Global Warming

Copyright © Nels Tomlinson 2004, 2005, 2006
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This information was on my bookmarks page, but it grew until it seemed to need a place of its own.

The [believe|don't believe|seem neutral] designations indicate whether I think the portion of the site I've linked to [advocates for|advocates against|is neutral on] anthropogenic global warming (AGW). A page which is labeled ``These guys believe.'' will assume that anthropogenic global warming is real, and meaningful, and that that is beyond debate. A page which is labeled ``These guys don't believe.'' will assume that anthropogenic global warming is either false, or debatable. A page which is labeled ``These guys are neutral.'' is not taking an obvious position, or just presenting data. Notice that there is considerable potential for overlap between ``don't believe'' and ``are neutral''. Also notice that a ``don't believe'' site may well accept that the globe is getting warmer: we're talking about whether they believe the ``anthropogenic'' part of anthropogenic global warming.

Do I believe? Well, not quite. Since I live in Juneau, Alaska, I very much hope that global warming is real. It's not all selfishness: there's some reason to believe that a warmer climate would help some of the world's poorest and hungriest people. Unfortunately, I think that global warming, and anthropogenic global warming, may just be too good to be true. Just in case the anthropogenic global warming stuff is true, though, I'm going to burn an extra log tonight.

The sections (now with subsections) are:

You will find some science and facts in the discussions, and some discussion in the science, of course. The Data section should be mostly time series on temperatures, atmospheric gas concentrations, insolation, sunspots, et cetera, that you can run regressions on.

Since `` believe'' sites are dime-a-dozen, I'll only include a few high quality ones. Since ``don't believe'' sites are presenting an unpopular view, I'll include any good ones I find, where ``good'' means reasonable arguments and hard facts. There aren't enough of those in either camp, really.

Science and Facts

The infamous hockey stick graph, and what's wrong with it.

The ``hockey stick'' graph of Mann, et al, seems to be unequivocally debunked (not that that will stop the chicken littles from squawking about it!). That does not mean that there was no global warming in the last century. It does have the potential to radically change the most reasonable interpretation of that warming. In particular, the anthropogenic global warming explanation seems less plausible if the temperature hasn't suddenly shot up with the rising atmospheric CO2 levels.

An article in Science which suggests that the Mann ``hockey stick'' temperature curve is an artifact of the method used to generate it, rather than a feature of the data: Reconstructing Past Climate from Noisy Data. Herr Dr. Storch's thesis seems to be that there is considerably more variability in the historical data than has been recognized, therefore, the currently observed variance is not statistically significant. What does that mean in plain english? The global temperature jumps around enough on its own, just by blind chance, that the changes we're seeing today are probably also happening by blind chance. These guys are neutral. Here's the abstract to his paper:

Empirical reconstructions of the Northern Hemisphere (NH) temperature in the past millennium based on multiproxy records depict small-amplitude variations followed by a clear warming trend in the past two centuries. We use a coupled atmosphere-ocean model simulation of the past 1000 years as a surrogate climate to test the skill of these methods, particularly at multidecadal and centennial time scales. Idealized proxy records are represented by simulated grid-point temperature, degraded with statistical noise. The centennial variability of the NH temperature is underestimated by the regression-based methods applied here, suggesting that past variations may have been at least a factor of 2 larger than indicated by empirical reconstructions.

Corrections to the Mann et al (1998) Proxy Data Base and Northern Hemisphere Average Temperature Series The McIntyre and McKitrick paper (M&M, hereafter). These guys don't believe.

The data set of proxies of past climate used in Mann, Bradley and Hughes (1998, ``MBH98'' hereafter) for the estimation of temperatures from 1400 to 1980 contains collation errors, unjustifiable truncation or extrapolation of source data, obsolete data, geographical location errors, incorrect calculation of principal components and other quality control defects. We detail these errors and defects. We then apply MBH98 methodology to the construction of a Northern Hemisphere average temperature index for the 1400-1980 period, using corrected and updated source data. The major finding is that the values in the early 15th century exceed any values in the 20th century. The particular ``hockey stick'' shape derived in the MBH98 proxy construction — a temperature index that decreases slightly between the early 15th century and early 20th century and then increases dramatically up to 1980 — is primarily an artefact of poor data handling, obsolete data and incorrect calculation of principal components.
The M&M paper itself may be downloaded as a PDF.
Update The article has now been published in the February 2005 issue of Geophysical Research Letters.
Citation: McIntyre, S., and R. McKitrick (2005), Hockey sticks, principal components, and spurious significance, Geophys. Res. Lett., 32, L03710, doi:10.1029/2004GL021750.

A useful popularization of the M&M article.

Other Science and facts

Sunspots are correlated to solar output, and so a reasonable person might think that sunspots have an influence on global temperatures. Look here, at NASA's Solar Physics site, to see some data on sunspots and climate. These guys are neutral. Their time series is below, in the Data section.

Here is a web magazine, CO2 Science, which covers anthropogenic warming, pollution, ozone, and all the trendy stuff. These guys don't believe. Unfortunately, not believing leaves one at a significant disadvantage in the competition for grant money, so they charge a subscription for their magazine. Fortunately, it's only $7.95 a year to read their articles. I recommend it, if you are interested in this issue.

Paleoclimate: from the Global Warming FAQ A history of the Earth's temperature, and of the concentrations of greenhouse gasses, for the last 500,000,000 years. These guys are neutral. Note that their graphs (copied from Wikipedia, they say) show the ``hockey stick'' pattern which McIntyre and McKitrick are debunking, above.

Why Global Warming Would be Good for You What would global warming really do to us? Here is some information. Things will change, but not all change is bad.

Avoiding Global Warming. Ways to avoid global warming, and what they might cost, and whether that cost is worth paying. Some practical suggestions that might be worth doing. These guys are neutral.

Iron versus the Greenhouse. ``With half a shipload of iron, I could give you an ice age.'' A very practical geoengineering solution to the problem of too much CO2 in the atmosphere. You'll find more on it here, and an account of John Martin's work here.

Health and Amenity Effects of Global Warming How much would you pay to live in a warmer climate? These guys are neutral.

A somewhat warmer climate would probably reduce mortality in the United States and provide Americans with valuable benefits. Regressions of death rates in Washington, DC, and in some 89 urban counties scattered across the nation on climate and demographic variables demonstrate that warmer temperatures reduce deaths. The results imply that a 2.5deg. Celsius warming would lower deaths in the United States by about 40,000 per year. Although the data on illness are poor, the numbers indicate that warming might reduce medical costs by about $20 billion annually. Utilizing willingness to pay as a measure of preference, this paper regresses wage rates for a few narrowly defined occupations in metropolitan areas on measures of temperature and size of city and finds that people prefer warm climates. Workers today would be willing to give up between $30 billion and $100 billion annually in wages for a 2.5deg.C increase in temperatures.

Discussion and Metascience

I'm not sure if this is discussion, or metascience, and it's not great poetry. I'm not even sure it belongs here. It does make the point that global warming is mighty handy for people who want an excuse to push others around, and that's a valid point, even if the assumption that anthropogenic global warming is an evil plot is dead wrong. Here it is: Christopher B. Garvey's warm poem. These guys really don't believe.

Warm water Powerful evidence that greenhouse gas emissions are warming the planet also undermines the significance of a discrepancy often cited by global warming sceptics. They give a lot of good links to articles on the controversy on this, and also to introductory articles. In particular, their links on the existence of a concensus are worth following. These guys don't believe.

Dreaming of a rural, low-energy-usage, horse-farming, agrarian paradise? Read this ad from a 1921 issue of Successful Farming magazine. I think this makes the case that pollution isn't evil; it's the unfortunate side effect of the things which let us live longer, healthier, better lives, so that we have leisure to worry about pollution. Click on the picture to see the ad. I've transcribed the text below.

Tractor ad from early 20th Century. Keep The Boy In School

The pressure of urgent spring work is often the cause of keeping the boy out of school for several months. It may seem necessary—but it isn't fair to the boy! You are placing a life handicap in his path if you deprive him of education. In this age, education is becoming more and more essential to success and prestige in all walks of life, including farming.

Should you feel your own education was neglected, through no fault of yours, then you naturally will want your children to enjoy the benefits of a real education—to have some things you may have missed.

With the help of a Case Kerosene Tractor it is possible for one man to do more work, in a given time, than a good man and an industrious boy, together, with horses. By investing in a Case Tractor and illegible illegible Plow and Harrow outfit now, your boy can get his schooling without interruption, and the Spring work will not suffer by his absense.

Keep the boy in school—and let a Case Kerosene Tractor take his place in the field. You'll never regret either investment. They describe themselves with this blurb:

RealClimate is a commentary site on climate science by working climate scientists for the interested public and journalists. We aim to provide a quick response to developing stories and provide the context sometimes missing in mainstream commentary. The discussion here is restricted to scientific topics and will not get involved in any political or economic implications of the science.
Among other things, they have a refutation of McIntyre and McKitrick's work. These guys believe.

Climate Controls ``If we treated global warming as a technical problem instead of a moral outrage, we could cool the world.''
Gregory Benford accepts the idea of anthropogenic global warming, and points out that the real problem is not the heat, but the heat of the discussion. Global warming is part of religious belief for many secular humanists, so rational responses to real problems are ignored or scorned (my summary, not his). Whatever Mr. Benford's beliefs on the subject, I'd classify this paper as These guys are neutral.

Cooler Heads, a group who seem to think that global warming isn't yet proven. This link is to their weekly updates page, so the contents will vary. These guys don't believe.

Global Cooling?

How about global cooling? In 1975, the climatologists thought that the evidence ineluctably pointed to a disasterous global cooling in our future, probably leading to a new ice age. Read what Newsweek had to say about it.

Antarctic animals hit by cooler summers An analysis of 35 years of climate data shows most of Antarctica is cooling down, not warming up, claim US researchers. On the other hand, there is a lot of variation in the climate, as this story of a warm summer shows.

West Antarctic ice sheet is thickening. The ice sheet has been thinning since the last ice age, but is now thicking in some places. The thickening sea ice has caused trouble for the antarctic researchers.

Mass balance of some Norwegian glaciers. Some years it's up, some years it's down.

The Arctic ice pack is thinning. Or, maybe it isn't. See this article in Geophysical Research Letters. Read the conclusion, in particular: he finds considerable variability, but no significant trend, in the polar ice thickness. Similarly, Greenland seems to be cooling, as reported by several researchers in Geophysical Research Letters.

What does ``concensus'' have to do with science?

Is ``scientific concensus'' an oxymoron?

Aliens Cause Global Warming. That's the title, not the theme. The article (by Michael Crichton) talks about the role of consensus in science. You'll also find it here. Based on this speech, at least, this guy doesn't believe.

Speaking of science by concensus, here is some evidence that the ``concensus'' isn't as broad as the proponents of AGW would have us believe. The Leipzig Declaration and the Petition Project have thousands of signatures, by people who don't take AGW as established fact. Notice that the organisers are making an effort to separate the signers who know what they're talking about from those who don't. They make a separate listing of 2,660 physicists, geophysicists, climatologists, meteorologists, oceanographers, and environmental scientists who are especially well qualified to evaluate the effects of carbon dioxide on the Earth's atmosphere and climate, and another separate listing of 5,017 scientists whose fields of specialization in chemistry, biochemistry, biology, and other life sciences make them especially well qualified to evaluate the effects of carbon dioxide upon the Earth's plant and animal life.

Here is a letter to Science by Dr. Benny Pieser. Dr. Peiser analysed about 1,100 abstracts of recent journal articles on ``global climate change'', and found that approximately 1% explicitly endorse the ``concensus view'' (which is that anthropogenic global warming is significant, and real), 29% implicitly accept the ``concensus view'', while the majority do not address it at all. This suggests that ``concensus view'' is an incorrect, misleading term for the view that global warming is real, and caused by human activity. This guy doesn't believe. His letter was written in response to an article by Naomi Oreskes, who does believe. To put Oreskes work in the most favorable light, Peiser's letter raises serious doubts about her interpretation and conclusion. Unfortunately, Science decided not to retract Oreskes article, nor even to run Dr. Peiser's critique of it. Perhaps the editors are mulling a name change to Concensus?


Actual data, time series that you can run regressions on, seem to be hard to find. I don't think that's a healthy sign for the quality of debate. Here's what I've found on the web.

Monthly average sunspot counts from NASA, covering 1749 to the present.

The Mauna Loa CO2 data, atmospheric CO2 concentrations measured in Hawaii from 1958 to present.

Historical CO2 Law Dome Ice Core explanation and data, from the Law Dome in East Antarctica, covering the last 1,000 years.

The Vostok Ice Core Data, an Antarctic ice core which gives a 400,000 year record of atmospheric gas concentrations and reconstructed temperatures (among other things).

The data behind the Mann, et al paper, from the people who discovered the problems with it.

University of Washington site with links to actual time series.

Data for Devils Hole Core DH-11

World glacier inventory, explanation and data. Not a time series, unfortunately. There is a bit more info at the World Glacier Monitoring Service site.

New Global Warming Information

I've started using to keep track of nifty sites I find. My anthropogenic global warming picks are here. Below, you'll find the five most recent sites I've discovered on global warming. This will automatically be updated as I find more sites on this topic, so do check back occasionally.

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