Since my comments over at LC quite often tend somehow to get a little mangled by the... er... software, I thought that I would post my—very reasonable—reply here. Especially since it is, perhaps, time that I turned my attention back to the subject.
andrew adams (and others),
The notion that recent changes in climate are caused predominantly by human activity is not some idea which scientists have conjured up in isolation either for political purposes, to try to get funding or just as a convenient way to justify recent warming.
Um. So, how did scientists come up with this explanation?
Let’s ask Phil Jones of the CRU, shall we?Roger Harrabin: If you agree that there were similar periods of warming since 1850 to the current period, and that the MWP is under debate, what factors convince you that recent warming has been largely man-made?
Dr Phil Jones: The fact that we can’t explain the warming from the 1950s by solar and volcanic forcing…
So, since Phil and his friends are unable to account for the warming in terms of volcanos or solar warming, then obviously it must be solely human induced?
What about this mysterious decadal Pacific oscillation that is now, apparently, “masking the warming”? What about cloud formation, or albedo or… or… so many other things, many of which we may not be aware of?
The climate is a pretty Chaotic system and we have, really, very little idea of all of the factors involved. Yes, it may be man-made forcings but, ultimately, it could be something else entirely. Or a mixture of both natural and human, of course.
What does Dr Phil think? [Emphasis mine.]It would be supposition on my behalf to know whether all scientists who say the debate is over are saying that for the same reason. I don’t believe the vast majority of climate scientists think this. This is not my view. There is still much that needs to be undertaken to reduce uncertainties, not just for the future, but for the instrumental (and especially the palaeoclimatic) past as well.
A science that measures temperatures by proxies—especially given the problems with said proxies which have been widely detailed (including the tree ring divergence problem)—and then tries to predict future temperatures is not going to be a black and white issue: quite apart from anything else, the temperature has consistently failed to match the predictions of the climate models.
Now, people will say that this is because the climate is a very complicated system, and the models are still improving—but that is the point about a chaotic system like the climate, isn’t it?
The simple fact is that the evidence (that is, the actual, observed temperatures) has not matched the predictions.
Even if we accept that CRU and IPCC are right, then how should we deal with it? Well, luckily, the IPCC has been kind enough to run some models for us, to help us to decide this—they are known as the SRES models (Special Report on Emissions Scenarios).
There are a number of scenarios there but, for my money, the best outcome is produced by the A1 family.The A1 storyline is a case of rapid and successful economic development, in which regional average income per capita converge—current distinctions between “poor” and “rich” countries eventually dissolve. The primary dynamics are:
- Strong commitment to market-based solutions.
- High savings and commitment to education at the household level.
- High rates of investment and innovation in education, technology, and institutions at the national and international levels.
- International mobility of people, ideas, and technology.
- The transition to economic convergence results from advances in transport and communication technology, shifts in national policies on immigration and education, and international cooperation in the development of national and international institutions that enhance productivity growth and technology diffusion.
This may be the type of scenario best represented in recent literature (e.g., Shinn, 1985; UN, 1990; Schwartz, 1991; Peterson, 1994; Gallopin et al., 1997; Glenn and Gordon, 1997, 1999; Lawrence et al., 1997; Hammond, 1998; Raskin et al., 1998). Such scenarios are dominated by an American or European entrepreneurial, progress-oriented perspective in which technology, especially communication technology, plays a central role.
Now, others—those with ideological problems with markets or economic growth, for instance—may disagree; personally, however, I think that a course of action that eliminates poverty and keeps the planet going seems to me to be a pretty good option to go for.
And note, please, that these scenarios are collated and produced not by a bunch of oil-funded right-wing loons, but by the IPCC—the same organisation whose scientific evidence you accept.
Time to get back on this horse, methinks...