Paris Agreement on Climate Change

Part of the debate – in the House of Commons at 4:06 pm on 7 September 2016.

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Photo of David Davies David Davies Chair, Welsh Affairs Committee, Chair, Welsh Affairs Committee 4:06, 7 September 2016

I do not of course dismiss the possibility that the experts may be right. I have never said they are wrong; I have merely suggested that they ought to be able to answer some fairly basic questions if they expect us as policymakers to go ahead with policies that are going to be profoundly unpopular with the public and which, in many cases, the NGOs that support those policies will not support the consequences of—I will come back to that. The point the hon. Gentleman is making is that if some of this warming is natural, the amount of warming that is not natural is that much greater in terms of the percentage of CO2 that has caused it. [Interruption.] Well, there is another issue that I am tempted to go into, but I have been asked by the Whips to keep it short and I will respect that, and that is whether or not this is a logarithmic increase. In other words—[Interruption.] Yes, I am getting looks from all around. In simple terms, if X amount of CO2 has caused Y amount of warming, would 2X of CO2 cause twice as much warming? People seem to have made the assumption that it would, but of course, in nature things often do not work that way.

Let me return to the Paris agreement. It talks about limiting temperature increases to about 2° of what they were in pre-industrial times. With due respect to the Minister, which pre-industrial times is that? I do not mean to look angry, but which times is he talking about? Presumably 1800 is about the base figure, but pre-industry goes on for about 4 billion years longer than that. We could quite easily go back a few years further and say 2° above temperatures in the medieval warm period, when they were around the same level as they are now. They were around the same temperature as they are now in the Roman optimum, too. I am probably going to mess this point up, but a Greek philosopher—I think he was called Thracius—was writing about date trees in Greece and how they could be made to grow but could not produce fruit, therefore intimating, through that, that temperatures were about the same then as now in Greece because date trees behave in the same way as they did 2,000 years ago. The point I am making is if we took as a pre-industrial basepoint the year 10 AD we could probably carry on merrily putting CO2 into the atmosphere for quite a while yet before we hit 2° degrees above that period.