Not long ago, the New York Times columnist Thomas Friedman took a break from his analysis of world affairs and went to Machu Picchu in Peru to have a look at the Andes Mountains. According to his column filed that day, Mr. Friedman was troubled by what he saw. The mighty peaks surrounding Machu Picchu, once described in guide books as “snow capped,” are now merely “snow frosted,” he tells us. Not only is the snow disappearing from the mountains, but a whole cascade of calamities is now about to descend on this vulnerable mountain community. The giant white corn is getting smaller because “the water level is going down, and the temperature is going up.” Precious and unique species of plants and animals are threatened with extinction because the boundaries between mountain climate zones are beginning to change. The very fabric of this community is unraveling and the culprit is global warming, the great ecological disaster that has now replaced the Population Explosion in the fevered imagination of the eco left.

Elizabeth Kolbert’s jeremiad on climate change, called “Field Notes From a Catastrophe”(Bloomsbury, 210 pages, $22.95) takes a similar position.Written in the colorful style for which the New Yorker magazine is famous (“Field Notes” first appeared there), the book combines chatty personal details with a mind-numbing avalanche of factoids. Like Mr. Friedman, Ms. Kolbert is concerned about the effect of global warming on creatures large and small. Whole chapters are devoted to the migrations of a certain mosquito and the Comma butterfly (Polygonia c-album), both of which are apparently moving further north than usual. Various important frogs are going extinct. In her patient, if tedious, style, Ms. Kolbert heaps up her mountain of evidence, combining selective scientific material with folksy anecdotal observations.

What, then, is her fundamental point of view? Reduced to its essentials, it could be summed up as follows: 1.) The climate has been stable and is not supposed to change; 2.) If the climate does change, it is man’s fault; 3.) Actually, it is the Americans’ fault, which means George Bush. This summary applies equally to “The Weather Makers: How Man is Changing the Climate and What It Means for Life on Earth” (Atlantic Monthly Press, 358 pages, $24) by Tim Flannery and to “An Inconvenient Truth” (Rodale, 328 pages, $21.95) by Al Gore. These writers, including Mr. Friedman, are members of that Herd of Independent Minds that view the matter through the same politicized lens. For this group, global warming has emerged as a key political issue both to rally support for the greens and to attack conservatives. The question is how valid are their basic assumptions?

To begin with, it is an inconvenient truth that the climate on this planet is always changing. On a large scale, this change is sometimes very slow (the early Jurassic, for example) and at other times it is much faster, as we have experienced during the current glacial-interglacial cycle. More important, however, is the growing awareness that, despite relative stability for the last 10,500 years, climate can change very fast and very suddenly on a much more local scale, and has done so many times in the past. Evidence of these events is turning up in ice and sea core drilling experiments, ocean coral analysis, and even archaeology. Nevertheless, the books under review here all share the underlying assumption that our climate is static and, if left alone, will not change. Since any recognition of the climate’s chronic instability would dilute their essential point that everything is man’s fault, the left persists in clinging to its mythic paradigm of Man vs. Nature. It would be useful to understand the origins of this mythic framework, and a good place to begin is to visit the Garden of Eden. Literally.

Beginning around 10,500 years ago, the Sahara Desert of North Africa became lush and moist with abundant lakes and sufficient rainfall to support a very large population. This was an ideal human environment — the real Garden of Eden — and it lasted for approximately 5,000 years. Then suddenly it all came crashing down. Practically overnight the rainfall ceased and the population was driven out — much of it toward the Nile. This massive calamity was inexplicable to these people, and the deep trauma of it left an indelible mark on the psyche of the West that will remain with us forever in the story of Adam and Eve. Here is one source of the mythic template used by the eco left to account for the climate change we may be confronting now: It must be our fault — we have sinned and we must be punished. They cannot grasp the true significance of this story, namely that in the real world, Mother Nature can sometimes be very nasty indeed, all by herself, unprovoked, regardless of what man is doing or not doing. For hundreds of thousands of years, man has had to deal with such climate crises, large and small, and very often his mythological explanation was to blame himself. Now we need to remember what these lessons from the past teach us: The world’s climate is profoundly unstable and the moralizing template may not apply.

What about the second premise of the global warming zealots, namely that the earth is getting warmer and it’s man’s fault? This is the main thrust of all four of these books. A straw man has been set up who denies global warming and man’s role in it. These impassioned warriors are determined to strike him down. Hence we have pages of graphs, diagrams, and foldouts demonstrating the inexorable rise of temperatures as a consequence of our burning fossil fuels, the greenhouse effect, the coming calamity, etc. This is the eco religion in all of its passionate fervor. In their haste to politicize the issue, reasonable and cautious science gets trampled. The main problem is not whether man has caused some global warming — it would be surprising if he had not — but how much, how fast, and how does this factor correlate with the climate’s own inclinations.

The key scientific question is to understand how the climate works. This is a much more complicated issue than these apocalyptic volumes concede. The tendency to write catastrophic headlines sells books but does not advance the science, and without better science, it is impossible to know exactly what should be done, if anything. The important point is to realize that it makes no difference at all what has caused global warming, if it is occurring. Since man is part of the planet’s biomass, what he does becomes a natural part of the global ecology. He cannot be viewed as an alien, outside influence who has sinned, like Adam.

This is a concept difficult for these authors to grasp, committed as they are to the view that man is a pollutant always upsetting the delicate balance that earth, or “Gaia,” has so carefully created. Although James Lovelock’s entrancing and romantic notion in “The Revenge of Gaia” (Basic Books, 178 pages, $25) of “Gaia” as a wonderful world always adjusting itself to keep everything humming just so, has found an impassioned following in some of the kids handing out literature around Washington Square, it lacks serious scientific content. There is, in fact, no actual balance in the earth’s ecological setup, and there never has been.All is change, flux, and Darwinian adaptation. The shifting habitats so deplored in all of these books in fact describe the way the world works.

So, are we doomed to extinction as these authors are trying so hard to convince us? If the CO 2 levels are indeed rising and the world is getting warmer, the only question that matters is: What are we going to do about it? The planet itself is completely indifferent to our fate; global warming does not concern the planet — it concerns us.If there were another scenario at play here, namely an oncoming ice age, we would be confronted with exactly the same dilemma: What should we do?

This is where we see the greatest failure of the eco left. Gifted as they are in apocalyptic hysteria, there is very little effort to come to grips with real solutions to the problem, whatever its extent. Here is Ms. Kolbert’s final sentence: “It may be impossible to imagine that a technologically advanced society could choose, in essence, to destroy itself, but that is what we are now in the process of doing.” Really? Because we have rejected the totally useless Kyoto Protocol, does that mean there is nothing to be done? Nonsense.Yet these authors are diffident and weak on the question. Not interested, really. The exotic wind farms and solar panels they prefer are not serious solutions, and neither are conservation programs — ban sport utility vehicles, back to bicycles, walk more, etc. The problem is to understand what is happening, without hysteria, and then try to formulate a response that is actually doable in the real world. There are steps that could be taken to lower CO2 emissions, although these are complicated and controversial. To begin with, there is no real energy crisis. If it turns out that burning fossil fuels is a bad idea (or the supply is choked off by our buddies in the Middle East), the market will produce alternatives if allowed to do so. Hydrogen fuel cells are only one of many proposals now being developed. Above all (as most serious scientists agree), the nuclear fission industry must be revived if we hope to reduce our carbon dependency. Incredibly, there is no mention of this possibility in Al Gore’s tendentious, mawkish, self-aggrandizing embarrassment of a book.Al Gore does not understand that man is not the problem, man is the solution. Having politicized this issue for his own political benefit, he has nothing of real interest to say about it.

Finally, global warming is not George Bush’s fault. It is a natural consequence of man’s incredible progress on the planet. Repeatedly, this progress has brought us into conflict with the oscillations of the world’s climate, and this will continue forever. Man will not retreat back into some long lost Eden. Rather, he will continue to expand his world through technology and creativity, and it will be these tools that he will use to deal with either global warming or some other climactic calamity, which will doubtless confront us. When faced with climate change, all organisms have the choice to adapt, move, or go extinct. Only man has a fourth option: Challenge the climate and change it.

Mr. Pettus last wrote for these pages about cloning.