It’s interesting how the message is spreading. David and I have been arguing for 2 or 3 years that the feedbacks are the key gaping flaw, the critical point in the skeptic’s case. (And see this post last week.) It’s the amplification in the models with water vapor and clouds which is the point of highest uncertainty (and indeed it’s not just uncertain, the evidence points towards negative feedback. The models are wrong.)
Patrick Moore shared emails with David in February 2012 saying: “Yours is the best straightforward explanation of the skeptic’s rationale that I have seen, and thank-you for that.”
And now we see an interview with Patrick Moore in the Washington Times, sharing the meme:
“What most people don’t realize, partly because the media never explains it, is that there is no dispute over whether CO2 is a greenhouse gas, and all else being equal would result in a warming of the climate. The fundamental dispute is about water in the atmosphere, either in the form of water vapour (a gas) or clouds (water in liquid form). It is generally accepted that a warmer climate will result in more water evaporating from the land and sea and therefore resulting in a higher level of water in the atmosphere, partly because the warmer the air is the more water it can hold. All of the models used by the IPCC assume that this increase in water vapour will result in a positive feedback in the order of 3-4 times the increase in temperature that would be caused by the increase in CO2 alone.
Many scientists do not agree with this, or do not agree that we know enough about the impact of increased water to predict the outcome. Some scientists believe increased water will have a negative feedback instead, due to increased cloud cover. It all depends on how much, and a t what altitudes, latitudes and times of day that water is in the form of a gas (vapour) or a liquid (clouds). So if a certain increase in CO2 would theoretically cause a 1.0C increase in temperature, then if water caused a 3-4 times positive feedback the temperature would actually increase by 3-4C. This is why the warming predicted by the models is so large. Whereas if there was a negative feedback of 0.5 times then the temperature would only rise 0.5C.
The global average temperature has now been flat for the past 15 years, as all the while CO2 emissions have continued to increase. There are only 2 possible explanations for, either there is some equally powerful natural factor that is suppressing the warming that should be caused by CO2, or CO2 is only a minor contributor to warming in the first place.”
Sometimes people ask in comments if we are making any difference and I tell them we are. Silently the message is reaching the layer of intelligent movers and shakers that get things done. Usually it’s invisible, in that the mainstream press doesn’t report the message spreading, though it does report the outcomes — the policy reversals, the skeptical candidates, the falling carbon markets. Because the press didn’t understand the mechanism, the commentators explain it all with other reasons. But ultimately we know that bit by bit, word is getting around that there are serious flaws in the doomsday predictions.
Patrick Moore is one of those people who has earned respect from an influential crowd. The tipping point is just that much closer.