CO2 has an influence but it’s certainly not significant enough for us to worry about. Professor Tim Patterson
There were periods for example in Earth’s history when we had for three times as much CO2. Or periods when we had ten times as much CO2. Professor Nir Shaviv, Institute of Physics, University of Jerusalem
Anyone who goes around and says that carbon dioxide is responsible for most of the warming of the twentieth century hasn’t looked at the basic numbers. Professor Patrick Michaels, Department of Environmental Sciences, University of Virginia
The sun is driving climate change: CO2 is irrelevant. Dr Piers Corbyn
We can’t say that CO2 will drive climate. It certainly never did in the past. Professor Ian Clark, Department of Earth Sciences, University of Ottawa
The pace of global warming is accelerating and the scale of the impact is devastating. The time for action is limited – we are approaching a tipping point beyond which the opportunity to reverse the damage of CO2 emissions will disappear. Eliot Spitzer
We’re running the most dangerous experiment in history right now, which is to see how much carbon dioxide the atmosphere ... can handle before there is an environmental catastrophe. Elon Musk