The forecasts for sea level rise don’t include 0; the third IPCC report gives an interval of 0.11 to 0.77 m for 1990-2100 rise under the standard emissions projections. I’m not sure why you would assume such an interval should include zero.

Rule number one is evaluating expert forecasts is that the confidence interval is almost always too narrow. If the IPCC provides an interval of 0.1 to 0.7 meters, then a better interval (one which, in expectation, would include the actual answer 95% of the time) would be much wider.

But, again, thanks for the links.

If you want specific, detailed forecasts of future climate change and discussion of the evidence in favor of it, then you should indeed look at the IPCC report. The full report is indeed very long, but there are very helpful summaries of varying length, from a few pages to a few dozen—links are included below. Plus you can skim or just read the sections you care about. If you’re interested in the topic that should not be too much work.

The forecasts for sea level rise don’t include 0; the third IPCC report gives an interval of 0.11 to 0.77 m for 1990-2100 rise under the standard emissions projections. I’m not sure why you would assume such an interval should include zero.
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In general, if one doesn’t know much about a particular scientific field and isn’t willing to put in the time to really learn about it, a good way to proceed is to try and find out what the people who do know what they’re talking about are saying—ie, the relevant scientific community. You can generally figure out which things are reliably known to be true vs. uncertain vs. known to be probably not true by looking at what the relevant community generally agrees is demostrated true/false and what they are still debating.

If you do this with the issue of climate change, you’ll find the position set out in the IPCC reports (and taken by John and the rest of CT) is a pretty good representative of what’s well-known. To see this for yourself, take a look at not just the IPCC report, but the NAS report on climate change, the statement of the Royal Society & various other academies of science (they RS also has many other reports on the topic), the statement of the American Geophysical Union, the statement of the American Meteorological Society, the American Association of the Advancement of Science, etc. There are also numerous news pieces and editorials in the two flagship scientific journals, Science and Nature, which give you a good sense of what scientists are thinking on this issue.

If you’re familiar with the workings of the scientific community, you’ll recognize that vocal agreement of this magnitude is rare and impressive—it’s generally much harder to find out what the community is thinking about a given scientific issue. Because the issue of climate change is so important and so many people make claims (often misinformed, sometimes deliberately dishonest) about the scientific evidence, scientists have made a point of trying to communicate the known facts to the public.

Most honest skeptics, presumably, are just unaware of this evidence. Indeed, if you’ve only heard the case for global warming made by environmentalists and political commentators, then skepticism is definitely in order. Environmental activists in particular routinely make overblown claims and, in my experience, are not infrequently totally wrong.

But the combined certainty of nearly the entire relevant scientific community is very different than the claims of environmentalists. It took a mountain of evidence to obtain—the IPCC’s first assessment back in 1990 found there wasn’t yet enough evidence to conclude that global warming was caused by humans, and even in 1995 the IPCC would only say that “the balance of evidence suggests a discernable human influence” on warming. I can’t see any justification for a skepticism which is aware of the scientific community’s position, yet assumes without evidence that the community is wrong.
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IPCC short summary:
http://www.grida.no/climate/ipcc_tar/wg1/005.htm (notice the small “next page” link)

IPCC longer summary:
http://www.grida.no/climate/ipcc_tar/wg1/010.htm

Reports, statements, etc. by the community:
http://www.royalsociety.org/displaypagedoc.asp?id=6206
http://books.nap.edu/html/climatechange/
http://www.agu.org/sci_soc/policy/positions/climate_change.shtml
http://www.ametsoc.org/POLICY/climatechangeresearch_2003.html
http://www.sciencemag.org/cgi/content/full/306/5702/1686
http://www.sciencemag.org
http://www.nature.com/nature (search for ‘climate change’ or ‘global warming’)

I confess to approaching the global warning crowd as a sceptic. But I like to consider myself an open-minded sceptic, willing to revise his beliefs in the light of the evidence. If smart people like John (and Tim Lambert) think that there is something there, I am ready to listen.

But, to be worth listening to, they need to be specific. They need to provide a summary forecast of what is likely to happen with some sort of confidence intervals. Portraying the choice as one between the “full denialist position” and (what?) being in favor of Kyoto, is not very helpful.

So, it would be useful if, in another post, John specified what the sea level rise will be in, say, 10 or 30 or whatever years (with confidence intervals). My impression now, given what I know about modeling, is that any fair interval would include 0 meaningful change. Yet I am ready to be convinced otherwise.

But all John seems to care about doing is mocking the “denialists.” That’s all fine and fun, but I expect more CT.

Can I explain to you all of the arguments that a climatologist would use to refute oil-industry fueled doubts about global warming? No. But I also can’t answer every argument that creationists advance against evolution. This isn’t because I’m not an intelligent person, but because I’m not a scientist. And on certain matters, I trust the experts – because their expertise has earned them that trust. If mathematicians tell me we have a proof for Fermat’s last theorem, I don’t have to check it myself step by step to have justification for my belief that it is sound. It’s enough that the community of mathematicians has thrown its support behind it. Same with global warming and evolution: the relevant scientific communities see no room for legitimate doubt about the essentials on these subjects, so neither do I.

I’m sure that some of you will object to this mentality of taking what the experts say as fact as elitist or lazy. But people don’t have time to be experts about everything, and we rely on what experts have told us all the time in our daily lives without investigating it ourselves. No one rushes to get back issues of the JAMA when their doctor gives them a prescription so they can make sure that it won’t kill them, and there are legions of other examples I could give to make the same point. So forgive the kind people on this site who are not denialists when it comes to global warming if they don’t want to spend hours producing links and poring over research to satisfy the cranks among you. There’s no reason for them to, and every reason for you to realize that you don’t have the scientific expertise to know what in the hell you are talking about. Epistemology lesson over.

Functional, #53: why am I obliged to give my wholehearted and gullible support to studies

Functional, I understand the near-irresistible temptation to read the words “I disagree,” when they come out of the mouth of someone you perceive to be a leftist, as “I forbid you to say that!” But you really should try to resist it. No one is forcing you to think or say anything you don’t want to, and your use of words like “obliged” and “allowed” just makes you sound exceedingly thin-skinned.

http://www.realclimate.org/index.php/archives/category/climate-science/sun-earth-connections/

(Re #41, #47) Climatologists do not predict the weather. They predict the climate, which is more or less the very-long-term average of the weather. While causality is a problem for any science, in climatology it is partly dealt with by retro-predicting the past climate, using the same models.

Also, if you have a deep skepticism about computer modelling, please stop using your computer!

(Re #51) The possibility of the North Atlantic thermohaline shutdown is not ignored by climatologists. If anything, it illustrates the higher probability of catastrophic change due to accelerated global warming. That global warming might lead some areas to become colder for a while, has been understood for a long time.

It is interesting, to me, how the discourse swaps around, determined by a latent adherence to the same old treadmill of production. So, for instance, when lumbermen were being put out of work because of the spotted owl, supposedly, the anti-enviro people were livid—and now that lumbermen are being put out of work due to the effects of climate change the anti-enviro people switch the topic. The point is to paralyze any change to the system of production that produces such absurd monuments as the retirement package for the outgoing EXXON CEO. But the system is going to change regardless. If the current American economy has been kept afloat by the real estate market, if people’s big investments are in their homes, drastic changes to the environment are going to strike at the heart of their wealth—there is nothing that deteriorates property values more than a big hurricane sweeping away your stuff. Given the increasing population density in areas that are the most vulnerable—the coasts—it is as though Americans are setting themselves up for this disaster.

At some point, all the pseudo-skepticism in the world isn’t going to protect the petro or energy corporations, or the proponents of drift.

Thousands? Really? There are thousands of studies that show that the sun’s cycles have no impact on global warming? Or are you saying that there are thousands of studies that IGNORE the sun’s impact? If the former, I don’t think your statement is accurate. If the latter, then why am I obliged to give my wholehearted and gullible support to studies that ignore a factor that may (in fact) be quite important?

Heh. A hydrogen-producing roof. When can I get one? I bet the local fire dept. will studiously ignore the phone anytime my caller id is displayed.

Which is why simply “using less energy”, not just carbon*, in all facets of life is very important. I (heart) technology as much as anybody, but the consequenses of conservation are safe and obvious, new techy stuff not so much.

*thanks for the tip on the dashes, I almost did it again.

See that is what I am talking about. That snooty assine tone. Who is suppossed to convinced by that and what are they suppossed to be convinced of?

See David Kane’s comment.

If before there was a lot of evidence to support global warming but satellite data cast x amount of doubt on both the models and z amount on the general idea that man made global warming was happening. So I felt the probablity of global warming was y.

After finding out that the satellite data had been revised upwards in 2003 I revised x,y, and z.

(Yea, all in very crude gut way.)

Great the data has been revised again in August 2005. So x, y, and z change again.

But the confidence interval is still very large. There is just so much we clearly don’t know. The examples from above should give people some idea.

http://news.nationalgeographic.com/news/2005/06/0627_050627_oceancurrent.html

http://www.timesonline.co.uk/article/0,,2087-1602579,00.html

We just don’t know how much snow will fall in the Antartic versus how much ice will melt. The ice might melt much fater than anyone has predicted or much slower. We really don’t know. We can look and model and predict but in a very large way we really just don’t know.

And yes you should include the link. I might not have checked. I might have just been offended by the hand waving and just moved on. Fortunately I respect your views enough to have checked.

And if that doesn’t matter why the heck do you post? To here yourself talk?

But, anyway, as I said at first, I’m not an expert, and I don’t know. But given that I don’t know, the proper course, IMHO and at least for me, is skepticism.

Well, as I recall it (with my all too fallible memory) his argument is actually that (most especially with solar) the price performance ratio is improving at such a rate that somewhere around 2030 it will in fact be cheaper than any other method of generation and that that will in itself be the price incentive.

I tend to think he’s actually pessimistic on that point…without getting too technical, I can see advances in labs that make me think that point is going to come earlier. Berkeley (or maybe Lawrence Livermore?) has demo’ed a complex cell (gallium arsenide, gallium nitride and indium I think) with a theoretical efficiency of 60% or so.

There’s other things too: LED light bulbs (an oxymoron but hopefully understandable) use about 10% of the energy of incandescents. Depends on where you look up the figures but lighting is said to be anywhere from 8% to 16% of US electricity usage. They’re really only just becoming commercially available so it will take time, as people replace the housing and office stock, to affect demand: and how much they do depends on how many people are already using flourescents and so on, how much they use the cheaper running costs to have more light instead of cheaper and so on.
But it’s a purely price driven change that I fully expect to see happening over the next few years.

There’s indeed a place in the mix for the subsidy of at least basic research. There’s an Australian team looking at a well known reaction, TiO2, when exposed to both water and sunlight, acts as a catalyst to liberate the hydrogen. According to the (US) DOE this needs to be 10% efficient to be commercially viable. The Oz team are certain that they can get 15% by making roof tiles out of the slag from old titanium smelting operations.

In my professional life I’d be absolutely delighted if there was ever greater subsidy into fuel cells, most especially solid oxide ones. My day job involves the purification and wholesaling of a vital ingredient for a particular type of them and we only need that $10 million grant to build an extraction plant to make that vital ingredient (scandium oxide for anyone interested) as cheap as chips (well, at least relative to its current price).

However, I do feel uncomfortable in calling for public subsidy that will be to my benefit.

But at root my optimism on this particular point is precisely that I’m marginally involved in supplying some of the materials that make such schemes work. And what I see, what researchers and test run type people ask me for, makes me think that those alternative technologies are coming in the next decade or so.

Why, there’s even people sticking scandium atoms inside fullerenes to make a hydrogen fuel tank, which would go a long way to making fuel cells seriously viable for transport applications.

Umm, anyone got $10 million?