*DARK FORCES OF HUMAN OVERPOPULATION*

BEFORE the environmental activist and gay rights lawyer David Buckel set himself afire in Prospect Park in Brooklyn on April 14 -

He wrote a letter explaining that he had chosen his ''early death by fossil fuel'' as an act of protest against the environmental catastrophe that we are bringing on ourselves and the planet.

It was a horrifying end, not least because in life Mr. Buckel had successfully taken on issues as  seemingly intractable as the legalization of same-sex marriage.

If someone so capable had given up on the environment, one woman remarked to a Times reporter, ''What does that mean for the rest of us?''

I was thinking about Mr, Buckel and about despair a few nights later, over a drink with Joe Walston of the Wildlife Conservation Society.

As a director of that organization's worldwide  field conservation work, Mr. Walston routinely comes face-to-face with-

Dark forces of . human overpopulation, mass extinction of species, climate change and pollution. But he is also the co-author of of paper being published this week in the journal BioScience that begins-

With the uplifting words of Winston Churchill to the British nation in June 1940, under the shadow of the Nazi conquest of France.

''In casting up this Dread Balance Sheet and contemplating our dangers with a disillusioned eye,'' Churchill declared, ''I see great reason for intense vigilance exertion, but none whatever for panic or despair.''

Mr. Walston and his co-authors go on to argue against the increasingly common view that these are the end times for life as we know it.

Instead, they suggest that what the natural world is experiencing is a natural bottleneck -

Long, painful, undoubtedly frightening and likely to get worse in the short term - but with the forces of a eventual breakthrough and environmental recovery already gathering strength around us.

Mr. Walston sipped his drink and listed what he called the......

The Operational Research and Publishing continues to Part 2. And the World Students Society thanks author and researcher Richard Conniff.