Climate debate

Sir, It is regrettable that you urge "political support for abatement strategies" before a scientific controversy is settled.¹

Although you are dismissive of those who are critical of the Intergovernmental Panel on Climate Change (IPCC), your leading article nevertheless makes three things quite clear.

1. A crucial chapter of the IPCC's report was altered between the time of its formal acceptance and its printing.

2. Whether in accordance with IPCC rules or not—still a hotly debated matter — “there is some evidence that the revision process did result in a subtle shift ... that ... tended to favor arguments that aligned with the report's broad conclusions". (Critics of the IPCC would have used much sponger words.) The leading article further admits that phrase that might have been (mis)interpreted as undermining these conclusions "disappeared" in the revision process.

3. Unnamed "UPCC officials" now clam Hat the reason for the religious to the chapter was "to ensure that it conformed to a 'policymakers' summary, of the full report...”. Their claim begs the obvious question: should not a summary conform to the underlying scientific report rather than vice versa?

The IPCC summary has many problems of selective presentation of facts,² wit the least of which is that it totally ignores global temperature data gathered by weather satellites, which contradict the results of models used to predict a substantial future warming. It seems to me that IPCC officials, having failed to validate the current climate models, are now desperately grasping at straws to buttress the (rather weak) conclusion that "the balance of evidence suggests a discernible human influence on global climate.. In this crusade to provide a scientific cover for political action at the Global Climate Treaty negotiations in July in Geneva, they (mis)used the work of respected scientists who never made such extravagant claims.^3,4

The scientific response to these recently published papers has not yet appeared. Indeed, some papers quoted in support of the IPCC conclusion had only been submitted for publication and were still in preprint form when the IPCC report was written.

The leading article correctly observance that "the integrity of the reviewing and approval process is … an essential element in assuring the credit of the resulting conclusion". We should not be pushed into adopting hasty policies before journals such as Nature print the scientific responses.

S. Fred Singer
Science & Environmental Policy Project
1600 South Eads Street, Suite #712-S
Arlington, VA 22202-2907
Tel/Fax 703-920-2744

1. Nature 381. 539 (1996).
2: Singer, S. F. Science 271, 581 (1996)
3. Mitchell, J. F. B. et. al. Nature 341, 132-134 (1996).
4. Santer, B. D. et al. Clim. Dyn. 2, 79~S00 (1995).