Panel Reaffirms Human Influence On Global Warming

On April 18, the Intergovernmental Pan­el on Climate Change (IPCC) released its latest draft report, which reaffirms and strengthens the major findings of its 1995 assessment of global warming.

The primary conclusion of both as­sessments: The body of evidence sug­gests "there has been a discernible human influence on global climate," primarily because of C02 emissions from burning fossil fuels.

According to the lat­est report, global average surface air temperatures have risen 0.7 to 1.5 °F since 1860 and are likely to rise an additional 1.8 to 9 °F by the end of the 21st century. IPCC is a collaboration of hundreds of scientists sponsored by the United Nations and the World Meteorological Organization.

Also on April 18, the National Oceanic & Atmospheric Adminis­tration (NOAA) reported that lllustration

the average U.S. temperature during the first quarter of the year was 1 °F higher than the previous record set in 1990, breaking all records set during 106 years of instrumental data. "Our cli­mate is warming at a faster rate than ever before recorded," says NOAA Ad­ministrator D. James Baker. "Ignoring climate change and the most recent warming patterns could be costly to the nation. Small increases in global tem­peratures can lead to more extreme weather events, including droughts, floods, and hurricanes."

The rate and duration of the rise in average global temperature during the 20th century appear to have been the largest of any during the past 1,000 years, the IPCC report says.

Better statistical methods for analyz­ing data, better computer models, and a much better synthesis of paleoclimatic data have brought man-made climate change "out of the noise of natural vari­ability," says Kevin E. Trenberth, head of the Climate Analysis Section at the National Center for Atmospheric Re­search in Boulder, Colo., and a lead au­thor of the draft report. A clear anthro­pogenic signal became obvious in about 1980, he says. 'What has happened in

the last decade in particular is outside the realm of what we would have pre­dicted previously," he says.

The IPCC report lists several climate changes that its authors conclude have already taken place. These include an increase in annual precipitation over land in the mid- and high latitudes of the Northern Hemisphere—owing largely to increases in extreme precipitation events—and a decrease in the extent of snow cover in the Northern Hemi­sphere due to early melting. In addition, the thickness of Arctic sea ice in sum­

mer or early autumn has declined 40% over roughly the past three de­cades, while the rate of sea level rise is now faster than at any time during the past 1,000 years.

For the 21st century, the report predicts relatively large increases in the heat index—the temperature the body feels—as temperatures

and humidity continue to rise. On a global basis, aver­age precipitation intensi­ties will strengthen, lead­ing to increased risk of flooding, while drought

will be more likely in midcontinental areas.

by John Heiniy j ^ e largest uncertainty in modeling future climate arises from clouds, the report notes. Major ques­tions remain about whether clouds will dampen or accelerate the temperature rise as they respond to higher levels of C02 in the atmosphere.

This IPCC report is the first of three; the other drafts are expected to be re­leased next month. All will undergo in­dependent scientific and government review and thus are likely to change be­fore being finalized.

Bette Hileman

Republicans Set Their Science Budget House and Senate Republicans, over vo­cal Democratic protests, have complet­ed work on H. Con. Res. 290, which is Congress' answer to the 2001 budget President Bill Clinton unveiled in Feb­ruary. Congress' version is slightly less generous to civilian research and devel­opment programs than Clinton's, which proposed increasing their funding 6% to $43.3 billion.

The resolution allows $42.9 billion, an increase of 5.3% over current fund­

ing, for nondefense R&D in fiscal 2001, according to an analysis of the budget resolution issued by the American Asso­ciation for the Advancement of Sci­ence's R&D Budget & Policy Program. The congressional budget resolution consists of five years' worth of two kinds of spending figures for 20 separate bud­get categories and is a bit hard to inter­pret, so the analysis is helpful.

The increase is attributable, AAAS says, to "a $1.1 billion increase for the National Institutes of Health and suffi­cient funds for a substantial 16.6% in­crease for R&D in the National Science Foundation and an 11.3% increase for nondefense R&D programs in the De­partment of Energy."

Other people, particularly those in Congress' Democratic minority, aren't quite so sanguine about the numbers. Sen. Tom Harkin (D-Iowa), for one, called the budget "woefully inade­quate." During the floor debate on the final report on the resolution, which had been constructed during a conference that Democrats weren't invited to at­tend, Harkin pointed out that the Senate had unanimously voted three years ago to double NIH basic medical research in five years. Although the 2000 budget contained an increase of $2.3 billion that keeps the doubling on track, the current resolution is short by $1.6 billion of the $2.7 billion increase needed in 2001 to meet the doubling target, Harkin said.

According to the executive branch Office of Management & Budget, the resolution means that 20,000 new teach­ers won't be hired to reduce class size; 5,000 communities won't get federal aid targeted for school construction and modernization; and 14,000 fewer re­searchers, educators, and students will receive support from NSF than would have under Clinton's budget plan.

House Budget Committee Chairman John R. Kasich (R-Ohio) sees the bud­get resolution in quite a different light. "As we begin the 21st century," Kasich said in a statement, "this budget heads us in the right direction." He lauds the budget for keeping "Washington's mitts" off Social Security for the second year in a row, for continuing to pay down the federal debt by a trillion dol­lars over five years, and for providing for at least $150 billion in tax cuts over five years.

And Senate Budget Committee Chairman Pete V. Domenici (R-N.M.) pointed out to the critics that, under the resolution, NIH funding is going to get

APRIL 24,2000 C&EN 9