“The skeptics contend that forecasts of global warming are flawed and overstated and that the future might even hold no significant warming at all. Some say that if the warming is modest, as they believe likely, it could bring benefits like longer growing seasons in temperate zones, more rain in dry areas and an enrichment of crops and plant life.”

”’The expense [of climate policy] is patently obvious,’ said one of the most outspoken skeptics, Patrick Michaels, a professor of environmental sciences at the University of Virginia and a former president of the American Meteorological Society. ‘If the policy is going to be that expensive, the science should be much less murky than it is now,’ he said.”

James Hansen’s climate alarm back in 1988 attracted mainstream scientific caution and dissent, believe it or not. Full politicization and polarization would come later. So in 1989, there was still sincere interest in the non-alarmist ‘skeptic’ climate scientists in the mainstream Left press, including the New York Times.

Consider this late 1989 piece by New York Times climate science writer William K. Stevens. The front-page article was titled SPLIT FORECAST: DISSENT ON GLOBAL WARMING – A SPECIAL REPORT; Skeptics Are Challenging Dire ‘Greenhouse’ Views.

With this article’s 25th anniversary last week, what is the state of knowledge today in relation to then. And some questions. Might this have been one of Stevens’ best articles, in retrospect? And would the Times today publish a sympathetic update of the non-alarmist case for CO2 enrichment and a fossil-fuel sustainability?

The article follows in its entirety for your then-versus-now evaluation.

As governments try to come to grips with what is widely depicted as a potentially catastrophic warming of the Earth’s surface, dissenting scientists are challenging what they see as unnecessarily gloomy predictions.

The skeptics contend that forecasts of global warming are flawed and overstated and that the future might even hold no significant warming at all. Some say that if the warming is modest, as they believe likely, it could bring benefits like longer growing seasons in temperate zones, more rain in dry areas and an enrichment of crops and plant life.

In any case, they argue, it would be a mistake to take drastic and costly steps to limit emissions of carbon dioxide and other gases that trap the sun’s heat in the earth’s atmosphere until more is known about the problem. These ”greenhouse” gases are building up as a result of human activity, especially the burning of fossil fuels.

Most Have No Firm Position

Exactly how many scientists are involved in serious climatic research is unclear, but experts in the field say it includes fewer than 300 climatologists, meteorologists, geophysicists and people in related fields. Many of them, perhaps the majority, have not taken a firm position in the debate; they say that while the greenhouse theory is valid in general, there are too many uncertainties about its future effects.

Both of the other factions – those who believe global warming to be a clear and definite threat and those who say there is likely to be no significant warming – appear to be in a minority. Authorities on weather and climate can be found in all three groups.

Much of the dissenters’ criticism is aimed at computerized mathematical models of the world’s climate on which forecasts of global warming are largely based. The critics also cite data on past climatic trends, and they say the theory of greenhouse warming has not yet been fully explored.

”It’s not that we have a bad theory,” said Reid A. Bryson of the University of Wisconsin, a leading climate theorist. ”It’s that we have an incomplete theory with a lot of bad science being done.”

Forecast and Its Basis

Most of the dissenters’ assertions are being challenged in turn by scientists who adhere to the better-known view of global warming. This view holds that increasing concentrations of greenhouse gases are likely to cause the average temperature of the air at the Earth’s surface to increase by three to eight degrees Fahrenheit some time in the next century, from the current global average level of 57 degrees. That amount of increase is generally accepted by a number of national and international scientific groups that have sought a consensus on the issue, including various panels of the National Academy of Sciences.

The forecast is based largely on what the forecasters see as the inherent scientific logic of the greenhouse theory and on the computerized simulations of the future atmosphere. The forecasters expect the warming to raise sea levels, through the expansion of warming water and the melting of ice around the world; to change the climate of the globe, and to disrupt weather, human society and balances among plants and animals.

Both the dissenters and those who call for action have been pressing their arguments in Washington as the Bush Administration grapples with pressures to reduce the burning of fossil fuels like coal and oil, which are the main source of human-produced atmospheric carbon dioxide.

Current forecasts of global warming ”are so inaccurate and fraught with uncertainty as to be useless to policy-makers,” Richard S. Lindzen of the Massachusetts of Institute of Technology and Jerome Namias of the Scripps Institution Oceanography in La Jolla, Calif., wrote in a letter to President Bush in late September. The two authorities on meteorology are both members of the National Academy of Sciences.

Their warning was one of several cautionary pleas now coming forth in the aftermath of months of speeches, writings and testimony to Congress by scientists and environmentalists who urge prompt countermeasures. Some important officials in the Administration, including John H. Sununu, the White House chief of staff, have also urged caution until further research is performed.

Arguments and Evidence Computer Models’ Accuracy Debated

Some of the dissenters, including Dr. Lindzen, say the scientific uncertainty could be reduced through a decade or less of intensive research, perhaps in three to five years. They counsel against drastic action to cut fossil-fuel emissions until then.

”The expense is patently obvious,” said one of the most outspoken skeptics, Patrick Michaels, a professor of environmental sciences at the University of Virginia and a former president of the American Meteorological Society. ”If the policy is going to be that expensive, the science should be much less murky than it is now,” he said.

Other scientists have long acknowledged the uncertainties of global warming predictions, but argue that they will not be eliminated in time for effective action to be taken.