It seems to me that there is a deliberate policy by some believers in (C)AGW* to lump all their critics into one box and label them as "Deniers". As I said yesterday,
the apprently deliberate conflation of climate change skepticism with the neo-nazi holocaust denial by environmental activists is insulting to the memory of the six million plus dead, as well as being distinctly innaccurate. Not everyone who has read or commented on these [emails] is a "denialist". In fact I think the majority of informed comment has come from people who are not deniers that the globe has warmed but rather are skeptical about the anthropogenic CO2 global warming hypothesis. Lumping together skeptical engineering and scientific folk with the lunatic fringe is not helpful, neither is pretending that skepticism does not exist in this issue.
I think it is fair to say that most of the leading bloggers beating up about climate change are skeptics: Anthony Watts, Steve McIntyre, "Bishop Hill", The "Devil", Jeff Id and Lucia to list the blogs I read frequently are all loudly saying "show me" not "nah nah nah I can't hear you". I can't speak for them but I too am a skeptic, a "lukewarmer" as it has been described. I think a good deal of this from Roger "the Prat" Pielke Sr and others describes my position admirably:
“In addition to greenhouse gas emissions, other first-order human climate forcings are important to understanding the future behavior of Earth’s climate. These forcings are spatially heterogeneous and include the effect of aerosols on clouds and associated precipitation [e.g., Rosenfeld et al., 2008], the influence of aerosol deposition (e.g., black carbon (soot) [Flanner et al. 2007] and reactive nitrogen [Galloway et al., 2004]), and the role of changes in land use/land cover [e.g., Takata et al., 2009]. Among their effects is their role in altering atmospheric and ocean circulation features away from what they would be in the natural climate system [NRC, 2005]. As with CO2, the lengths of time that they affect the climate are estimated to be on multidecadal time scales and longer.
Therefore, the cost-benefit analyses regarding the mitigation of CO2 and other greenhouse gases need to be considered along with the other human climate forcings in a broader environmental context, as well as with respect to their role in the climate system.”
To put it another way it is blindingly obvious that humans have some effect on the climate because we're turning what would be otherwise forests or steppes into fields, cities and (sometimes) deserts. We are also consuming terawatts of energy which will eventually be radiated as heat and while the energy received from the sun is much greater (174 petawatts according to wikipedia) it is of a similar order of magnitude to the energy generated by the earth's interior. This must have some effect and simple physics, not to mention various well documented Urban Heat Islands, suggests that it will result in the surface warming up slightly on average.
But this is about as far as I'm going. 174 petawatts is roughly 10,000 times more energy than humanity produces so absent some clear proof to the contrary I'm skeptical that humans are causing all or even most of the rise in temperatures over the last 50-100 years. The Pedant General in a guest post at the Devil's Kitchen put it very well and even had some nifty diagrams:
Let's start at the top, and bear with me.
If the climate and recent changes are not unprecedented, then there's nothing to do. Let's go to the pub.
If it is unprecedented, then we need to know why. If we don't know if it is unprecedented or if we don't know why, we need to stop here until we can find out.
If it is unprecedented but it's not us, then we need to question seriously if there is anything that we can do about it and the answer to that is very very likely to be "no".
If it is us, we then to move into economics. Will the damage outweigh the benefit?
And even if the damage does outweigh the benefit, we still need to consider if the cost of stopping the climate change at source is less than the cost of adapting to the problem to minimise the damage.
And even if the mitigation does cost less than adaptation, we need to ask if our only option for mitigation is to subborn all our freedom to a putative benevolent world government.
Only if you can answer "yes" all the way down that chain can you get to Copenhagen.
Really you should read the lot because it puts both HADCRU and the tree-ring hockeysticks into context. But for this post that extract is all we need. The (C)AGW alarmists are all the way down at the bottom right with the Danish prostitutes. The outright deniers are in the pub on the top left. The rest of us are somewhere in the middle getting neither beer not sex. Personally I'm somewhat schizophrenic in that I'm in the "Find out" camp and the "Adapt" camp because I think we really do need to find out whether (C)AGW is correct but I'm fairly sure that no matter what we learn there the best response is going to be adapt to the changes and not try stopping them (although if AGW is proven then the geo-engineering ideas may well be a good "adapt" strategy).
However I suspect if put the global warming case to the majority of folks without chants of "ZOMG we're doomed!" in the background they'd land in the skeptics camp. Especially when they learn just how much lifestyle and income change they will have to embrace to satisfy the green zealots.
Since, thanls to Copenhagen and the various ETS etc. schemes being proposed by world leaders, the required sacrifice is becoming clear it is surely no surprise that more and more people are saying the equivalent of "hang on a second, are you sure? let me see your working" And that is why the CRU leak is so serious for the "alarmists" because it exposes the fact that their working isn't quite as pristine as they want you to think.
This leads me to my "garden wall" metaphor. AGW is presented as being like the wall I've got pictured over on the left. Nice spiffy paintwork, straight lines and so on. When you look at a wall like that you think it's well built, solid and so on. It is, basically, a wall you can rely on (and it has some nice green ivy to make it eco-friendly). Now the various exposures of Steve McIntyre regarding hockeysticks and the GISS temperature series does weaken your belief a little so perhaps its a bit like the wall to the right - still stright and nicely painted but with a whacking great crack in it.
Now you can look at this crack and think that it's a bit worrying. But on the other hand you then look at the rest of the wall and it's like first wall photo (in fact advertent readers will note that there's a bit of overlap and that the two photos are copped parts of the same wall) and decide that one crack is no big deal. Sure the story wall isn't quite as perfect as you'd prefer but it's not a major problem.
Then there's the CRU leak and you discover how your nice solid wall with its straight lines and all has been built. And that's kind of like scraping off the plaster and paintwork and discovering this:
That is to say, a wall with a rather embarrassing dip in the middle that needs some concrete on top and plaster on the side to err "hide the decline".
It may well be that just as this second wall is likely to be just as good as the first one when it comes to stopping curious passers-by peeking, the science behind AGW is going to turn out to be right but messy but to stretch the metaphor slightly, while its OK knowing that a garden wall has been been built a bit sloppily it's not OK to have that same quality as the loadbearing wall of a 4 story building. The problem with (C)AGW is that it's proponents have indeed built a massive great structure of carbon emissions trading, wind power etc. on top of the "human emissions of CO2 are unprecedented" foundation and, thanks to the CRU leak it looks very much as if that foundation is about as sturdy as this second wall.