consequences of proposed policy interventions. The authors make it clear that the best available information is actually rather weak.

Christopher Essex and Ross McKitrick, authors of Taken by Storm: The Troubled Science, Policy and Politics of Global Warming, go much further than that. They set out a “Doctrine of Certainty”, consisting of familiar assertions that are to be accepted without question, because, as the Doctrine’s supporters say, “The time for questioning is over.” The Doctrine is:

1. The earth is warming.
2. Warming has already been observed.
3. Humans are causing it.
4. All but a handful of scientists on the fringe believe it.
5. Warming is bad.
6. Action is required immediately.
7. Any action is better than none.
8. [Expressions of] uncertainty [about the science] only cover the ulterior motives of individuals aiming to stop needed action.
9. Those who defend uncertainty are bad people.

In summary, the message of the book is, “The Doctrine is not true. Each assertion is either manifestly false or the claim to know it is false.”

It’s a wonderfully entertaining book, as well as making the reader doubt everything they thought they knew or believed about climate change.

Essex and McKitrick are highly critical of the IPCC, on a range of fronts. For example, they argue that the IPCC’s estimates of adverse impacts from global warming are based on projections and assumptions of the flimsiest basis, and are biased towards the sensational. Even “low end” scenarios used by the IPCC are high compared to historical and current trends (a point also made by Castles and Henderson in a study highlighted in The Economist of 6 November 2003).

The IPCC, they say, has been cavalier and misleading in exploiting adverse events to promote its agenda (e.g. attributing glacier melt in the Himalayas to global warming, and using this to promote CO2 cutbacks, when in fact the trend of air temperatures in the Himalayas has shown no warming).

Most importantly, the IPCC’s own modelling indicates that the Kyoto protocol, even if fully implemented and effectively enforced, would have a miniscule impact. As an investment in our future welfare, it does not nearly stack up. Given the likelihood that scaling up Kyoto would result in increasing marginal costs and decreasing marginal benefits, a larger response would be even less attractive – indeed, disproportionately so.

To me, this seems to be the key point. I am not in a position to judge whether all of the physical science presented by Essex and McKitrick is sound, but arguments about that seem of secondary importance when the IPCC’s own projections, placed into an economic framework, do not support the policy response being advocated.

David Pannell, The University of Western Australia

Further reading

Pannell, D.J. (2004). Review of ‘Climate Change Policy after Kyoto: Blueprint for a Realistic Approach’, by Warwick, J. McKibbin and Peter J. Wilcoxen, Australian Journal of Agricultural and Resource Economics 48(2): 381-384.

Pannell, D.J. (2004). Review of ‘Taken by Storm: The Troubled Science, Policy and Politics of Global Warming’, by Christopher Essex and Ross McKitrick, Australian Journal of Agricultural and Resource Economics 48(2): 377-381.