In the world of environmentalism, things can often seem rather bleak. Rare species from Barrow to Borneo are likely going extinct before they are even discovered. Rain forests are shrinking. Greenhouse gases, it sometimes seems, are turning the atmosphere into a giant toaster oven.
Then came the news late last month: According to Australian scientists, the hole in the ozone layer a symbol of human environmental destruction so universal that it became the punch line in an Austin Powers movie will begin closing in three years. Thanks to international efforts to ban certain chemicals, the opening would shut by 2050.
In light of the sense of approaching apocalypse on many conservation issues, this is a success story more common than many people might expect. It highlights a history of progress on some of the most serious environmental problems of the past 30 years from clean air to panda bears.
The progress is far from complete. Environmental threats are perhaps more varied and widespread than they have ever been. Yet the success in the atmosphere above Antarctica, and improvements in several other areas, suggests that when the global community identifies a problem and unifies behind a solution, it can reverse even the most dire environmental disasters.
The success of some international environmental measures often receives little attention. Indeed, the ozone reforms could provide at least a framework for how to move forward on the first great green issue of the 21st century: climate change.
"It's an untold story," says Daniel Esty, a professor of environmental law at Yale University in New Haven, Conn. "It's a good example that well-designed programs can work."
Strictly speaking, the news that the ozone layer is on the mend is not a surprise. The timeline fits nicely with the one laid out by the Montreal Protocol, which in 1987 required nations to cut their use of chorofluorocarbons (CFCs), the chemicals causing the problem.
In an unrelated but confusing development this week, American scientists say the ozone hole is currently 88 percent smaller than normal. But that's a function of unusual weather, and scientists expect the hole to expand again.
By contrast, the gradual and human- induced shrinking of the hole reported in the Australian study is permanent, and in that respect, more significant. It is further confirmation of a surprisingly positive global track record on the environment one that is often lost amid the desire to point out how bad things are, rather than chronicle how much better they have gotten in recent decades.
As an example of the nationwide improvement in air quality, experts note that Los Angeles this year enjoyed its third consecutive summer without a single smog alert. (In the 1970s, 80 alerts a year were not unusual.) They suggest that the international campaign to save the whales saved the whales, that global bans on chemicals like DDT revitalized bird populations like the bald eagle, and that acid rain has been cut by more than half in Europe and the United States during the past few decades.
Activists will gladly and rightly proclaim that a phalanx of other issues from biodiversity to fishing rights has either been largely ignored by the international community or mangled by less successful regulations. But many domestic and international programs have "absolutely" had a significant impact on the environment, says Karim Ahmed of the National Council on Science and the Environment in Washington.
The Montreal Protocol "is the most dramatic example," he adds, and it offers insight into how and when environmental reforms are successful.
For one, there needs to be a crisis that grabs the public's attention and scientific proof of it, whether it's a decline in cuddly Chinese bears or a rise in lead poisonings.
When two scientists in 1974 posited that CFCs were eating away at the ozone layer, which protects the Earth from the sun's ultraviolet rays, a few companies discontinued offending aerosol cans, but the reaction was muted. In 1985, however, researchers looked at the Antarctic atmosphere and found that CFCs were thinning a massive section of the ozone layer. Suddenly, public health always the greatest motivating factor in environmental reform was at risk, creating a sense of urgency.
The Montreal Protocol followed, and businesses, which had estimated that the cost of phasing out CFCs would be devastating, were pressured to find economic alternatives and did. "Once industry, science, and politics got together, it started to move quickly," says Stephen Andersen, author of "Protecting the Ozone Layer." "It turned out to be fairly painless."
To some, there are clear parallels between the emergence of the problems with the ozone layer and the current questions over global warming. If science does prove a significant link between greenhouse gases and global warming and can show how that is hurting humans many expect a similar sort of urgency to follow.
But many of the similarities end there. Global warming is representative of the new environmental challenges of the 21st century, says Dr. Esty of Yale. The broad reforms of the 1980s and '90s went a long way toward cleaning up the biggest polluters. Now, global warming and other issues will have to take the fight to the ordinary modern citizen.
"The scale of this issue is 500 million times more complicated," says Esty. "You're implicating every business, every family that drives an automobile."