Climate science: An empirical example of postnormal science

This paper addresses the views regarding the certainty and uncertainty of c limate science knowledge held by contemporary climate scientists. More prec isely, it addresses the extension of this knowledge into the social and pol itical realms as per the definition of postnormal science. The data for the analysis is drawn from a response rate of approximately 40% from a survey questionnaire mailed to 1000 scientists in Germany, the United States, and Canada, and from a series of in-depth interviews with leading scientists in each country. The international nature of the sample allows for cross-cult ural comparisons. With respect to the relative scientific discourse, similar assessments of t he current state of knowledge are held by the respondents of each country. Almost all scientists agreed that the skill of contemporary models is limit ed. Minor differences were notable. Scientists from the United States were less convinced of the skills of the models than their German counterparts a nd, as would be expected under such circumstances, North American scientist s perceived the need for societal and political responses to be less urgent than their German counterparts. The international consensus was, however, apparent regarding the utility of the knowledge to date: climate science ha s provided enough knowledge so that the initiation of abatement measures is warranted. However, consensus also existed regarding the current inability to explicitly specify detrimental effects that might result from climate c hange. This incompatibility between the state of knowledge and the calls fo r action suggests that, to some degree at least, scientific advice is a pro duct of both scientific knowledge and normative judgment, suggesting a soci oscientific construction of the climate change issue.