Agree:
Will Steffen Former executive director of the Australian National University (ANU) Climate Change Institute
Impact of people’s intense activity on Earth far exceeds (170x) that of natural events spread across millenniaDisagree:
Roy Spencer Principal Research Scientist at the University of Alabama in Huntsville
I think it is more likely that the warming is mostly natural. At the very least, we have no way of determining what proportion is natural versus human-caused.
Vladimir Putin The official twitter channel for President of the Russian Federation. Tweets from the Presiden
The warming, it had already started by the 1930s. That's when there were no such anthropological factors, such emissions, and the warming had already started.
Patrick Moore Canadian activist, Greenpeace co-founder
The fact that we had both higher temperatures and an ice age at a time when CO2 emissions were 10 times higher than they are today fundamentally contradicts the certainty that human-caused CO2 emissions are the main cause of global warming
