AGW skeptics assert that human greenhouse gases have no effect on global climate.
If it is a faith-based assertion, there is nothing that will change their mind.
If on the other hand, they view it as a factual assertion, then it it is a statement in the scientific arena, and must therefore be capable of being refuted.
They agree that CO2 is a greenhouse gas, that is, that it traps infra red radiation, since this is a physical fact.
They agree that concentrations have risen since the Industrial Revolution, since that is an observed fact.
They accept that global temperatures are rising, since they often say that "climate change is happening, it happens all the time, due to natural variation".
So their case is that although CO2 is a greenhouse gas, and is rising, it makes no contribution to the rise in temperature. Or maybe they mean it makes a negligible contribution.
But the climate models say that it is making a significant contribution.
So they reject the use of climate models out of hand, rather than agreeing that they are, like all machines, a useful but imperfect instrument.
It is impossible accurately to study a complex system as the atmosphere without models.
Therefore there is nothing that will convince them that they are wrong.
Therefore their case is not a scientific case, because science must always be falsifiable.
What this leads to is that just as they accuse us of having an ideological agenda, so also do they have an ideological agenda.
It goes like this:
"I believe in individualism. My prime responsibility is to Me as No 1, also my family if I so choose. I will look after my own interests in my own way, and Government should get out of my face and my backyard. There is no such thing as society. I am not responsible for what happens to others, if bad things happen to them, that is there look out. Sh*t happens.
Individualism demands free market fundamentalism. Individualism means that corporations, which are individual persons in law, must not be subject to any regulation, because the Invisible Hand of the Market will produce the best of all possible worlds.
If global warming were true, it would be necessary for representatives of the people to intervene in the market to make carbon pay for the damage it does.
I reject any intervention in the market.
Therefore I reject the idea man-made global warming.
Nothing will induce me to change my mind on this point, because I am an individualist".
This is not correct.Most "sceptics" do not think that CO2 has no effect.The IPCC documents themselves explain that the effect of CO2 in directly warming the atmosphere is quite small and limited to certain parts of the spectrum, but that a warmer atmosphere can hold more water vapour which has a more potent greenhouse effect so acts as a feedback mechanism.Prof. Lindzen (a climate scientist) and most other "sceptics" accept the first part (its basic science) but dispute that the feedback mechanisms are at all well understood and argue that their are counteracting feedbacks.
ReplyDeleteYou have to go pretty far out to find "sceptics" who say that CO2 is a greenhouse gas but has no effect on global climate.Your post is disingenuous (or you need to be better informed).
JMac
JMac
ReplyDeleteRead again. I said "Or maybe they mean it makes a negligible contribution".
I reject your "disingenuous" claim.
I am sincerely trying to construct the sceptics' case. As you say, there is a range. Maybe my approach is affected by the fact that I am dealing with Daily Mail readers, which is a project that have taken on to find out what the problems are in communicating with non-scientific people.
More importantly, is we both agree that CO2 has a forcing effect, but that you think it is smaller, and the majority think it is larger, then the debate switches to the operational one of what we should do about it.
Do you agree that we should start decarbonising now, or do you think we should wait until all the sceptics are on board with the science?
Yes, in your post you do say “Or maybe they mean it makes a negligible contribution”.
ReplyDeleteBut my point is that the IPCC scientists as well as what I would call mainstream “sceptics” say that CO2 by itself has a small effect on global temperature. But IPCC scientists then claim that the water vapour feedback mechanism enhances the warming to a much higher level. They then write computer programs that attempt to model the various influences on the global climate. The mainstream “sceptical” view (as I understand it- and I may be wrong) is that the models are not adequately representing the various feedbacks (including for example increasing cloud cover) and that the models do not in fact exhibit “skill”. I know that this is a matter of dispute between the scientists and that the majority of scientist do not accept these criticisms and the criticisms come from quite a small minority.
But I would not say that mainstream “sceptics” reject the use of models out of hand, nor would I say that they have the attitude that nothing would convince them that they are wrong. I don’t deny that there are some people with that attitude, but part of the problem I have with your post is the first sentence where “sceptics” are all tarred with the same brush. Even in countering Daily-Mailism do you feel that you are justified in doing that.
JMac
We can agree that the models are not perfect - nothing is perfect - but it is not necessary or wise to insist on perfection in a matter as important as this. The Precautionary Principle kicks in here - we must make the safest choice, and that choice is decarbonisation.
ReplyDeleteSee here:
http://www.blogger.com/post-edit.g?blogID=9192922&postID=4842304093530269701