Despite the findings of climate scientists, the proportions of climate sceptics appear to be increasing in many countries. We model social and political background, value orientations and the influence of CO2 emissions per capita and vulnerability to climate change upon climate scepticism, drawing upon data from the International Social Survey Programme. Substantial differences in the levels of climate scepticism are apparent between nations. Yet cross national data show that climate sceptics are not merely the mirror image of environmentalists. Typical predictors of environmental issue concern, such as education level, postmaterial value orientations and age are poor predictors of climate scepticism. Affiliation with conservative political parties, gender, being unconcerned about ‘the environment’ or having little trust in government are consistent predictors of scepticism. Climate change scepticism is also correlated positively with CO2 emissions and vulnerability to climate change. While high levels of scepticism have been documented among citizens of the United States, scepticism is as high or higher in countries such as Australia, Norway and New Zealand.