Meteorological Mayhem!

If you think the weather has gone a bit wacko, you're in good company. Tom Karl, director of the National Oceanic and Atmospheric Administration's climate data center in Asheville, North Carolina and respected keeper of the nation's weather statistics, believes it has, too. Karl and his colleagues have looked at their numbers to see whether this widespread public perception is based in fact. It is subtle work, separating real weather trends from the daily ups and downs of our unsteady atmosphere. But the scientists have found that recent weather has indeed been screwier in several ways---it's been hotter than ever, with bigger, rougher rainstorms, and there has been more hail and snow.

For instance, the ten hottest years in history have occurred since 1980, Karl notes, with 1998 being the hottest of the lot. And more of the rain and snow we get is from larger, wetter storms. North Atlantic storms of the past decade have been far more violent than those of the previous 100 years. In the U.S. Northeast, the frost season now ends N days earlier than it did in midcetury.

"We're seeing increases in extremes of precipitation," Karl says, "including heavy downpours, the kind that lead to flash floods. When we look at the data, especially in the U.S., we see them as a significant change."

It's hard to tie any one event, or even one season's weather---including El Niño effect---to long-term trends. And Karl and other scientists won't do it. But reports from the past two years are intriguing.

The 1996 and 1997 season was a real corker:

In July, record rains flooded Yangtze River farmland.

In November, the largest cyclone in ten years hit India, flattening 10,000 homes and leaving almost 2000 people missing or dead. In Honolulu, almost five times the normal rainfall brought mudslides and floods.

In early January, the worst floods in the region's history hit Oregon and northern California, forcing more than 250,000 people from their homes. Early, heavy snow was largely responsible for killing half of Yellowstone's buffalo herd.

The heaviest flooding and rain in 30 years hit Brazil and Bolivia in February, and a single mudslide killed 300 in Peru.

In March, floods inundated parts of the U.S. Midwest. Ninety percent of Grand Forks, North Dakota was submerged in freezing water from the Red River, which had swollen to twice normal flood height.

In April, the third-largest recorded snowstorm hit Boston.

The 1997 and 1998 season has been even more traumatic. Each month this year has seen a record for global temperatures---the highest in at least the past 600 years, according to one study. Glaciers around the world are melting, and rainfall worldwide has increased two percent since 1900, according to NASA's Goddard. Institute for Space Studies. The jet stream, that high river of wind that affects weather closer to the ground, has been rushing overhead at up to twice its normal speed. And in the past decade, more of the U.S. has experienced either extreme drought or extreme moisture than at any other period in the past 100 years. All this activity has been intensified by this year's strong El Niño effect, that warming of the eastern tropical Pacific Ocean that skews normal weather patterns. In 1998, suspicious incidents have included:

Rainfall in the Ohio Valley, New England, the upper Mississippi Valley and Los Angeles was more than 200 percent above normal. Rivers in 17 states were near or above flood stage by July.

While the most violent, F5 tornadoes are rare in any year, three touched down in the U.S. in the first half of 1998. The U.S. tornado death count was the highest in 24 years.

Snow fell in Guadalajara, Mexico for the first time since 1881.

Texas, Florida, Louisiana and parts of Georgia got only 25 percent of normal rainfall amid a tremendous heat wave---north Texas had a full month of temperatures over 100 degrees.

Every county in Florida was hit by wildfires in June and July, driving more than 120,000 people from their homes.

Elsewhere in the world, the worst cyclone in 25 years hit India, killing more than 400 people. Flooding of the Yangtze River killed 3000 and dislocated millions. Monsoons in Bangladesh marooned more than 8 million. Unusually strong rains in Africa killed 2000 and forced 250 million from their homes. Peru gained a new 2300-square-mile lake from its share of the deluge. A tsunami in Papua New Guinea killed thousands.

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Such bedlam is expensive. Damage from the Florida fires was well over $250 million. Hurricane Andrew, which flattened a good deal of south Florida in 1992, wreaked $30 billion in damages, making it the nation's priciest natural disaster. In the years since, Florida homeowners have seen their insurance rates jump an average of 72 percent. The blizzard of 1996 cost $3 billion in the Northeast. And the year before, drought in the U.S. Midwest helped jack up grain prices to a two-decade high---ultimately adding $200 to an average family's annual supermarket bill.

No wonder we wake up to the Weather Channel and trot to Wal-Mart to buy weather porn videos. Still, we don't know much about how weather works. Hundreds of years after Ben, Franklin and son survived Ben's harebrained feat of flying a kite into lightning, we don't really understand how thunderstorms make electricity. Meanwhile, people continue to be struck by lightning on golf courses, zapped through the phone while talking during a storm and fried in their bathtubs by a bolt through the plumbing.

Most climate scientists worldwide now agree that the planet is warming and that humans have had a hand in it. Karl and many others think cloudbursts and scorching summers are the first warped greenhouse chickens come home to roost. Some man-made air pollutants---mainly carbon dioxide and methane---let sunlight into the atmosphere but trap heat on its way out. The process works a lot like an ordinary nursery greenhouse. The sun's rays enter through the glass and warm the inside. Part of this warmth returns to the atmosphere as heat---infrared---radiation but is stopped by greenhouse gases. Gradually the earth's surface warms.

Most other environmental problems we've apparently caused in the upper air have been brought on by burning fossil fuels---coal, oil and natural gas. We've apparently caused in the upper air have been brought on by burning fossil fuels---coal, oil and natural gas. We've made real (largely unnoticed) progress on a couple of high-altitude fronts. Two of the big three upper-atmosphere pollution problems are well on their way to correction. (A fourth, the oxidizing capacity of the planet, is so little understood that we don't yet know if it's a major threat.)

The once-ominous ozone hole, for instance, is caused mostly by chlorofluorocarbons. A study in 1974 showed how highaltitude ozone, which screens out some ultraviolet radiation, could be destroyed by the chlorine released from CFCs. Some forms of ultraviolet radiation have been reported to cause skin cancer and cataracts. In 1985, the ozone over Antarctica had not only thinned (as it had every winter), it had disappeared altogether. Two years later, British Prime Minister Margaret Thatcher and President Ronald Reagan endorsed an international agreement in Montreal to phase out the manufacture of CFCs. George Bush, with the cooperation of DuPont, the predominant domestic maker, accelerated the phaseout and other countries followed suit. You haven't been able to buy a CFC-aerosol can in the U.S. for more than a decade. By 2040, the ozone shield should be back to normal. As veteran environmental journalist Gregg Easterbrook observed in A Moment on the Earth, "If most of the world's important issues could be resolved as quickly as ozone depletion can, earth would be a paradise."

Controlling acid rain has been tougher. In the Northeast it is largely caused by coal burned in Midwest power plants that release sulfur dioxide into the atmosphere, where it turns into sulfuric acid. Lesser villains are nitrogen oxides (mainly from vehicles) that also turn into nitric acid in the air. [text continued on page 122]

By the Sixties, these pollutants had increased the natural acidity of rain to the point that trees at high altitudes in U.S. forests---including the Blue Ridge Mountains---and in similar woods across Europe were dying in clumps. Some lakes became too acidic for fish to live in. But the 1970 Clean Air Act forced new U.S. power plants to control sulfur emissions. Two decades later, tougher controls were adopted. So far, these efforts have cut acid rain by more than half---at about a fifth of the cost that power producers once predicted. We're not home free, but we're getting there.

Reversing global warming is still more problematic. Mending the ozone layer was largely a matter of switching from chlorofluorocarbons to other, more benevolent products. But the prospect of dramatically altering world energy use to correct something that at first glance seems like a tiny change in climate has some critics predicting crippled national economies and the loss of a billion jobs.

Herding the Cats

One big question now is whether we have time enough to figure out what we've already done, much less fix it. And you get a lot of different answers to that. As A.E. "Sandy" MacDonald, director of the Forecast Systems Laboratory of NOAA, puts it, "One of the nice things about scientists is, as somebody once said, 'It's like herding cats. They don't all do the same thing.'"

Boulder, Colorado boasts one of the largest concentrations of climate scientists in the world. And they are like cats, independent and contrary. The National Center for Atmospheric Research is a major power in climate debate. NCAR scientists study both climate and weather. The shorthand distinction is that climate is what we expect; weather is what we get. Climate is the long-term condition; weather is what's blowing at you at this moment. At NCAR, and with most mainstream climatologists around the world, global warming is no longer in question.

"Even the skeptics say there will be warming," explains Kevin Trenberth, a New Zealander who heads the climate analysis section that studies past, present and future changes. He considers himself a moderate in the greenhouse battles, which gives his views a distressing edge. "What we've already done," he says carefully, "is going to have major ramifications for the next 50 or 100 years."

Trenberth wrote part of a landmark report for the United Nations' Intergovernmental Panel on Climate Change, a group that has been thrashing out common ground on warming. Based on the work of 2500 researchers, the IPCC's report suggested there is a "discernible human influence on climate." For a group that, as Newsweek put it, "can hardly agree on what to order for lunch," it amounted to the heavy artillery issuing a greenhouse warning.

The group also agreed that this rate of warming is greater than the planet has seen in the past 10,000 years and could bring complex changes in the weather. Agricultural output could shrivel or prosper, depending on location. Changes in rainfall patterns and glacial melting could affect where we get our drinking water. Some forest species will likely die out; others will expand. The oceans, which have already risen more than six inches in the past hundred years, could be higher by a couple of feet a century from now---depriving the Dutch of as much as six percent of their land, Bangladeshis of almost 18 percent.

This year's EI Niño by itself raised the sea level along the California coast six to eight inches. Trenberth points out that a rise in sea level does damage not only with gradual flooding but with surges caused by hurricanes and other strong ocean storms. "Even a relatively modest increase in sea level," he says, "can suddenly scour out a whole harbor or beachfront."

Last December, in Kyoto, Japan, an international summit reluctantly agreed that the industrialized nations as a group must lower greenhouse gases to five percent below their 1990 levels by the year 2012. But the pact---if ratified by the industrial nations that signed it---will slow, not reverse, the buildup of greenhouse gases.

Meanwhile, to advocates of the greenhouse theory, new research has added more evidence of global warming. NOAA calculates that the occurrence of heavy precipitation has been up by 20 percent during this century. In July 1996, scientists at the Scripps Institution of Oceanography confirmed that spring now appears a full week earlier in the northern hemisphere than it did just two decades ago. Boston University researchers estimate that since 1980, vegetation above the 45th parallel has increased by ten percent---stimulated by warmer temperatures. Another NOAA study last year found that warming had increased atmospheric moisture---the raw ingredient of big rainstorms---by ten percent in North America.

Grisly stuff, these observations. And based on hard data. Much weather observation is simple and easily proved. For instance, real people with real glass flasks measure the increasing levels of carbon dioxide and other greenhouse ases in our atmosphere.

But theorizing about how the earth will behave under greenhouse stress---or whether that stress will be easily overwhelmed by larger climatic changes---is a different story. Global warming differs from other environmental issues because there could be winners as well as losers. Some countries stand to gain, mostly through improved agricultural production. Even within the same region, farmers may be happy to get more rain while merchants and flood-control managers pray for it to stop. And countries that make their money selling coal and petroleum face a difficult policy consideration. Saudi Arabia and Kuwait, for instance, have issued few global warming warnings, for the likely cure would be to use less of their national product.

Can the Earth Heal Itself?

In the Seventies, a couple of biologists sketched out a way of looking at the earth that has since been embraced by crystal gazers and other less-sophisticated students of the planet. The Gaia theory (or Gaia metaphor) holds that the world operates as if it were a living organism. To the embarrassment of many scientists, some took this to mean that Mother Earth is, in fact, an organism, which is not what the scientists had in mind. The real point is that the interlocking natural systems of the planet include feedback systems that tend to adjust to change in a giant mode of self-regulation.

Lee Klinger, a staff scientist at NCAR, gives an example. A rock and a rabbit start out in early summer side by side. As summer progresses and the atmosphere warms, the rock heats up steadily---a non-Gaian reaction. The temperature of the rabbit doesn't increase. The rabbit sheds some fur and spends more time in the shade to keep a constant internal temperature---that's self-regulation.

Klinger and others think such feedback systems on a world scale could account for some anomalies in global warming. With people pumping so much carbon dioxide into the atmosphere, for instance, there should be a lot more carbon hanging around than there is. Widely suspected areas for the "missing" carbon include the forests and peat bogs of the northern hemisphere. One plausible explanation: Plant growth is stimulated by carbon dioxide in the air, and this causes the plants to absorb even more CO2. Has a natural feedback mechanism kicked in to absorb the higher amounts of carbon dioxide, slowing the expected greenhouse effect?

Klinger and others agree that such [continued on page 210] Weather [continued from page 122] feedback systems could give us more time to figure out global warming, and to adjust to it. But Klinger isn't convinced that global warming is happening at all. While some areas are warming, other sites---including the Mountain Research Station of the University of Colorado, in the hills he can see through his office window---have registered a cooling trend over the past 40 years. He thinks we may have jumped the gun on global warming.

"Whether the whole world is warming or cooling is not known," says Klinger. "And I suspect it's cooling in the long run." But these are risky views among mainstream scientists. "I'm most bothered by the implication that if you don't believe in global warming, you're not a respectable scientist," says Klinger.

The Minority View

The 100-inch telescope at Mount Wilson is a classic, high in the peculiarly clear air above Los Angeles' smog. The mirror was cast from recycled wine bottles at the same French factory that once produced the Versailles mirrors. The simple bentwood chair from which Edwin Hubble discovered that the universe is expanding---the core idea of the Big Bang theory---is still in place. Sallie Baliunas, an astrophysicist from the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, has been using the telescope to study stars that act like our sun. And she thinks that the sun is doing more to warm the planet than people give it credit for. This would mean that fossil fuels are doing less.

Most scientists believe that the sun is basically stable and therefore a powerful but little-changing influence on climate. It wasn't until the late Eighties that scientists began to realize that the sun's energy output varies---if only by a tenth of one percent over a decade.

Baliunas admits, "Climate people say, and rightly so: 'It's a couple of sneezes to the climate system. It's not really worth fussing over.'" But what they miss, she says, is that the sun's energy has varied even more in the past. She cites a 70-year period during the 17th century known as the Little Ice Age. "There has been some recent global warming, but it looks like it's mostly natural," she says. "If there is a human effect, it's quite small."

That assessment aligns her with scientists who say we needn't rush to change the way we use energy. This includes Richard Lindzen, an MIT meteorologist who contends that any warming from increased carbon dioxide is well within the climate's normal range. Two chemists at the Oregon Institute of Science and Medicine contend that lusher vegetation from higher carbon dioxide levels will actually be a boon to future generations. In agreement are two think tanks, the libertarian Cato Institute and the George C. Marshall Institute, as well as Global Climate Coalition, a group largely supported by the fossil-fuel industry and many of its biggest customers.

Many skeptics, in fact, read temperature data from satellites as indicating that, over the past two decades, the world has been cooling---and that global warming predictions are just plain wrong.

It's a bitter fight. Trenberth, at NCAR, describes these opponents as "contaminated by vested interests," and says they are "very selective" in their use of data. The skeptics fire back that all scientists get funding from somewhere, including government scientists who get more research money when the public thinks it's facing a major crisis. "Everyone has an agenda," notes Baliunas.

Greenhouse skeptics have particularly argued with James Hansen, director of the Goddard Institute for Space Studies in New York and the best-known proponent of the global warming theory.

"It's normal in science to have a broad range of perspectives on any problem," Hansen says. And he agrees that studying the sun's changing energy is "a very legitimate research topic. I think the sun is one of the factors that influence climate. But it's certainly small compared to the impact, especially the eventual impact, of greenhouse gases."

Are we too Late to do Anything Useful?

If there is global warming, it can be slowed. Many scientists argue that we should have started reducing our consumption of fossil fuels long ago. Even a modest increase in the gasoline tax would encourage the use of alternative energy. These technologies could be exported to an energy-hungry developing world---particularly before that world builds more coal-burning power plants. Energy conservation would also help---from tightened standards for the average miles-per-gallon we get from our cars to wearing a sweater during winter. So would planning help some of the losers in the global warming lottery, especially those with equatorial rain forests to preserve.

"We can't say with certainty what will happen in the future, much less what will happen if we change something now," says Thomas Conway, a NOAA research chemist in Boulder who tallies the steady rise in carbon dioxide around the world. "But certainly it would be in our interest to reduce the rate of carbon dioxide being emitted into the atmosphere. That will give us more time to adjust to whatever changes may occur."

And many other scientists call for a relatively easy task: Put a little more money into finding out what's really going on.

"One of the cheapest things we can do is simply to monitor what's happening to the climate," says Karl. He notes that while existing equipment gives reasonable information about some changes, we can't get solid data on changes in such extreme weather events as tornadoes, hail, high winds and thunderstorms.

Roger Pielke Jr., an NCAR scientist who specializes in public policy, agrees we need better monitoring. He has been studying extreme storms---hurricanes, floods and blizzards among them. The global warming debate has been misconstrued, Pielke believes, into "global warming: yes or no?" He suggests that even if global warming were not an issue, 95 percent of our climate and weather-related problems would still be with us and worth doing something about. "We don't know how many people live in floodplains in the U.S.," Pielke says, "so we don't know how vulnerable we are to floods. If you say it's going to get worse, we should know how bad it is already."

If we assume global warming is going to occur, Pielke says, we'll have floods, blizzards and hurricanes. "And if we assume that it's not going to occur, we will still have floods, blizzards and hurricanes. Those are going to persist throughout time."

"Even a relatively modest increase in sea level can suddenly scour out a whole harbor or beachfront."

So, What's Behind All Thie Weird Weather?