November 10, 1997
Return to this forum's introduction.
Questions answered in this forum:
Can the science behind global warming predictions be trusted? Can an effective program to reduce greenhouse gas emissions be created? Should there be a tax on gas-guzzling vehicles? Could nuclear power reduce America's greenhouse gas emissions? Can a system of emissions credits reduce America's production of greenhouse gases? Should developing countries be included in a global climate treaty? Viewer comments
October 22, 1997:
A discussion of President Clinton's plan to reduce greenhouse gas emissions.
June 25, 1997:
President Clinton is backing the EPA's push for tougher air quality standards, but critics say they're too costly.
February 18, 1997:
The federal Environmental Protection Agency has proposed new clean air standardsthat have been criticized by some industry, state and local officials.
March 6, 1997:
The fastest rise in temperature for perhaps ten thousand years is having a dramatic effect on the brittle ecosystem of Antarctica.
January 4, 1996
British meteorologists report that the Earth's surface temperature was higher than the average in 1995.
Browse the NewsHour's coverage of science and the environment.
EPA Web site on global warming
Environmental Defense Fund
Ralph Mullinger of Findlay, OH, asks:
Why has the science on this matter been so badly misstated to the media and the public? I've seen a good bit of the U.N.'s Intergovernmental Panel on Climate Change 1995 report on the subject, and it places great emphasis on an awful lot of monumental uncertainties remaining in the science. I'm an economist, and I know that an econometric model extended out 100 years would be good only for entertainment, not actual prediction. Climate modeling is an even newer and more uncertain science, as the IPCC readily admits. Why is anyone trusting it to make public policy, especially as drastic a policy as requiring a 30+ percent cut in our projected fossil fuel use in 2012? Why does anyone think that imposing such an economic disaster upon the U.S. is justified by models of an infant and uncertain science which can be realistically classified only as science fiction?
Dr. Michael Oppenheimer of the Environmental Defense Fund responds:
The case for action is not based only upon the specific predictions of the general circulation models. Rather, it arises from the general characteristics of the problem. As long as greenhouse gas emissions continue near or above current levels, greenhouse gas amounts will continue to build in the atmosphere. This buildup is irreversible on a human timescale because several of the gases have very long lifetimes in the atmosphere. In addition, there is a lag between emissions and manifestation of their main consequences due to the thermal inertia of the oceans.
While the models have large uncertainty at the regional level, they tell us the general character of the global changes expected with fair confidence, since many of the predictions are already manifest. These include a warming of about one degree Fahrenheit over the past century, higher sea level, shrinking glaciers, and more intense precipitation events. In addition, models have "retrocast" past climates with some success. Models are far from perfect, but they do provide a reasonable basis for getting started with emission limitation.
Karen Karrigen of the Global Climate Information Project responds:
First, the reason the science has "been so badly misstated to the media" is the misstaters have a stake in (their) proclamations of disaster gaining currency. Professional and organizational viability are at stake, including funding from membership and government grants and future projects, speaking, writing and possibly teaching engagements. Taxpayers fund global warming research to the tune of $2 billion annually. If we all heard from the grant recipients that global warming was not a threat -- the money would likely dry up and go away.
Second, why has this misstatement perpetuated? Well, what makes a good news story: industrial man faces impending self-created doom, or the earth continues its self regulation of temperatures, etc.? One is "sexy," the other is as exciting as the middle school science lecture all have already heard.
A reply can be summed up with another question: Why was the science so badly misstated and reported when the same merchants were proclaiming the catastrophe of "global cooling" less than 25 years ago?
Also, you are correct, these models are not worth very much, and are continuously being modified (toward "non-catastrophe") as more relevant factors are incorporated; yet they continue to be used to state, for example, the seas are rising, when there is absolutely no basis to claim that climatic models can address sea levels.
Finally, also in response to your closing point, remember that this is another in a series of attempts by parties with the agenda of reducing or eliminating activities of modern man of which they do not approve -- making things, driving things, using and burning things. They tried "the new ice age is coming," and when that fell apart, they're trying this.
Carl Pope of the Sierra Club responds:
The models are not the key issue. The key issue is that the underlying science establishes beyond any doubt that increasing concentrations of greenhouse pollutants will change global weather and climate. The details of that change are indeed impossible to predict. But asking economists what would happen to an economy that stopped investing, and consumed only, for 100 years, would not be an idle exercise even though the econometric models could not measure the exact dimensions of the catastrophe.
We are turning up the heat underneath the teakettle that represents global climate. At some point it will come to a point, and we will be cooked with it. Common sense suggested turning down the heat.
Next: can an effective program to reduce greenhouse gas emissions be created?