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Bush and Gore on Global Warming: Sizing Up the Candidates
Volume 3, Number 26: 11 October 2000

In the October 2000 issue of Physics Today, there is a Special Report entitled "Presidential Candidates Speak Out on Science Policy," wherein ten questions are posed to Texas Governor George W. Bush and U.S. Vice President Al Gore. The fourth of the questions deals with Global warming; they are asked if they see global warming as a threat, and if they do, what they would do about it if elected President of the United States.

With respect to the first question, Governor Bush states that scientific data show average temperatures have increased slightly over the past century, which is indeed correct. He then says that "both the causes and the impact of this slight warming are uncertain," which is also correct. And he adds that these phenomena "require much more extensive scientific analyses," which is only prudent.

The rest of Governor Bush's comments concern what should be done about the situation. He begins by saying "I oppose the Kyoto Protocol," but the reasons he gives for opposing it have nothing to do with the science of global warming. Nevertheless, he does say "I will work ? to develop the technologies to reduce greenhouse gas emissions."

Vice President Gore begins by stating his belief that "global temperatures are rising and that human activities such as the burning of fossil fuels are at least partly to blame." The way this statement reads suggests that global temperatures are rising now, or at least have done so in the very recent past, which is highly debatable (see our Editorial There Has Been No Global Warming for the Past 70 Years). The Vice President's belief that humanity's burning of fossil fuels is partly to blame for the putative recent warming and the acknowledged longer-term warming is also debatable, having been challenged by the very scientist - NASA's James Hansen - Gore once embraced as a paragon of wisdom on this topic (see our Editorial Global Warming Acknowledgement Appropriate).

Mr. Gore also says "studies have shown that the 20th century has been the warmest century in the past 1000 years, the 1990s have been the warmest decade in the period, and 1998 was the single warmest year on record." In truth, however, only a handful of studies of this subject have made that claim, while many more provide contrary evidence (see the scientific journal articles referenced in our Subject Index under the heading Medieval Warm Period).

In referring to climate model predictions of an eventual greenhouse gas-induced global warming on the order of 2.0 to 6.5F, the Vice President states that likely consequences would be "more extreme weather events, expanded geographic ranges for diseases like malaria and dengue fever, sea level rises, and damage to ecosystems that cannot adapt quickly enough." All of these claims are contradicted by a wealth of real-world observations that have appeared in the scientific literature, many of which are referenced in our Subject Index. For information on extreme weather see Extreme Weather; for materials related to diseases like malaria see Disease; for studies of sea level see Sea Level; and for "damage to ecosystems that cannot adapt quickly enough" see Extinction.

Another claim of Vice President Gore is that the climate change predicted to result from the CO2 emitted by the burning of fossil fuels imperils the reliability of agricultural production. However, experimental evidence that looks at the consequences of simultaneous increases in the air's temperature and CO2 concentration suggests just the opposite, as indicated by the materials discussed in our Editorials Give Peace a Chance by Giving Plants a Chance, In Search of the Second "Green Revolution", and The Fortunate Coupling of Atmospheric CO2 and Temperature Trends. So compelling is the scientific information on this subject, in fact, that Sharon Cowling (1999) of the Institute of Ecology's Climate Impacts Group at Lund University in Sweden writes in Science (285: 1500-1501) that "maybe we should be less concerned about rising CO2 and rising temperatures and more worried about the possibility that future atmospheric CO2 will suddenly stop increasing."

With respect to how he would respond to the "catastrophic changes" he claims will result from the continued burning of large amounts of fossil fuels, Mr. Gore says "I will work with Congress to ensure the earliest possible ratification and most sensible implementation of the [Kyoto] Protocol."

In summary, Governor Bush says little about the science of global warming; but what he says is correct. Vice President Gore, on the other hand, says much; but most of what he says is hotly contested. Besides differing in these respects, each man comes down on opposite sides of the debate to ratify the Kyoto Protocol, candidate Gore saying he is in favor of it, and candidate Bush saying he opposes it. Their reasons for their different stances are also different, Bush citing economic reasons and Gore citing his view of the science.

These are the facts of the matter as we see them. They suggest that Governor Bush, like NASA's James Hansen and colleagues (and many others, including us), is not at all convinced that the historical rise in the air's CO2 content is responsible for whatever warming may have occurred over the past century. Vice President Gore, however, is thus convinced. On the science, therefore, we would give Bush the edge, but not with great enthusiasm; for he still advocates the development of technologies to reduce greenhouse gas emissions. Perhaps this could be forgiven, however, as a prudent insurance policy against the remote possibility that something more akin to Gore's presumed scenario may ultimately be found to be correct; it is also possible that Bush may be thinking of non-CO2 greenhouse gases within this context, which would, of course, significantly re-endear him to us.

Dr. Craig D. Idso
Dr. Keith E. Idso
Vice President

Cowling, S.A. 1999. Plants and temperature - CO2 uncoupling. Science 285: 1500-1501.