The globe is warming. Part of the warming is owing to emissions of Carbon dioxide, which absorbs reflected infrared. Part is due to natural causes, such as the bounce back from the last ice age. The proportion of the two causes is not known exactly, but 50/50 might be about it. Reductions in Co2 will help mitigate the warming, but the cuts will need to be drastic: perhaps 50% of current levels and below that may not have any effect (this point has been made, if I recall correctly, by Jim Hansen, the "father of global warming").
I have a few questions still:
1. The Co2 absorption bands: I have read a very interesting article by T.J. Nelson (here) that shows Co2 absorbs reflected infrared in three main bands; that those bands are nearly saturated and that therefore increases in Co2 will not have the same effect on warming that the past increases have. The relationship between Co2 and temperature increase is not exponential, or even arithmetic; it is logarithmic. Doubling the amount of Co2 will not lead to the same increase in temperature as the last doubling of Co2 did.
The analogy made by Nelson that it's like pulling the blinds on a window. The first one darkens the room, the next one makes it darker still the third cuts off all light and thereafter there can be no further darkening. [Ref: 1]
I have raised this question on various Warmist websites, but though my questions or comments on other issues have been answered, this one has not. Hmmm... There's some discussion of it on an ABC.net post (here)*, but the exchange between a Warmist and a Skeptic (aka by the Warmists, a "Denier") is inconclusive, and I would have given the win on points to the skeptic. [Ref: 2].
[Addendum: see below**]
2. Re: Global average temperature: the records of McKitrick. In his refutation of the methodology of McKitrick (2002, in his Taken by Storm), Tim Lambert does not really discuss the what the figures clearly show: that in the Southern hemisphere, at all the stations measured, temperatures between 1979 and 2000 declined over the period. For the globe, the average temperature did not increase or decrease, to any degree of statistical significance. [Ref: 3].
I have done the calculations myself, based on the figures in the spreadsheets linked to by Lambert, and used various trendline analyses to do so (using Excel Functions). And that decline happens whether you use the McKitrik's methodology or Lambert's corrections of McKitrick.
I'm not sure what's going on here.
3. What role for government? Leery as I am of big government and its inefficiencies, I do not think we should be voting for government -- or via governments, the United Nations -- to be given vast swags of money to throw at abatement projects. One I read about recently was CCS -- that is, carbon capture and sequestration -- in the UK. The government is giving 1 billion pounds to a pilot project, but the smart money says it won't amount to anything, and will just go in the pockets of the recipient companies. We'll see.
Much rather set in place some sensible incentives (governments can do that) and let private enterprise get into it. That's what's happening in Germany, with solar photovoltaic. See "Power from on High", in today's New York Times. (PDF if link rots). [Ref 4].
As Thomas Friedman said recently, and I'm paraphrasing here: If we do nothing and the worst happens, then we're in deep doo-doo. If we do something, and nothing happens, then we're still better off with better air quality, new green industries and less reliance on fossil fuels from dangerous states. And if we do it by mainly relying on the private sector, the downside costs will have been minimal. That is, as long as we don't go down the path of allowing governments to take our money and throw it (ie waste it) at the problem.
This last point of Friedman's -- the security argument -- is a very powerful one, in my view, and ought to be more in the thinking of conservatives who so casually deny climate change and the non-fossil-fuel alternatives that would free us from relying on such dodgy states as Saudi Arabia -- promoting, as it does, the nasty Wahabbist doctrine throughout the world, and even in our schools (eg, the UK, here). [Ref 5].
These technologies may have the most effect:
- Photovoltaic solar power.
- Carbon capture and sequestration (or storage).
- Geo-engineering: on which I've written about elsewhere.
* The article on the ABC site, "Climate Change, are you willing to take the risk?", had 800+ comments when I read it, and I waded through most. About half way down is the discussion on absorption bands. There are now 977 comments (24/11).
** Addendum (28 Nov 10): I should have done the simple research before, but here's the counter to the carbon absorption argument. The article is well worth printing out and studying carefully, as are the comments. The authors' summary is:
So, if a skeptical friend hits you with the "saturation argument" against global warming, here’s all you need to say: (a) You’d still get an increase in greenhouse warming even if the atmosphere were saturated, because it’s the absorption in the thin upper atmosphere (which is unsaturated) that counts (b) It’s not even true that the atmosphere is actually saturated with respect to absorption by CO2, (c) Water vapor doesn’t overwhelm the effects of CO2 because there’s little water vapor in the high, cold regions from which infrared escapes, and at the low pressures there water vapor absorption is like a leaky sieve, which would let a lot more radiation through were it not for CO2, and (d) These issues were satisfactorily addressed by physicists 50 years ago, and the necessary physics is included in all climate models. [Ref 6].
 "Cold Facts about Climate warming", T.J. Nelson, Science Notes, 17 March 2003, updated 12 Feb 2010. (pdf).
 "Climate change: are you willing to take the risk?", ABC net. The Drum Unleashed. 2 Nov 2010
 Deltoid: Tim Lambert's much-visited warmist blog, at Scienceblogs.
 "Power from on High": Germany's moves in photovoltaic solar energy, New York Times, 24 November 2010. (pdf).
 "Lessons of Hate at Islamic Schools in Britain", New York Times, 24 November 2010. (pdf).
 "A Saturated Gassy Argument" Spencer Weart in collaboration with Raymond T. Pierrehumbers, Real Climate, 26 June 2007