Burning Issue: Is ‘Fire’ Doom Real? : Television: Environmental disaster miniseries elicits skepticism and admiration from scientists.

Will the world become hellishly hot and parched in the next 25 years as portrayed in the CBS miniseries about global warming, “The Fire Next Time”? Unlikely, a group of scientists and environmentalists said Monday.

Although virtually all of the environmental effects predicted in the first half of the miniseries Sunday evening could occur at some time, “The catastrophic environmental effects portrayed are not scientifically plausible in the near future,” said climatologist Richard Somerville of the Scripps Institution of Oceanography in La Jolla. The series will conclude at 9 tonight on Channels 2 and 8.

Portraying such events in the year 2017 is “quite unrealistic,” said atmospheric scientist Kevin Trenderth of the National Center for Atmospheric Research in Boulder, Colo. “You would have to go to the second half of that century, 40 to 50 years further down the road, before they might be more plausible.”

Furthermore, the creators of the science-fiction epic have compressed into a few weeks a large number of events that are unlikely to happen simultaneously. “In practice, things are more likely to be strung out,” Trenderth said. “You’re not likely to get droughts in the Midwest at the same time hurricanes are flooding the Southeast.”

“The most important thing to understand is that nobody knows exactly what will happen” if extreme global warming does occur, said Chris Flavin, vice president for research of the World Watch Institute. “Anybody that does a scenario is taking a guess.”

But overall, the depiction was “not at all unreasonable,” said climatologist John Firor of the National Center for Atmospheric Research. “I’m sure there will be people saying, ‘There go the environmentalists trying to scare us again.’ But when serious scientists who have spent their whole life’s work (on the greenhouse effect) see something that will give life great difficulty in the future, what do you do about it? Do you tell people and be accused of being a fear monger, or do you keep quiet and not share your results with the people who paid for it?”

Added Firor: “This is a pretty good experiment to see if we can convey complex information to a lot of people.”

Of course, “certain things (in the miniseries) are likelier than others,” said Michael Ghil, director of the Institute of Geophysics and and Planetary Physics at UCLA. Extensive forest fires in California and a significant drought in the Southwest, for example, are environmental effects that could easily happen within the next 25 years, but they are more likely to be associated with a growing population’s increased demand for water than with global warming, he said.

Scientists believe global warming will arise because humans are pouring increasing quantities of carbon dioxide and other so-called greenhouse gases into the atmosphere. These gases allow sunlight to strike the Earth’s surface, but prevent radiation from being reflected back into space, trapping the heat just like the panes of a greenhouse.

The amount of carbon dioxide in the air has increased by 30% since the beginning of the 19th Century, Ghil said, and the average global temperature has increased by about one degree Fahrenheit during the same period.

If the amount of carbon dioxide in the air doubles, as many researchers predict will happen over the next century, the average global temperature could increase another one to four degrees.

But a variety of other factors complicate the prediction process. Water vapor is a very important greenhouse gas because there is so much of it. An increase in global temperatures could increase the amount of water in the air, but that could lead to the formation of more clouds, which reflect sunlight back into space. The huge mass of the world’s oceans might also moderate the effects of increased greenhouse gases.

“It’s really very hard” to predict what will happen, Ghil said.

The miniseries included virtually all of the effects that have been predicted to occur with global warming: the northward migration of insects, tropical diseases and wildlife; drastically reduced yields from current agricultural regions; loss of wetlands that are the breeding sites for much marine life; increased frequency and intensity of hurricanes and monsoons; and increasing international tensions as nations compete for scarce resources.

“The writers have done a good job of going down the list of possible impacts and picking effects to weave in,” Firor said. “They did their homework.”