The evidence, as judged by the vast majority of scientists working on the issue, is overwhelmingly in agreement that human interference in the climate is occurring. Uncertainty there may be, but it cuts both ways. If there is a small possibility that climate change is anything to worry about, there is similarly a small possibility of a catastrophic 'runaway' greenhouse effect, the consequences of which are likely to be second only to those of global thermonuclear war.
Failing to act on the basis of inevitable scientific uncertainty legitimises continued inefficient use of fuel and resources, and allows government to set a poor regulatory, fiscal and informational framework for promoting good practices.
Head of Science, Greenpeace