Mobilizing to Combat Global Warming.

Homo sapiens has always altered its immediate environment. For example, ancient farmers converted the Fertile Crescent--the fabled Babylon--into the desert wastes of Iraq. But only in the last few decades have we had the capacity to literally change the entire planet. Only recently have we become a geophysical force.

Jane Lubchenco, the former president of the prestigious American Association for the Advancement of Science, spoke forcefully about this new phenomenon in her farewell address to the AAAS. Looking out over a sea of the nation's top scientists, Lubchenco warned:

During the last few decades, humans have emerged as a new force of nature. We are modifying physical, chemical, and biological systems in new ways, at faster rates, and over larger spatial scales than ever recorded on Earth. Humans have unwittingly embarked upon a grand experiment with our planet.

In 1992, 3,500 scientists from around the world signed a World Scientists' Warning to Humanity that stated:

Our massive tampering with the world's interdependent web of life--coupled with the environmental damage inflicted by deforestation, species loss, and climate change--could trigger widespread adverse effects, including unpredictable collapses of critical biological systems whose interactions and dynamics we only imperfectly understand.

These are not exhortations from overwrought extremists, but carefully phased warnings from some of the world's finest scientists. While the "news" is dominated by sex scandals, celebrity athletes, and car wrecks, these scholars are trying to call public attention to the fact that the world has entered a dangerous new era. A few stark examples:

* Most of the world's great biological systems are in a state of collapse because we have logged, trawled, or cultivated them to maximize short-term production. Plant and animal species are going extinct at the fastest rate in 65 million years.

* The world's existing human population is already three times as great as the planet's long-term carrying capacity if all people seek a level of affluence comparable to that currently enjoyed in, say, Sweden.[*]

* Although the Cold War is over, little if any progress has been made in removing the single most imminent threat to the global environment--nuclear holocaust. A respectable body of opinion holds that a nuclear war is more likely today than it was under Brezhnev.

* We have carved two giant holes in the ozone layer, increasing the exposure of people, plants, and animals to damaging radiation from the sun.

* We have raised the temperature of the entire planet and set in motion a series of inexorable forces that will raise it a lot more before we can bring it back into equilibrium--no matter what we do.

Solutions to these daunting problems have begun to emerge. They are opposed, however, by entrenched government bureaucrats and by private economic interests that are comfortable with the status quo and could be harmed by change.

We have no institutional framework within which to address global environmental issues. The United Nations Environmental Programme is underfunded and lacks regulatory or enforcement power. The strongest international agency, the World Trade Organization, has proven to be aggressively anti-environmental in its goals and processes.

Whenever progress has been made on a global environmental problem--such as ozone depletion--it has been due to a worldwide outpouring of public sentiment. Earth Day can be a central element in the campaign to mobilize an aroused citizenry.

On April 22 of each year, people in most countries celebrate this informal, non-governmental holiday dedicated to the environmental health of our planet. Earth Day Network plans to focus each of these annual campaigns on a major global problem, and educate people around the world about common-sense solutions.

Earth Day 2000 is focused on the peril of global warming and the need to accelerate the transition to the solar energy era. The aim is to create an informed global constituency for the super-efficient use of renewable energy sources as the best way to implement the Kyoto Protocol on Global Warming.

The global coal industry and most of the world's oil companies and electric utilities have sought to obfuscate, manipulate, spin, or crush past efforts to promote a renewable energy transition. But the science is now clear. Burning more and more carbon-based fuels into the future will produce a catastrophe.

Avoiding irreversible planetary calamity--and instead guiding human development in positive directions that are healthy, diverse, and sustainable--is the primary moral obligation of our era. This profound mission is what makes the modern environmental movement more than "just one more special interest."

The environmental movement, having enjoyed many successes at the city, state, and national levels, now needs to begin to address the global problems that threaten to undo all our progress elsewhere. Energy and climate change will be the first major test.

Denis Hayes is the international chairman of Earth Day Network (EDN) and the author of The Official Earth Day Guide to Planet Repair (Washington, DC: Island Press, 2000). EDN has more than 4,000 affiliated organizations in 180 countries.

(*.) A thoughtful study of global human carrying capacity was released in early 1994 by David Pimentel, a professor of biology at Cornell University. The good news, as Professor Pimentel calculates it, is that if the most benign and efficient technologies were universally embraced, the world could permanently support a human population of two billion people at a lifestyle that resembles middle-class life in today's Europe. The bad news is that the world's population passed the six billion mark--three times that carrying capacity--in October, 1999.