A considerable number of scientists, politicians, and media people vividly draw the specter of global warming and climate change. The mainstream media tells us about a consensus of climatologists that anthropogenic global warming is irrefutable.
A consensus? Since when is science based on consensus? To the extent I know scientific procedures, an idea, supported by some evidence, becomes a hypothesis. When the hypothesis has withstood all attacks, and there is no evidence against this hypothesis, then this hypothesis is promoted to a theory. Even then, the hypothesis or theory can be attacked and refuted at any time. I have never before heard about a hypothesis that has been declared valid by a majority vote.
Fact is, there are many studies that actually contradict or at least fail to validate the anthropogenic global warming hypothesis. Some selected papers are presented here with a brief synopsis and a link to the original document for you to form your own opinion.
NOTE: To access reprints, you will be asked for credentials. Enter "guest" and "allowmein" to enable access.
Chylek P et al, Clim Change 2004; 63: 201-221. Since 1940, the Greenland coastal stations data have undergone predominantly a cooling trend. At the summit of the Greenland ice sheet the summer average temperature has decreased at the rate of 2.2 C per decade since the beginning of the measurements in 1987.
Braithwaite RJ, Progr Phys Geogr 2002; 26: 76-86. There is no sign of any recent global trend towards increased glacier melting, and the data mainly reflect variations within and between regions.
von Storch H et al, Science 2004; 22: 675-682. 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. In other words, natural variation is much higher than expected, and the anthropogenic contribution lower.
Hansen JE, Proc Natl Acad Sci USA 1998; 95: 12753-12758. The summary implication is a paradigm change for long-term climate projections: uncertainties in climate forcings have supplanted global climate sensitivity as the predominant issue.
McIntyre S et al, Gepohys Res Lett 2005; 32: L03710. The "hockey stick" shaped temperature reconstruction of Mann et al. (1998, 1999) has been widely applied. However it has not been previously noted in print that, prior to their principal components (PCs) analysis on tree ring networks, they carried out an unusual data transformation which strongly affects the resulting PCs. Their method, when tested on persistent red noise, nearly always produces a hockey stick shaped first principal component (PC1) and overstates the first eigenvalue...
Douglass H et al, Geophys Res Lett
2004; 31: L13207. (click here for
a full-size scanned reprint, 16 MB download)
This paper presents new evidence that a disparity between models and observations exists. A relative warming of the surface with respect to the troposhphere has been observed, which is contrary to computed climate models. The paper suggests that the disparity may be the result of near-surface processes, particularly on sea surfaces, that climate models do not account for.
Douglass H et al, Geophys Res Lett
2004; 31: L13208. (click here for
a full-size scanned reprint, 6 MB download)
Computer climate models predict greenhouse-based warming with a greater positive trend in higher altitude. Opposed to the models, three independent observed data sets find decreasing trends. The paper finds that computer models, while in mutual agreement, disagree with observed data. The paper furthermore suggests as the most likely explanation that the models fail to fully capture the multidinous climate effects and feedback systems of a possible increase in greenhouse gases.
Roe GH, Baker MB, Science 2007; 318: 629-32: Why is climate sensitivity so unpredictable? Uncertainties in projections of future climate change have not lessened substantially in the past decades (NB - in spite of more and more powerful computers). Climate is a highly nonlinear multiple-feedback system, and "it is evident that ... small uncertainties in feedbacks are highly amplified in the resulting climate sensitivity. We are constrained by the inevitable: the more likely a large warming is for a given forcing (i.e., the greater the positive feedback), the greater the uncertainty will be in the order of magnitude of that warming." In other words, computer models are trying to predict the unpredictable - chaotic, nonlinear feedback systems, computed from present climate with literally millions of iterations - each iteration amplifying errors and uncertainties.
For a more in-depth discussion of the reliability of climate models, please take a look a the following articles:
NOAA hurricane data: Raw data.
Hurricane strikes 1851 - 2004 by decade. No significant increase of the number of
hurricanes can be found. In fact, over the last 2 decades, there is a decrease.
If the above NOAA link has moved, check out the local copy obtained on 09/27/2007.
Kossin JP et al, Gepohys Res Lett 2007; 34: L04815. Corroborating the above: "A globally consistent reanalysis of hurricane viability and trends" - article finds "Using a homogeneous record, we were not able to corroborate the presence of upward trends in hurricane intensity over the past two decades in any basin other than the Atlantic. Since the Atlantic basin accounts for less than 15% of global hurricane activity, this result poses a challenge to hypotheses that directly relate globally increasing tropical SST [sea surface temperature] to increases in long-term mean global hurricane intensity."
Vallina SM et al, Science 2007; 315: 506-508. This article covers the role of dimethylsulfide in cloud formation. DMS is produced in larger amounts at a higher temperature and, through cloud formation, is thought to create a negative feedback on global temperature increases. Therefore, at least, it adds an element of uncertainty to climate models, and the predicted temperature rise may be less severe than anticipated.
Pan Z et al, Geophys Res Lett 2004; 31: L17109. Global warming "less severe" in the Midwest - is what the title says. Data presented in this paper actually shows a cooling trend in a region as large as the US Midwest. See also the article in Science Daily
Brief analysis by the NATIONAL CENTER FOR POLICY ANALYSIS. Geo-historical climate data show that "global warming" is just a blip. This article has moved, click here to read a local copy. The original URL was http://www.ncpa.org/ba/ba345.pdf (accessed in May 2007).
Please don't hesitate to look at the NCPA's Global Warming Primer because it shows data in a similar range as the above citation (e.g., major contributor to greenhouse effect is water vapor, human contribution is 3.4 percent). If you cannot access the Global Warming Primer at the URL above, please download a local copy, accessed 11-30-2007.
Another interesting site for a good overview, altough not a peer-reviewed source, is the Senator Inhofe Press Blog of the US Senate Committee on Environment and Public Works. Most interesting is a compilation found under the link "A Skeptic's Guide to Debunking Global Warming Alarmism". If this page has moved, please click here to obtain a local copy (accessed 12-21-07).
Alternative energy sources: Hoffert ML et al, Science 2002; 298: 981-987. A survey of alternative energy sources. The article states that "Renewable energy is not readily available". But we can be certain that with rising oil prices - and without any government intervention - alternatives will become more attractive as they become economically reasonable. On the other hand, many present government-subsidized activities suffer from unintended consequences. For example, biofuels have been shown to produce more carbon dioxide than expected. In Fargione J et al, Science 2008; 319:1235-7 the researchers found out that the total carbon dioxide freed by burning and decomposition of biomass as a consequence of land clearing in southeast Asia, Brazil, and the USA exceeds the carbon dioxide savings by a factor of between 17 and 420. Searchinger T et al, Science 2008; 319:1238-40 published similar findings - growing crops for bioethanol production nearly doubles greenhouse emissions for 30 years and increases greenhouse gases for 167 years. Irrespective of whether anthropogenic carbon dioxide has an influence on global climate, government-subsidized biofuel production seems to be a waste of taxpayer's money at best and ecologically harmful at worst.
A 2008 publication titled Germany's Solar Cell Promotion - Dark Clouds on the Horizon by M Frondel, N Ritter, CM Schmidt (published as Ruhr Economic Paper vol 40, 2008) shows the risks of government subsidies. While carbon dioxide production is moved in terms of production location, net carbon dioxide production does not change (this is interesting only if the anthropogenic global warming hypothesis should turn out true). More importantly, every job in the solar industry is subsidized by the German taxpayer with Euro 205,000 annually. This is not only dramatically more than the average solar industry empolyee earns, it also shows how expensive solar power and government-subsidized programs in general are.
Solar activity: Friis-Cristensen E and Lassen K. Science 1991; 254: 698-700 Could there be a close link between solar activity and climate change? This article certainly shows a strong correlation. A more recent article by Willson RC. Science 1997; 277: 1963-5 seems to point in the same direction: recent higher solar energy flux has been observed.
And what about the impending next ice age? Check out Crowley TJ, Hyde WT. Transient nature of late pleistocene climate variability. Nature 2008; 456: 226-230.
And don't forget Dr. James Hansen, director of NASA's Goddard Institute for Space Studies in New York, who proposed to sentence global warming critics to jail. What? A scientific hypothesis needs a jail sentence for those who have contradicting evidence? This is really new.