The scientists and the apocalypse - Climate Change: The Facts - page 171

assessment conducted by another international science body that served as the principal
model for their report.
The International Council of Scientific Unions (ICSU) is constituted of representatives
frommostoftheworld'snationalscienceacademiesandthevariousinternationalscientific
unions. It had long coordinated international geophysical research before establishing a
ScientificCommitteeonProblemsoftheEnvironment(SCOPE)toreporttotheStockholm
conference. Beyond Stockholm, the SCOPE committee continued to commission
environmental assessments, includingoneonthegreenhouseeffect, SCOPE 29 ,completed
in 1985. 4 Not only would this be the forerunner to the IPCC scientific assessment, it was
also the basis for a conference in the Austrian village of Villach that is often hailed as the
birthplace of the climate treaty movement.
Convened in autumn 1985 by the ICSU, along with UNEP and WMO, this conference
generated momentum for urgent global action. The UNEP executive director, Mustafa
Tolba, made a particularly strong case to the 89 invited experts for the commencement of
another treaty process like he was then facilitating to protect the ozone layer. 5 The final
agreed statement concluded that greenhouse warming was 'expected,' that it 'appear[ed]
inevitable,' and that the prospect of catastrophic warming—with the doubling of
greenhouse gas concentrations as early as 2030—required urgent mitigating action. 6 Yet
the SCOPE report itself was of quite a different tenor. Sure, the computer modelling
predicts the usual range of warming for an equivalent doubling of CO 2 (1.5-5.5°C), but
this remains nothing more than theoretical speculation until it is validated empirically. The
section where the progress of this validation is assessed offers the least cause for alarm.
During the 1980s, there was much apprehension in government reviews and elsewhere
aboutclaimsbasedonwhattheVillachstatementcalls'advancedexperimentswithgeneral
circulation models.' But even the modelling advocates recognised that policy commitment
would be unlikely without empirical evidence that, firstly, variations in atmospheric CO 2
concentrations had a significant impact on global climate, and, secondly, that the
contribution of industrial emissions was already having such an impact. The detection of
even the slightest suggestion of an anthropogenic influence might have been sufficient
grounds for policy action but it would surely be the minimum grounds. 7 All the
government-run assessments agreed that the theoretical cause-effect relationship between
emissions and warming had not been established, and this international assessment for
ICSU presented no exception.
The 'Empirical Climate Studies' section of the SCOPE report was compiled at the
Climatic Research Unit, University of Norwich, under Tom Wigley, a leader of 'detection'
research throughout the 1980s. Wigley found not only that the influence of emissions
remained undetected, but also that evidence was insufficient for natural CO 2 variations
causing changes in the past. When, in 1989, Wigley was asked to coordinate the drafting