Carbon Dioxide

The greenhouse effect will cause major changes in American agriculture during the next 45 years, shifting croplands northward and substantially increasing the demand for irrigation, according to a study being published today in Nature. The study in the prestigious British science journal found that the buildup of carbon dioxide in the atmosphere could be economically beneficial to many American farmers because it increases the yields of crops such as soybeans, wheat and corn. But Cynthia Rosenzweig, one of the paper's 10 authors and an agronomist at Columbia University, said the public should not "wax optimistic" about this study.

Police arrested four boys yesterday in connection with a theft at Audubon High School that netted $4,700 in shop supplies and tools last month. The supplies included 900 cartridges of carbon dioxide used as a propellant. Audubon police said the two 8-year-olds, one 9-year-old and one 10-year-old would be charged with one count each of burglary and theft. Instead of a hearing in juvenile court, the boys will each pay $1,180 in restitution and perform community service, police said.

The U.S. Supreme Court's groundbreaking decision that regulation of so-called greenhouse gases appears to fall under the Clean Air Act is expected to have far-reaching consequences. But for New Jersey and Pennsylvania, experts said yesterday, the biggest impact of Monday's ruling is likely to be what they won't experience - legal challenges to their programs to mandate cleaner-burning cars. Both states have enacted rules based on California legislation that regulates carbon-dioxide emissions from passenger cars and light trucks.

President Bush urged an international conference on global warming yesterday to conduct more study before ordering costly cuts in industrial emissions, but his cautious approach failed to convince many of the delegates. "Environmental policies that ignore the economic factor, the human factor, are destined to fail," he told delegates from 17 nations on the first day of the two-day conference. "All of us must make certain we preserve our environmental well-being and our economic welfare," he said.

Some of America's trendiest upscale cars - including BMWs, Porsches and Cadillacs - are among the worst automotive contributors to the global warming problem, according to a study. Public Citizen, a public-interest group founded by Ralph Nader, said in a study this month that drivers of some high-performance, less fuel-efficient cars might not realize their vehicles were harming the environment. The more gasoline a car uses, the more carbon dioxide it emits. Carbon dioxide is one of the gases that scientists say collect in the upper atmosphere and trap heat on Earth's surface.

In Los Angeles, Mayor Tom Bradley announced a plan last month to plant two million to five million trees by 1994. In Washington, D.C., the American Forestry Association has begun a national "Global ReLeaf" campaign to plant 100 million trees in cities across the nation by 1992. In Harrisburg, Pennsylvania foresters met this week to discuss ways to plant thousands of trees in dozens of communities across the state. Throughout the nation, latter-day Johnny Appleseeds are planting tens of millions of trees as a tangible way of fighting an invisible enemy: the carbon-dioxide buildup that is threatening to heat up the earth's atmosphere.

When scientists talk about the impact of man-made greenhouse gases in the atmosphere, they tend to talk about how hot it will get in the next century. But Jerry Mahlman, one of the country's top climate modelers, told a gathering at the Wistar Institute in Philadelphia last week that to really see the implications of global warming one has to look at the Earth 500 years from now. "The time lags are so long, unless you look far into the future you don't see the full picture," said Mahlman, who heads the National Oceanographic and Atmospheric Administration's Geophysical Fluid Dynamics Lab. So, using powerful computers, Mahlman's lab has peered at what the Earth might be like five centuries from now. And what they see is not a pretty sight.

In the same spirit of human connectedness that marks this holiday season, the year 1988 has produced a new, global metaphor to tie us together: trees. Last summer's boiling temperatures and droughts heightened concern that the feared "greenhouse effect" had indeed set in. Now, a scrappy Los Angeles environmental group, Tree People, backed by the august American Forestry Association, says there is something every one of us can do to counteract global warming: We can plant trees.

There's no time to wait for governmental action to stop global warming, a coalition of environmental and civic groups said yesterday, and it released a list of 101 do-it-yourself steps to curb the "greenhouse" effect. The steps range from switching to energy-saving light bulbs to eating less red meat. "While there's a great deal of talk about legislation and global summits, there has been too little talk of what we can do in our own homes," said Jeremy Rifkin, president of the Greenhouse Crisis Foundation.

Once again, President Bush has taken the short view on energy policy. This week, he reneged on a campaign promise to reduce power plants' carbon-dioxide emissions, which scientists say contribute to global warming. While the fossil-fuel industry is delighted, this turnaround endangers the environment and vexes the international community. It also humiliates Environmental Protection Agency Administrator Christie Whitman, who, with Mr. Bush's blessing, spent the last month trumpeting his support of emissions cuts.