Al Gore must step out of his role as influential statesman, realize duty calls and enter the 2008 race for the presidency.

Gore has shown in recent years how determination can make a difference. And his determination could find no better outlet than helping this nation regain its world leadership role, especially in the face of this aging planet's most insidious threat: destruction by humanity's ever-growing burden on the environment.

Gore knows the danger well. His focus on this planet's fragile environment and how global climate change has been affecting it has created the awareness needed to understand the problem.

Gore has not been the sole messenger of this threat, merely the most visible. Many scientists, including biologist E.O. Wilson, have long warned of the dangers faced. Wilson, interviewed Friday on "Bill Moyers' Journal," put the danger into precise terms.

"This is the only planet we're ever going to have," he said. He called the natural environment that has taken hundreds of millions of years to create, "our greatest natural heritage. And we're throwing it away in a matter of a few decades."

Gore has been bringing this message to the masses through his film, "An Inconvenient Truth," and in his sponsorship of the 24-hour "Live Earth" concert that spanned the globe over the weekend.

But it takes more than a film and a worldwide concert to bring about solutions — it takes leadership to marshal the best talents and the most creative thinkers, things many nations have in abundance, to move from problems identified to solutions found.

As Gore told the "Live Earth" audience Saturday in Giants Stadium in East Rutherford, N.J.: "Times like these demand action."

But the need has gone far beyond asking people to do their part in cleaning up the environment, in reducing their carbon footprints, in creating an Earth that will sustain future generations.

The problem has grown so large in scope, it requires action on a national scale. Only the full force of government can bring about the necessary mobilization of technology, talent and incentive to address the problem. It requires a mobilization akin to the way this nation roused itself from isolationist slumber after Pearl Harbor. It requires implementing goals akin to President Kennedy's calling for this nation to send a man to the moon and return him safely, a feat accomplished in less than eight years.

Gore has earned the right to issue the challenge. But this is not merely a national problem. All nations must work in conjunction with each other to save planet Earth.

The next president must be, above all else, a statesman whose vision extends well beyond this nation's border, one who understands how to work with and not browbeat foreign leaders and one who will seek a consensus with other nations and not demand they slavishly bend to this nation's will.

It cannot be said too often: Saving the environment has become the greatest task facing this world today.

Yes, other issues large and small will face whomever becomes president and the foreign leaders with whom he or she will interact. External threats exist that require strong security measures. Poverty and hunger continue to be twin plagues in a world of plenty. The war in Iraq has destabilized much of the Middle East. And no one can predict what might happen — good or bad.

Yet, by failing to focus a lion's share of attention and efforts on restoring and protecting the environment, people run the risk of something far worse than a terrorist attack, an impoverished nation, upheaval in the Middle East — they run the risk of losing all life.

Yes, money, lots of it, will need to be spent to repair man's damage to this planet. But it does bring a return.

Species that thrive in an ecosystem provide services to humanity such as pollination and water purification. Wilson told Moyers on Friday the true value of these services:

"We get from nature scot-free, so long as we don't screw it up and destroy it, approximately the same amount of services, as far as you can measure them in dollars, we ourselves produce each year. It was about $30 trillion a year."

By damaging the ecosystem, Wilson said, humanity brings about the conditions that destroy valuable species, weakening an ecosystem and making it less likely to rebound after a disaster.

Humanity has been damaging the ecosystem and placed itself in a life-and-death struggle. Action must begin now.

On stage Saturday in New Jersey, Gore asked audience members to commit themselves to a seven-point pledge that includes urging a moratorium on new coal-powered plants and an increased effort to find more renewable energy.

"I would like to ask each and every one of you to answer the call," he said.

Gore has issued his call. Will he heed the nation's call?

— Richard Larsen is a deputy opinion page editor at The Star. His e-mail address is rlarsen@VenturaCountyStar.com.