If you’ve been feeling depressed because you can’t get your anxieties prioritized–if you don’t know whether to worry first about the erosion of Chicago’s shoreline, Gorbachev’s domestic problems, or homelessness–cheer up. Global warming has come of age. It’s a kind of United Fund for angst: worry about it, and you don’t need to bother worrying about anything else.

Although a group of environmentalists has been plucking at the collective sleeve of conscience for a decade, trying to get us to see there’s a problem, the publication last fall of two books on the subject may finally bring public attention to global warming. Both Bill McKibben in The End of Nature and Stephen Schneider in Global Warming: Are We Entering the Greenhouse Century? argue that our energy-wasting life-style has already begun to produce rapid climatic change that will cause worldwide chaos.

Schneider’s Global Warming is a straight-ahead recounting of the scientific evidence, and it is balanced, convincing, and paralytically depressing. However, for sheer existential/ecological bleakness, The End of Nature puts Global Warming in a league with The Berenstain Bears Go to the Dentist.

That’s because McKibben says that, though the consequences of global warming are horrific, they pale in comparison to the spiritual crisis brought on by the end of nature as a force outside human control: “We are in charge now, like it or not,” he writes. “As species we are as gods–our reach is global. And God has not stopped us.” In his view, even if the human race were somehow to pull itself out of its environmental nosedive, nature would still be dead. “A child born now will never know a natural summer, a natural autumn, winter, or spring,” McKibben grieves.

After you regain consciousness, the question that instantly arises is: Do these guys know what they’re talking about? After all, at a greenhouse conference last June, the only statement the assembled mainstream climatologists could agree on was: “It is tempting to attribute [the 0.5 degrees C warming of the past 100 years] to the increase of greenhouse gases. Because of the natural variation of temperature, however, such an attribution cannot now be made with any degree of confidence.” Not exactly a call to arms.

So what’s the story? Are Schneider and McKibben merely alarmists, advancing their scientific and journalistic careers, respectively, by capitalizing on the Armageddon of the Month? Or do they just have enough common sense to see that by the time the scientists have dotted all the is and crossed all the ts, the moment for action will have passed?

Sad to say, I don’t think Schneider and McKibben are opportunists. Although the scientific community doesn’t speak with one voice on the greenhouse issue–or on anything else, for that matter–there is agreement on some basic facts, and they’re not cheerful.

Since the 1950s, when scientists began monitoring carbon dioxide, its levels in the atmosphere have been rising. The amounts involved are tiny; even now, levels are only about 350 parts per million, up from the 280 ppm or thereabouts thought to have been typical for the last 10,000 years or so. Carbon dioxide is an inevitable by-product of the burning of fossil fuels, and the increase in the atmosphere seems to be strongly correlated with the increased pace of population growth and industrialization.

Carbon dioxide absorbs and traps some of the heat that the earth has received from the sun and normally would radiate back into space; it really does function like the glass panels in a greenhouse. All else being equal, the more carbon dioxide we pump into the atmosphere, the more heat is trapped, and the hotter it will get. This means far-reaching and possibly cataclysmic changes in the world’s weather.

The scientific debate, simply put, boils down to three issues: Is it really getting warmer worldwide, or are the thermometers just in warm places? If it is getting warmer, is it happening unnaturally fast? Finally, are there natural mechanisms that will kick in and moderate the warming effect? Schneider answers all these questions, and he’s well-qualified to do it. He’s a climatologist with the National Center for Atmospheric Research in Boulder, Colorado, founder and editor of the academic journal Climate Change, and author of several respectable science books for laypeople, including The Genesis Strategy and The Coevolution of Climate and Life. He’s also a frequent witness before congressional committees on atmospheric issues, which gives him special expertise in the field he calls “mediarology.”

Like many books in the large and expanding eco-disaster genre, Global Warming begins with a scenario of what the world will be like if the catastrophe at hand isn’t averted. In the case of global warming, the scenario includes rising sea level, increased numbers of high-intensity storms that will ravage the coastline, drought in the continental interior, and worldwide starvation.

Although he’s one of the most vocal proponents of the idea that governments worldwide need to take action this very minute to slow down global warming, Schneider acknowledges candidly that predicting the future is a risky business. Figuring out next week’s weather is next to impossible, and predicting a global climate pattern for the next decade is correspondingly harder. The scenarios that alarm him are based on computer models, and they vary widely depending on the parameters that are built into the models. For example, nobody is quite sure how the oceans fit in: how much carbon dioxide can they absorb? (To give you an idea how fuzzy things are, Schneider once dismissed the credibility of a colleague’s work on the grounds that he was “running a hokey ocean.”) Clouds are another unpredictable variable: more heat will produce more clouds, which should block the sun’s rays and cool things down, say some climate modelers. But the wrong kind of clouds, say others, will trap more heat and increase the greenhouse.

Despite these uncertainties, which he discusses in detail, Schneider maintains that if nothing changes substantially, we’re looking down the barrel of the ultimate environmental crisis. As he said before a congressional committee last year: “My faith [that current global warming is caused by humanly produced carbon dioxide] is based on the principle of heat trapping by greenhouse gases and the billions of observations that support it. . . . The future is based on physics.” In other words, the details about how fast warming will occur, and exactly how it will change the weather, vary depending on which computer model you like, but the warming itself is governed by inexorable physical principles. And you can’t argue with physics.

The most sobering section is the chapter on the sources of carbon dioxide. The bad news is, unless you spend your time in the middle of a darkened room, taking shallow breaths, you’re part of the problem. Do you have fires in the fireplace on a winter evening? Do you mow your lawn with a gasoline mower? Well then, do you drive?

Conspicuously absent from both books are the tirades, beloved of Madonna et al, against the Brazilians who are destroying the rain forest. That’s a serious environmental problem, without a doubt, but Schneider and McKibben agree that our newfound concern for Amazonia is just another way of shifting the blame. If North Americans didn’t drive private cars, each of which emits its own weight in carbon dioxide every 10,000 miles, global warming wouldn’t be such an immediate threat.

If you have not slit your wrists before you get to it, Schneider’s section on how the media have handled global warming is instructive. Like many people, I’ve been secretly hoping that global warming would go the way of freeway shootings and pit-bull maulings: a brief hysterical flurry, then silence. Unfortunately, global warming is not a media construct, or not exactly. As Schneider tells it, he’s spent the past 15 years telling anyone who will listen about the consequences of carbon dioxide emissions, and getting nowhere, because the issue lacked drama and provided no arresting visuals.

Then the summer of ’88 came along. “Cracked earth, withering plants, stranded barges, and record high 100 degree temperatures flashing on outdoor bank building thermometers were commonplace visual images in the media accounts,” writes Schneider. Ironically, that summer may have been a normal, though unusual, phenomenon, unconnected to worldwide warming. Nevertheless, it got everyone’s attention on our potentially grim future.

No matter how sobering his subject, though, Schneider is a scientist, not a journalist. And whatever their flaws, scientists work on the assumption that problems have solutions. (Not that they’re always rational; one worried but ingenious correspondent to the journal Science proposed putting a mirror, 4.5 million square kilometers in size, into earth orbit, to reflect incoming solar radiation back out.)

The result of this modest optimism is that Global Warming, in the last analysis, is a sort of planetary self-help book; the last chapter offers recommendations for actions to be taken by government, industry, and individuals to cope with the crisis. (The publicity packet that came with my copy even included a checklist of things you can do to slow global warming, including the ever-popular vacuuming the refrigerator coils.) Whether or not Schneider really believes in his heart of hearts that this kind of individual action will make any difference, he professes to believe we should give it our best shot. It’s not much comfort, but it’s some.

Bill McKibben, staff writer for the New Yorker, denies us even that. His book, which was condensed in the magazine last fall, could serve as a case study in why, by and large, people don’t listen to prophets of doom. McKibben’s vision of the future is so dark that halfway through The End of Nature I stopped paying attention to what he was saying and started trying to figure out how he might be wrong and why he was trying to ruin my life.

There are various reasons for this sledgehammer impact. Like a lot of writers, McKibben is a brooder, not a doer. When he talks about himself and how he feels about the state of the planet, he’s always alone and in an attitude of contemplation: sitting at his desk, looking out the window at the dying Adirondack forest, occasionally walking in the woods. Schneider, meanwhile, zooms from coast to coast giving lectures, testifying before congressional committees, appearing on talk shows, generally acting like he’s bucking for a greenhouse merit badge. And everybody knows that taking action–any action–makes you feel better, even if it doesn’t improve anything.

The End of Nature reveals a great deal about its writer, both intentionally and unintentionally. We learn quickly that McKibben lives in a small cabin at the end of a dirt road in the Adirondacks, goes to a Methodist church because “fellowship matters,” and loves the mountains around his house with a bitter passion, because “there is no future in loving nature.” McKibben is a nature writer who feels that nature is no more, and every word of The End of Nature is permeated with that personal sense of loss.

And he isn’t just any nature writer, he’s a writer of great skill. That’s why he starts his book not with an apocalyptic vision of the greenhouse world, which most of us would be quite capable of filing away with the other dire predictions we hear daily: What’ll happen if we don’t floss? What’ll happen if we don’t get that weird noise in the car fixed? He starts with a meditation on the nature of time.

“The dinosaurs lived for nearly 140 million years,” he says. “Since even a million years is utterly unfathomable, the message is: ‘Nothing happens quickly. Change takes unimaginable–“geologic”–time.’ This idea about time is essentially mistaken.” At least it’s mistaken for those of us alive now, when “the way of life of one part of the world in one half-century is altering every inch and every hour of the globe.”

Having diminished time, he sets about diminishing space. “To any one of us the earth is enormous, ‘infinite to our senses.’ . . . But from my house to the post office at the end of the road is a trip of about six and a half miles. . . . I’ve walked it in an hour and a half. If you turned that trip on its end it would take me a mile beyond the height of Mount Everest, past the point where the air is too thin to breathe without artificial assistance. Into that tight space, and the layer of ozone above it, is crammed all that is life and all that maintains life.”

Only then, having induced claustrophobia in two dimensions, does McKibben begin to talk about the greenhouse effect. He doesn’t do it the way Schneider does, by laying out the accumulating evidence and letting it speak pretty much for itself. Nor does he write unrelieved stretches of despairing personal reflection. He does something crueler: he juxtaposes the hard science with lyrical nature writing in a way that’s guaranteed to bring you to your psychological knees. He lulls you into contemplating the pristine American landscape of a century ago as seen by explorer George Catlin, for example, then slams you with the projected decline in air quality for the LA basin over the next 30 years. And he reminds us constantly that time is short and the planet is really very small.

This might be more bearable, even constructive, if McKibben had used the conventional disaster-book format: scare us, scold us, tell us how to be saved. But he holds out almost no hope. As he sees it, global warming is an inevitable side effect of our innate need to be comfortable–to have warm houses and convenient transportation and lights at night. Even if we in the developed West were prepared to turn our backs on comfort, who would tell the people in the developing nations that they were never to have the choice? There is no enemy to fight; more accurately, the enemy is us.

The tentative political response that gives me a flicker of optimism when I read about it in the papers is utterly banal to him, as programmed and as pointless as the swarming of so many ants: “At this writing, the greenhouse effect shows every sign of becoming an important political issue. . . . There is talk of drawing up an international treaty on climate change. . . . We ought to come up with a good practical response, a series of steps, a seven-point proposal to offset the greenhouse effect. That is our reflex.” But he concludes, “The situation can only be fixed by fixing everything.” And even people with a highly developed capacity for self-delusion, like me, have a pretty good idea what the odds are against everything getting fixed.

So, as I say, midway through the book I started trying to discover why, apart from the fact that it reflects reality, The End of Nature is so unrelievedly grim. Then, on page 182, I came across the single sentence that revealed everything. McKibben is talking about the efforts he and his wife of four years are making to live in a way that doesn’t make things worse: they don’t drive much, they keep the house cold, and “we try very hard not to think about how much we’d like a baby.”

That’s the key to the difference between these two books. Schneider writes, in the acknowledgments to Global Warming, that he hopes his children will forgive him for working so hard on the issue of global warming that he was “less than a full-time father,” but he hopes the response to his book will “ease . . . their future.” McKibben doesn’t need to ask anyone to forgive him; his future ends with him.

McKibben’s book is bleak because the situation is bleak, certainly; more than that, though, it is bleak because a childless man can allow himself the luxury of despair. Stephen Schneider and those of us with children have no choice but to take possibly meaningless action, because we can’t bear for our children to suspect there may not be a future for them. And that, oddly enough, may be the best hope for the world.

Global Warming: Are We Entering the Greenhouse Century? by Stephen H. Schneider, Sierra Club Books, $18.95.

The End of Nature by Bill McKibben, Random House, $19.95.

Art accompanying story in printed newspaper (not available in this archive): illustration/Kurt Mitchell.