Dyson disagreed with the scientific consensus that carbon dioxide (CO) is a material driver of planetary temperature increases. He believed that some of the effects of increased CO levels are favourable and not taken into account by climate scientists, such as increased agricultural yield, and further that the positive benefits of CO likely outweigh the negative effects. He was skeptical about the simulation models used to predict climate change, arguing that political efforts to reduce causes of climate change distract from other global problems that should take priority. He also signed the World Climate Declaration entitled "There is No Climate Emergency".