Are We Ignoring the Early Warning Signs of Global Warming?
Pasqual Gorriz / AP Wide World Photos
Could bad weather be more than bad luck? Were the droughts, disease outbreaks, wildfires and floods brought on by the great El Ni?o weather event of 1997-98 more than just the chance result of our variable global climate? The severity of this last El Ni?o event has some climatologists wondering if human-caused global warming might not be partly responsible for the severe weather.
El Ni?o is a buildup of warm water in the eastern Pacific which recurs every three to eight years, producing a variety of severely disruptive weather patterns across the globe. Kevin Trenberth of the National Center for Atmospheric Research says he sees more than naturally occurring weather forces at work now, though. “El Ni?o’s been behaving in a strange fashion over the last 20 years,” Treberth says, “and this last El Ni?o event was massive—the sea surface temperature anomaly was bigger than we’d ever seen before in previous El Ni?os, nine degrees Fahrenheit above normal. That’s an extraordinarily large number, considering it held there for two or three months.”
Not only was 1997 the warmest year on record, and the first half of 1998 even warmer, but also nine of the 11 hottest years of the century fell within the last decade. The mounting evidence for global warming includes rising sea levels (six inches in the past 100 years), widespread glacial melting and an ever-closer fit of observed trends with computer-generated climate models.
One such model’s results, reported in 1996 in Nature, reveal that climate-change patterns resulting from global warming closely resemble those associated with present-day El Ni?o events in the tropical Pacific. The researchers, Warren Washington and Gerald Meehl, conclude that because El Ni?o and global warming mimic each other, it’s extremely difficult to accurately pinpoint the causes of climate disturbance.
Naturally caused or not, there is no denying the severe environmental toll of recent weather. Off California, Peru and Chile, warming of ocean waters disrupted the food chain by preventing nutrient-rich cold water from rising to the surface. This caused zooplankton to die out, in turn starving sea lions and other marine mammals. Higher sea surface temperatures caused by El Ni?o are also alleged to be killing off coral reefs around the world. (Warm waters contributed to coral bleaching events in the Florida Keys in 1980, 1983, 1987 and 1990.)
In Indonesia, rainforest fires torched more than 6,000 square miles, imperiling many rare species including plants, tropical migrant birds, leopards, tigers, elephants, rhinoceroses and orangutans. Fernando Gonzales, a World Wildlife Fund (WWF) staffer who was stationed in Indonesia, observes, “People were lighting fires [to clear land], thinking the rains would come soon, as they always had.”
The economic damage caused by of the Indonesian fires and smoke amounted to more than $4.4 billion, according to a joint study by WWF and the Economy and Environment Program for South East Asia (EEPSEA). The Worldwatch Institute also reports that the 1997 fires in Asia alone released about as much carbon into the atmosphere as all of the factories, power plants and vehicles in Western Europe do in a year.
Earlier this year, the Indonesian scenario repeated itself in Mexico and Central America, with more than a million acres of grasslands and forests burned. Smoke from the fires actually covered the entire sky over much of Texas, more than 1,000 miles away, for several weeks. Texas health authorities warned people to stay indoors and avoid heavy exertion while the smog-like haze lingered. The greatest concern for human health was the inhalation of tiny particles, many of them cancer-causing. Haze from the fires was reported as far away as Denver and Chicago.
Last year in Brazil, the Amazon basin’s treasure trove of biodiversity was singed when an area the size of Great Britain went up in flames. Members of a Stone Age tribe, the Yanamamo, lost their homes to the raging inferno.
El Ni?o’s damages, and global warming’s as well, are not limited to droughts and fire. Some places also receive more water, with devastating floods and ferocious storms. Trenberth says, “You do expect in a general sense, an enhanced hydrological cycle—more evaporation, more moisture in the atmosphere, more rainfall. Rainfall by its very nature tends to be spotty, so places where it rains, [it] rains harder, and places where it doesn’t rain, the droughts are apt to be worse. In the U.S., there are pretty good measurements of rainfall going back to 1910. There’s been an eight percent increase in rainfall in that period, but the key thing is that all of the increases have occurred at the high end—when it rains, it rains harder. This is what you’d expect from global warming.”
Floods attributed to El Ni?o made as many as half a million people homeless in Burma. In California, a barrage of mudslides and storms caused a state of emergency in 31 counties, with eight deaths and power blackouts in tens of thousands of homes. In Mexico last October, more than 400 died due to Hurricane Pauline. Typhoon Winnie, the most powerful in decades, killed 43 in China and Taiwan.
Hurricane Linda in the eastern Pacific was the strongest ever recorded. A Category 5 hurricane has gusts up to 220 miles per hour, with sustained winds of 200 miles per hour but, according to CNN, Linda exceeded Category 5 by such an extent that a new Category 6 was proposed by meteorologists.
If climate experts are correct, then the latest El Ni?o effects may only be a taste of what’s to come when global warming unleashes its full disruptive power. But this idea has its skeptics, including Marlowe Lewis, vice president for policy of the Washington-based Competitive Enterprise Institute, a “pro-free-market think tank.”
Lewis says he’s “very skeptical” that the recent large fires attributed to El Ni?o can be linked to global climate change. “Any time in the world there is going to be a drought somewhere, a flood somewhere, a deluge somewhere,” he says. “Climate science is still such primitive enterprise that there’s no way to correlate any particular drought or unusually wet weather cycle with any long-range trend in the climate.” Besides, says Lewis, “There’s no particular reason to assume that a modest warming is anything to be terrified about.”
The storms ahead may lend a renewed urgency to international efforts aimed at curbing greenhouse gas emissions, but if people continue to finger El Ni?o as the sole culprit, Mother Nature’s warning may not be heeded.