Climate Change and Environmental Surprises Ahead

{Ed. Note: This second part of a two part series on the Worldwatch Institute's "State of the World 2000" issued this week predicts not only global warming but a cascade of unexpected environmental effects from the warming planet. See part one for Population and Diminishing Resources.}

By Cat Lazaroff

WASHINGTON, DC, January 19, 2000 (ENS) - Glaciers are melting. Where once snow fell, now only rain pounds down. Storm systems driven by tropical heatwaves are getting stronger, and more deadly. Increasing amounts of greenhouse gases are being pumped into the atmosphere, and as a result, temperatures around the globe are rising.

A blue ribbon panel confirmed it last week - global warming is real.


Glaciers and ice packs are retreating around the world (Photo courtesy National Park Service)
"The two big challenges in this new century are to stabilize climate and population," said Brown at a press conference Thursday. "If we cannot stabilize both, there is not an ecosystem on Earth that we can save. Everything will change. If we can stabilize population and climate, other environmental problems will be much more manageable."

"When the industrial revolution began more than two centuries ago, the carbon dioxide (CO2) concentration was estimated at 280 parts per million (ppm)," writes Worldwatch Institute president Lester Brown in the groupís latest roundup of environmental problems, "State of the World 2000."

"By 1959, when detailed measurements began, using modern instruments, the CO2 level was 316 ppm, a rise of 13 percent over two centuries. By 1998, it had reached 367 ppm, climbing 17 percent in just 39 years. This increase has become one of Earthís most predictable environmental trends," Brown wrote in the the Worldwatch report.

But the steady rise of CO2 has had numerous unpredictable side effects - some of which threaten to become catastrophic. Over the last three decades, global average temperature has risen by 0.44 degrees Celsius (0.8 degrees Fahrenheit).

In the 21st century, temperature is projected to rise even faster.


Chris Bright, coauthor of Worldwatch's "State of the World 2000" report (Photo courtesy Worldwatch Institute)
"Just because we think we know what the trend is right now, that doesnít mean it will stay on the same curve," said Chris Bright, coauthor of the Worldwatch report. "Weíre not very good at predicting the discontinuities."

Signs of melting are everywhere. In late 1991, hikers in the southwestern Alps discovered an intact human body protruding from a glacier. The man was apparently trapped by a storm some 5,000 years ago, and rapidly covered by ice and snow, remaining remarkably well preserved. In 1999, another body was found in a melting glacier in the Yukon Territory of western Canada.

"Our ancestors are emerging from the ice with a message for us," said Brown. "The Earth is getting warmer."

Rising temperatures are shrinking glaciers from the Peruvian Andes to the Swiss Alps. The two ice shelves on either side of the Antarctic peninsula are retreating. Over about a half century through 1997, the ice shelves lost 7,000 square kilometers (2,700 square miles) of ice.

Then, within a single year, the ice shelves lost another 3,000 square kilometers (1,160 square miles). Scientists attribute the accelerated rate melting to a regional temperature rise of about 2.5 degrees Celsius (4.5 degrees Fahrenheit) since 1940.

"Environmental decline is often seen as gradual and predictable, but if we assume this, we are sleepwalking through history," said Bright in the Worldwatch report. "As pressures on the Earthís natural systems build, there may be some disconcerting surprises as trends interact, reinforcing each other and triggering abrupt changes."


Aerial view of the eye of Hurricane Mitch. (Photo courtesy PAHO)
In October 1998, Hurricane Mitch slammed into Central American and stalled there for more than a week. Mudslides obliterated entire villages, killing some 10,000 people. Half the population of Honduras was displaced, and the country lost 95 percent of its crops.

Bright says global warming and the more destructive storms associated with it may explain why Mitch was the fourth strongest hurricane to enter the Caribbean in the 20th century. However, much of the damage left by Mitch was triggered by deforestation. If trees had been gripping the soil on those hills, less mud would have slid precipitously down their slopes.

Another large scale example of trends reinforcing each other can be seen in the Amazon River Basin, where the forests are being weakened by logging and clearing for agriculture. Openings in the canopy let in more sunlight, which dries the forest floor and primes the area for fire. Fires sweep through the forest, damaging trees but leave many standing. These damaged trees drop more leaves and exhale less water, inviting more fire in what Bright calls a "fire feedback loop."

"A great deal of the damage is hidden beneath the forest canopy," Bright said. "Itís kind of like a cancer. In its initial stages, you really canít see it."


Ground fire in the Brazilian Amazon. (Photos and map courtesy Woods Hole Research Center)
The fire feedback loop is also affected by forces outside the region, such as higher temperatures and harsher weather brought on by greenhouse gas emissions. The worst burning, Bright points out, occurs in El Nino years - which are happening more frequently as temperatures rise. El Nino is a warming of the Eastern Pacific Ocean that results in climate changes around the world.

By burning large amounts of coal and oil, the U.S., China and other industrialized countries may, in effect, be burning the Amazon, Worldwatch warns.

"We have no way to repair these systems," said Bright. "Nature has no reset button."

Dr. Jane Lubchenco, a marine conservation biologist specializing in the consequences of global changes, spoke last month about the devastating changes happening in ecosystems worldwide. "Weíre changing the planet in unprecedented ways," said Lubchenco. "About one half to one third of the landís surface has been transformed. One third of commercial marine species are depleted or fully exploited. The functioning of these ecosystems in changing, sometimes dramatically."

Coral reefs, for example, are showing dramatic and unexpected impacts from both global warming and human actions. While warmer waters has allowed some corals to spread away from the equator, water that is too hot seems to be killing off some of the microscopic creatures on which corals feed, starving them to death.

bleached coral

Coral bleaching is a sign of the worldwide decline of corals (Photo courtesy Florida National Marine Sanctuary)
In other areas, fungi that thrive in warmer waters are gaining a foothold on corals and killing them. Algae blooming in nutrient rich runoff can starve corals for light. "Pollution enriched algae is the likely reason Jamaicaís reefs never recovered from Hurricane Allen in 1980," writes Bright in the Worldwatch report. "Ninety percent of the reefs off the islandís northwest coast are now just algae covered lumps of limestone."

Worldwatch urges action now to stem the tide of environmental catastrophe.

"We clearly need to step up the pace," Brown said. "We are running out of time. The decisions we make now will affect life on Earth for all time to come."