A new book about man’s “unappeasable appetite for energy”? With a promotional blurb from arch-Greenie Bill McKibben? It looks at first as if we are in for another Bush-bashing environmentalist diatribe telling us to turn down the thermostat, start walking, and join the Kyoto Protocol. But Alfred Crosby, emeritus professor of history, geography, and American studies at the University of Texas, has done something quite different and unexpected. He has written a direct and clearly expressed analysis of the energy problem without hysterics, apocalyptic threats, or partisan rancor.

The modest goal of “Children of the Sun” (W.W. Norton, 208 pages, $23.95) is simply to summarize the reality of our present energy “crisis” and to explain how we got here.This is a simple story, one would think, and most of us assume we already know it. But as Mr. Crosby leads us through the familiar tale – from the invention of cooking, to the Upper Paleolithic technological and cultural explosion, to the invention of agriculture and the domestication of animals – we gain a much clearer perspective of our recent evolution. Condensed and summarized in this fashion, we begin to grasp the cumulative weight and inevitability of our accelerating technological progress.

Throughout our history, energy consumption has continued to rise as new technologies found new ways to exploit what are basically different forms of energy all ultimately derived from the sun. Whether it is in the form of simple muscle power, wind, current bio-mass (wood and peat), or biomass from the past (coal and oil), we are always ready to develop new sources when the old ones give out or prove inadequate. Yet each time such an energy crisis occurs, there is desperate hand-wringing and frantic cries that the world is coming to an end because our supply of wood, whale oil, or coal is running out.

A perfect example of this occurred not long ago in the bucolic, rolling hills of Litchfield County, Conn., where today the rich are busily building their second (or is it their third?) homes.It was not always thus.At one time,not long ago, this area was the Pittsburgh of America, with iron-making blast furnaces belching black, carcinogenic smoke through the grim streets of immigrant workers’ shanties and slums.

When the local fuel supply for this industry was exhausted, wood was hauled in from as far away as Vermont. People were desperate; it seemed the American iron industry was dying.In fact,however,it had just moved to Pittsburgh, where the Bessemer converter made it possible to make steel with low-grade ore from the Great Lakes. Life continued, human ingenuity prevailed, and the Litchfield Hills sank back into a bucolic torpor to await a different kind of development.

Where Mr. Crosby’s account differs from so many other opinioned analyses is precisely at this point.”Children of the Sun” makes us understand that mankind is a part of nature,and of natural evolution. Man does not dwell outside as a separate creature, raising havoc against the “natural.” The energy history Mr. Crosby describes is the natural history of man’s expansion in the biosphere rather than the doleful tale about how we are raping this innocent virgin of a planet.

There is, of course, a Malthusian factor that cannot be ignored.The phenomenal expansion of the population was made possible by the use of ever increasing amounts of energy. Hence, we cannot solve the growing problem of our dwindling supplies of fossil fuels by turning to such popular palliatives as wind farms and solar panels, because to do so would condemn millions of our fellow humans to inevitable death. The answer to this dilemma is (as always): We must somehow find new sources of energy. The question is: where?

As “Children of the Sun” begins to address this daunting issue, we are grateful to find ourselves in the company of grown-ups.This is our crunch time, and what we need is rational and realistic discussion instead of hysteria and panic. It is true that the fossil-fuel game is winding down.There may still be a lot of oil and natural gas in the ground; the problem is that the amount of energy expended to procure it is creeping up to the amount of energy gained. What are our other options?

Hydrogen fuel cell technology looks terrific, but the problem here is the energy cost of procuring the hydrogen in the first place. “In order to provide the electricity needed to pry loose enough hydrogen to meet its full requirements, the United States would need 400 gigawatts (400 billion watts) of electricity in addition to what it already generates.”This is a virtual impossibility.”The alternative is to utilize a new and very powerful prime mover that doesn’t pollute,” Mr. Crosby tells us. “It already exists: the nuclear reactor waits at our elbow like a superb butler.”

This may be true, but many people, especially here in the United States, are fearful. After Three Mile Island and Chernobyl, the domestic nuclear power plant was practically finished. Whereas France obtains around 80% of its power from nukes,we get only 20%. “This subject,” Mr. Crosby reminds us,”which arouses fear, anger and panic, requires cool and careful analysis.”This he provides with a calm assessment of both the real dangers of nuclear plants (highly exaggerated), as well as the costs of decommissioning plants and storing wastes. It is increasingly clear that in spite of the drawbacks of fission reactors, they must now be built because no feasible alternative exists.

What about that final holy grail of power, nuclear fusion? The solution to our energy problem would be simple: We would domesticate hydrogen fusion just as we did fire long ago. No problem with radioactive waste, possible meltdowns, or need to decommission plants as with fission reactors.The potential is unlimited, but how do we do it?

Reviewing the three main techniques, our best bet seems to be a type of magnetic containment device such as the Tokamak Fusion Test Reactor at Princeton.There is now a huge version of the Princeton Tokamak under construction in France, which is expected to go on line sometime after 2014. This represents a major international effort to create a breakthrough in fusion comparable to the achievement of the famous Fermi Chicago Pile, which inaugurated the age of atomic fission.

We are at the moment of truth; poised for another quantum leap forward as we have done so many times in the past. Or, on the other hand, as Mr. Crosby wryly observes, “We may be teetering there, destined to participate in nature’s standard operating procedure of pairing a population explosion with a population crash.” Stay tuned.