Correction Appended

WASHINGTON, July 18— Momentum toward a global warming caused by the greenhouse effect is now so great that there is no way to avoid a significant rise in temperature in the coming century, many scientists around the world now agree.

Even draconian measures to reduce the air pollution that is responsible for the global warming can only buy time to adjust to a warmer world and put a ceiling on the ultimate warming, these scientists say.

It is already time, they warn, to begin planning how to cope with the consequences of the increasing temperature and the associated changes in weather patterns, a rising sea level and other effects.

Yet strong measures to slow emissions from the burning of fossil fuels and reduce the ultimate temperature increase are also crucial, many experts believe. Without preventive action, they say, the pace of change will be so rapid that nature and human society will be seriously disrupted.

''What I fear most is rapid change,'' said Stephen H. Schneider, a climatologist for the National Center for Atmospheric Research in Boulder, Colo. The faster the changes, the more ''surprises and imbalances,'' he said. ''The effects on forests, and of sea level change, will be more damaging.''

''But if the change is slow enough you can study the problems, determine what the regional impacts will be and learn how to adjust,'' Dr. Schneider said. ''For example, you could develop seeds that will be able to take advantage of a longer but drier growing season.''

Some Government officials and scientists are skeptical about the human ability and will to make the kinds of broad adjustments necessary to make a substantial reduction in the pace of global warming. Making the political case for painful countermeasures is hard because scientists still cannot say exactly what and where the disruptions would be.

And some serious conflicts of interest arise. How would curbs in energy use be divided, for example, among rich countries, which now burn the bulk of the world's fuels, and poor countries desperate to develop? Should countries seek to revive faltering nuclear power, which does not produce the carbon dioxide chiefly involved in the greenhouse effect, or should they subsidize conservation and solar energy? Will improvements in energy efficiency meet the need, or must ways of life be altered?

Given the costs of preventive action and the uncertainties about the benefits, some scientists and officials, including members of the Reagan Administration, argue that it makes sense to await more scientific knowledge before implementing expensive measures. There seems to be growing consensus, however, that the dangers of inaction outweigh the risks and costs of acting in face of scientific uncertainty.

One thing, at least, now appears clear to most atmospheric scientists. If the temperature increase is to be held to a minimum, there is no alternative to reducing emissions of carbon dioxide from the combustion of fossil fuels.

Carbon dioxide is chief among the gases emitted by human activity. The gases absorb infrared radiation from the sun that would otherwise be reflected back into the upper atmosphere, thus causing a gradual warming of the lower atmosphere and earth's surface. And among fossil fuels, coal, which is the most plentiful and the cheapest is the worst culprit. Gaining a given amount of heat from coal releases double the carbon dioxide than from natural gas, and a quarter more than from oil.

Other ''greenhouse gases'' include chlorofluorocarbons and halons -widely used industrial chemicals that many nations have agreed to reduce because they also damage the upper atmosphere's ozone layer - as well as methane from agriculture and waste dumps and nitrous oxides from motor vehicles, industry and fertilizers.

Some experts, including Dr. Irving M. Mintzer, a scientist for the World Resources Institute, a Washington research group, believe that the necessary adjustments can be made with relatively little pain if officials move quickly and aggressively.

Dr. Mintzer said the cuts in carbon dioxide emissions could be achieved by measures that would be desirable even without a global warming problem. They include cars that can would get at least 40 miles a gallon as against the United States average of 20 miles a gallon, more efficient light bulbs and electric appliances, urban planning that reduces traffic congestion, better insulated homes, and a halt to the rapid deforestation of the tropics. The clearing of tropical forests contributes to the problem because the giant old trees contain large amounts of carbon that are released when the trees rot or burn.

Other experts, including Lester B. Lave, an economist and environmental expert at Carnegie-Mellon University in Pittsburgh, do not think it will be so easy to slow the global trend.

''If anybody says they have an ice cream syrup recipe for doing it they are pulling our legs,'' he said. 'Less of a Throwaway Society'

Dr. Lave said that with a growing population and expanding economies, the world will need to consume more energy, even if it is used more efficiently. Realistically, he contended, that will require either burning more fossil fuel or a major expansion of nuclear energy.