…as William deBuys demonstrates in his wonderful new book, A Great Aridness.

DeBuys, an accomplished New Mexico writer and conservationist, understands that a lack of water is what gives this iconic landscape its impossibly blue skies and unique wildlife.

But life in these arid lands is a precarious affair. Death or even extinction is never more than an extended drought away. As deBuys observes, “the North American Southwest promises to be center stage for the continent’s drama of climate change.” The beauty of deBuys’s approach is that by focusing on one region, sorting out the effects of global climate change becomes at once more manageable and more personal.

A Great Aridness: Climate Change and the Future of the American Southwest began life as an environmental history of the Southwest. Happily, the book’s origins are etched into nearly every page. As deBuys — accompanied by a colorful cast of experts — tracks climate change across the Colorado Plateau, up Arizona’s highest “sky island,” and into the lush grasslands of Mexico’s Río Gavilán, he skillfully weaves together current scientific research with compelling tales of the past.

In what could be the pilot for a show called CSI: Paleo-Southwest, deBuys ponders the likely fate of a 45-year-old male whose skeletal remains suggest that he was murdered by a crushing blow to the head around the year 1300 in arid southwestern Colorado. Dozens of other residents of Sand Canyon Pueblo were massacred at the same time — all of them women, children, or elderly people — and the site was abandoned.

Life had been difficult for some time before the slaughter. Used to a diet rich in corn and meat, the people of Sand Canyon had been subsisting on wild plants and the occasional rabbit. Tree rings indicate that the area was suffering through a multi-decade megadrought. The men who would have otherwise defended the pueblo were probably far away hunting game that had migrated in search of water. Sand Canyon was likely overrun by another group, who were themselves set in motion by the drought, killing for whatever scarce resources remained, before moving on in search of water.

Sand Canyon is a sharp rebuke for those who seek comfort in the fact that climate change is part of a natural cycle. We’ve survived droughts before — but the suffering has been enormous. Worse yet is the prospect that human activity may turn a prolonged dry spell into something far worse. As deBuys warns: “There’s a possibility that the next megadrought has already begun — we just don’t know it yet.” Our fate outruns our understanding.

DeBuys does an excellent job presenting information to back up his claims in a way that is never burdensome. In the previous decade, he explains, the Colorado River — the lifeline for much of the Southwest— shrank to its lowest flow on record. Average nighttime temperatures in Phoenix climbed as the desert was converted to heat-absorbing pavement. The number of major forest fires has quadrupled over the past three decades, and the biggest fires have grown six times larger in that span of time.

A swelling Sunbelt population demands more water, even as climate change is reducing the available supply. How we deal with these two conflicting realities will determine the future of the American Southwest.

In the end, writes deBuys, we must “live within the limits of finite resources” — something we should have been doing all along. “In an environment where climate speaks last and loudest, the ultimate train wreck, the final reckoning with aridity, becomes a certainty.”

Compelling, thoughtful, and frequently lyrical, A Great Aridness is the best book on climate change since Bill McKibben’s classic The End of Nature.

Osha Gray Davidson, author of five books of nonfiction, publishes The Phoenix Sun, a syndicated online news and analysis site covering solar power from the American Southwest.