Dr. Rajendra K. Pachauri, the chairman of the United Nations Intergovernmental Panel on Climate Change (IPCC), compared Bjrn Lomborg, Danish statistician and author of The Skeptical Environmentalist, to Adolf Hitler in an interview with Jyllandsposten, a leading Danish newspaper (Apr. 21).
Dr. Patrick J. Michaels, a climatologist at the
Following on from the comments by MITs Carl Wunsch that the Gulf Stream is safe as long as the wind blows and the Earth turns, several other scientists have used the pages of Science magazine (Apr. 16) to pour scorn on the conceit behind the forthcoming movie, The Day After Tomorrow. The movie is predicated on the idea that unchecked global warming will cause an abrupt climate shift that will cause a new ice age in the
Canadian scientists Andrew Weaver of the
The scientists review of the literature concluded that, It is certainly true that if the AMO [Atlantic Meriodonal Oscillation] were to become inactive, substantial short-term cooling would result in western Europe, especially during the winter. However, it is important to emphasize that not a single coupled model assessed by the 2001 IPCC Working Group I on Climate Change Science (4) predicted a collapse in the AMO during the 21st century. Even in those models where the AMO was found to weaken during the 21st century, there would still be warming over
Pointing out that models that do show AMO collapse are not flux-adjusted like newer models, they conclude, Even the recent observations of freshening in the
In light of the paleoclimate record and our understanding of the contemporary climate system, it is safe to say that global warming will not lead to the onset of a new ice age. These same records suggest that it is highly unlikely that global warming will lead to a widespread collapse of the AMOdespite the appealing possibility raised in two recent studiesalthough it is possible that deep convection in the
In the same issue, pioneering oceanographer Wallace Broecker dismisses the recent report rejected by the Pentagon that is predicated on a similar scenario. He comments in his letter, Exaggerated scenarios serve only to intensify the existing polarization over global warming.
Few issues generate more debate or emotion from activists than global warming. This Earth Day, the National Center for Policy Analysis (NCPA) examines whether fears of human-induced climate change are based on sound science and what impact proposed solutions will have on the climate and the economy.
Come hear leading scientists and policy analysts set the record straight about the reality of climate change.
For more information or to RSVP, please contact Matt Moore or Anna Frederick;
Phone: 202-628-6671; Email: mmoore@ncpa.org Visit us online at www.ncpa.org
Leading Canadian and U.S. climatologists are taking issue with “exaggerated” reports, including one recent study commissioned by the Pentagon, that say global warming could suddenly plunge the world into an ice age.
It is simply not going to happen, say the scientists, who are rejecting the widely disseminated theory that rapidly melting polar ice and glaciers could so upset circulation in the Atlantic Ocean that it will trigger rapid global cooling within a decade.
[…]Columbia University climatologist Wallace Broecker, in a letter in today’s Science, says the report, which has been generating headlines around the world, makes gross exaggerations.
He also believes the science behind the scenario is seriously flawed.
[…]
There has been much alarmist speculation recently that global warming could trigger the collapse of the Gulf Stream. Carl Wunsch, Cecil and Ida Green Professor of Physical Oceanography at MIT, sent a letter to Nature magazine (published in the April 8 issue) stating that such a trigger effect is nearly impossible.
Wunsch wrote that, The Gulf Streams existence is a consequence of the large-scale wind system over the North Atlantic Ocean, and of the nature of fluid motion on a rotating planet. The only way to produce an ocean circulation without a Gulf Stream is either to turn off the wind system, or to stop the Earths rotation, or both. He added, The occurrence of a climate state without the Gulf Stream any time soon within tens of millions of years has a probability of little more than zero.
The British Governments Sustainable Development Commission is worried that the United Kingdom will not be able to meet its Kyoto targets because its economy is behaving in too American a fashion. The Commission, chaired by former Green Party head Jonathan Porritt, frets in a report to Prime Minister Tony Blair released April 14 that, American-style patterns of growth in aviation, road transport and fuel use are wholly unsustainable and will damage the quality of life of present and future generations.
Mr. Porritt remarked that, while economic growth has been faster in the UK than any other European country, this is accompanied by much greater inequality in income, and a long-hours, high-pressure employment culture more characteristic of American society. The report calls on the UK government to use taxation to affect the price of energy and fuel and calls for ministers to adopt more “joined up” thinking over the next five to 10 years. (Daily Telegraph, Apr. 14)
Following the questions raised by Stephen McIntyre and Ross McKitrick over the quality of the data employed by Dr. Michael Mann of the University of Virginia in compiling his now infamous hockey stick graph, Manns interpretations of proxy temperature data are now coming under fire from within the community of paleoclimatologists.
In 2002, Esper et al. published in Science magazine a temperature record for the Northern Hemisphere over the past 1000 years that looked quite unlike the hockey stick. Both the Medieval Climate Optimum and the Little Ice Age were clearly evident. In the March 23 edition of Eos, Esper and other colleagues examine why this should be so. According to the Greening Earth Society, Esper basically eliminates all the possibilities except the technique used to process tree-ring data sets the primary information relied on to construct early portions of the temperature reconstructions.
The problem with tree rings appears to be that their variations reflect more than year-to-year climate differences (temperature and/or precipitation). As the trees age, tree-ring production changes and introduces a spurious trend in the tree-ring series. This aging effect differs among tree species, as well as within species, depending on the trees growing conditions (soil type, elevation, slope aspect, etc.). It becomes difficult to separate trends due to aging from those due to climate.
Although various research groups use different techniques to account for this problem, the absence of ground truth (true temperature) makes it impossible to ascertain whose technique is best. Esper uses a method aimed at retaining long-period (greater than a century or so) variations in the tree-ring records, whereas Mann uses a method that virtually eliminates all long-term variation. Esper concludes, Higher-frequency [decadal] climate variations are generally better understood than lower-frequency variations.
Meanwhile, David S. Chapman, Marshall G. Bartlett, and Robert N. Harris of the University of Utah, published in the April 7 edition of Geophysical Research Letters an examination of how Manns imputation of temperatures from boreholes contradicts their work. Mann argues that borehole records of ground surface temperature (GST) do not accurately reflect surface air temperature (SAT) because of the effects of snowfall. Chapman et al., however, have found that (1) GST tracks SAT extremely well at time scales that are appropriate for climate change considerations. (2) Snow cover can either warm or cool the ground relative to a no snow case and need not lead to any bias. (3) Finally, our observations have not revealed any physical process that would explain the supposed preconditioning of GST by a prior season SAT.
In describing the differences between their work and Manns, Chapman et al. use surprisingly strong language for a scientific paper. They describe three of Manns conclusions as misleading, and his end-point analysis as erroneous and just bad science.
The invaluable www.co2science.org, run by Drs. Sherwood, Craig, and Keith Idso, draws attention this month to two important articles on the reality behind the supposed spread of tropical diseases in a warmer world.
First, Reiter et al. (in Emerging Infectious Diseases 9) examine the response of dengue fever in a significant outbreak in Laredo, Texas and Nuevo Laredo, Mexico in 1999. As co2science.org summarizes, they learned that, “The incidence of recent cases, indicated by immunoglobulin M antibody serosurvey, was higher in Nuevo Laredo [16.0% vs. 1.3%], although the vector, Aedes aegypti, was more abundant in Laredo [91% vs. 37%]. Reiter et al. additionally determined that environmental factors that affect contact with mosquitoes, such as air-conditioning and human behavior, appear to account for this paradox. They found, for example, that the proportion of dengue infections attributable to lack of air-conditioning in Nuevo Laredo [where only 2% of the homes had central air-conditioning compared to 36% of the homes in Laredo] was 55%, which means that 55% of the cases of dengue in Nuevo Laredo would not have occurred if all households there had had air-conditioning.”
Co2science.org summarizes, “Reiter et al. correctly conclude, for example, that if the current warming trend in world climates continues, air-conditioning may become even more prevalent in the United States, in which case, the probability of dengue transmission [there] is likely to decrease [our italics]. And if the economy of Mexico continues to grow (which it will, if its citizens are allowed to freely utilize fossil fuels), the use of air-conditioners will likely gain momentum south of the border, which would lead to even greater decreases in the occurrence of dengue there.
“Clearly, the development of wealth, which currently is dependent on the availability of fossil-fuel-derived energy, will lead to greater decreases in mosquito-borne diseases than any change or stasis of climate ever would.”
The other article, Small et al. (Proceedings of the National Academy of Sciences 100), looks at the impact of climate change on malaria transmission in Africa. According to the Idsos, the researchers “determined that malaria transmission suitability did indeed increase because of climate change in specific locations of limited extent; but in Southern Mozambique, which was the only region for which climatic suitability consistently increased, the cause of the increase was increased precipitation, while areas where the climate became less suitable for malaria transmission had all experienced decreased rainfall. In fact, Small et al. say that climate warming, expressed as a systematic temperature increase over the 85-year period, does not appear to be responsible for an increase in malaria suitability over any [our italics] region in Africa.”
Using the NASA Ecosystem Demography model to trace the evolution of vegetation distribution in the US over the past 300 years, researchers at Princeton University have confirmed that land use changes have significantly affected the US climate.
According to the NASA press release, “The researchers found land cover changes produced a significant cooling effect of more than one degree Fahrenheit in parts of the Great Plains and Midwest as agriculture expanded and replaced grasslands. Farmlands tend to create lower temperatures through increased evaporation. A warming effect was found along the Atlantic coast where croplands replaced forests.
“Compared to forests, croplands are less efficient in transpiration; a daytime process where water evaporates from leaves during photosynthesis and cools the air. A slight warming effect was also observed across the Southwest, where woodlands replaced some deserts.
“The study found land cover changes could impact local precipitation, but not as significantly as they affect temperature. The relatively strong cooling over the central U.S. has probably weakened the temperature difference between land and the Gulf of Mexico, slowing the northern movement of weather systems and resulting in enhanced rainfall across Texas. Consequently, the air masses reaching the Central Lowlands region, including Illinois and Indiana, are drier, causing rainfall reductions.”
Lead researcher N. J. Roy said, “It is important to understand the effects of changing land cover, because it can mitigate or exacerbate greenhouse warming. In the U.S. over the past 100 years, it seems to be offsetting greenhouse warming. The opposite is probably true in most other parts of the world. This finding has also been supported in previous research.”
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