Bill McKibben is the founder of the global climate movement 350.org and the author of the novel "Radio Free Vermont."



The shoreline in Miami, a low-lying city threatened by rising sea levels. (Joseph Michael Lopez/For The Washington Post)

Some of humanity's most primordial stories involve flooding: The tales of Noah, and before that Gilgamesh, tell what happens when the water starts to rise and doesn't stop. But for the 10,000 years of human civilization, we've been blessed with a relatively stable climate, and hence flooding has been an exceptional terror. As that blessing comes to an end with our reckless heating of the planet, the exceptional is becoming all too normal, as residents of Houston and South Florida and Puerto Rico found out already this fall.

Hurricanes Harvey, Irma and Maria provide a dramatic backdrop for the story Jeff Goodell tells in "The Water Will Come": If there was ever a moment when Americans might focus on drainage, this is it. But this fine volume (which expands on his reporting in Rolling Stone) concentrates on the slower and more relentless toll that water will take on our cities and our psyches in the years to come. Those who pay attention to global warming have long considered that its effects on hydrology — the way water moves around the planet — may be even more dramatic than the straightforward increases in temperature.

To review the basic physics: Warm air holds more water vapor than cold air does, which means you get more evaporation and hence drought in arid areas, and more rainfall and hence floods in wet ones. (Harvey, for example, was the greatest rainfall event in American history, the kind of deluge possible only in a warmer world.) Meanwhile, heat melts ice: Greenland and the Antarctic are vast stores of what would otherwise be ocean, and now they're beginning to surrender that water back to the sea.

These effects were somewhat harder to calculate than other impacts of climate change. In particular, scientists were slow to understand how aggressively the poles would melt, and hence the main international assessments, until recently, forecast relatively modest rises in sea level: three feet, perhaps, by century's end. That's enough to cause major problems, but perhaps not insuperable ones — richer cities could probably build seawalls and other barriers to keep themselves above the surface. Yet new assessments of the disintegration of glaciers, and more data from deep in the Earth's past, have convinced many scientists that we could be looking at double or triple that rate of sea level rise in the course of the century. Which may take what would have been a major problem and turn it into a largely insoluble new reality.

Consider Miami and Miami Beach, where Goodell has concentrated much of his reporting. Built on porous limestone or simply mounds of mud dredged from the surrounding sea, low-lying South Florida streets already flood regularly at especially high tides. The simple facts, however, haven't stopped the Miami real estate boom: When Irma hit, more than 20 huge cranes were at work building high-rises (and two of them toppled). Goodell manages to track down the city's biggest real estate developer, Jorge Perez, at a museum opening. He was not, he said, worried about the rising sea because "I believe that in twenty or thirty years, someone is going to find a solution for this. If it is a problem for Miami, it will also be a problem for New York and Boston — so where are people going to go?" (He added, with shameless narcissism, "Besides, by that time I'll be dead, so what does it matter?")

Goodell dutifully tracks down the people who are working on those "solutions" — the Miami Beach engineers who are raising city streets and buildings; their Venetian counterparts who are building a multibillion-dollar series of inflatable booms that can hold back storm tides. In every case, the engineering is dubious, not to mention hideously expensive. And more to the point, it's all designed for the relatively mild two- or three-foot rises in sea level that used to constitute the worst-case scenarios. Such tech is essentially useless against the higher totals we now think are coming, a fact that boggles most of the relevant minds. When a University of Miami geologist explains to some Florida real estate agents that he thinks sea level rise may top 15 feet by 2100, Goodell describes one "expensively dressed broker who was seated near me" who sounded "like a six-year-old on the verge of a temper tantrum. . . . 'This can't be a fear-fest,' she protested. 'Why is everyone picking on Miami?' "



Wealthier coastal cities, such as Miami, may be able to engineer solutions to hold back rising seas. Poorer places will have fewer options. (Joseph Michael Lopez/For The Washington Post)

No one is picking on Miami. But the developed world is definitely picking on the low-lying islands of the Pacific and Indian oceans. (Goodell gives sharp descriptions of the imperiled Marshalls and the outsize role the nation played in international climate negotiations.) The vast majority of people at risk live in places such as Bangladesh and Burma, where rising seas are already swamping farmland and forcing internal migration, mostly of people who have burned so little fossil fuel that they have played no serious part in causing the crisis we now face.

There are precisely two answers that give some hope to a world facing this greatest of all challenges. The first is to stop burning fossil fuels. If we moved with great speed toward 100 percent renewable energy, we might still hold sea level rise to a meter or two. And this is now a realistic possibility: The rapid fall in the price of wind and solar power over the past few years means we could conceivably make the transition in time. That's precisely what President Trump is now preventing (and to be fair, it's more than President Barack Obama wanted to do, either — Goodell's extensive interviews with the former president capture both his fine rhetoric and his sad policy waffling). At this point, the world seems more likely to stumble along a path of slow conversion to clean energy, guaranteeing that the great ice sheets will crumble.

The other way forward is to adapt to the unpreventable rise in sea level. Goodell describes a few of the plans for floating buildings and such, but if you want a real sense of what this option looks like, you're better off reading Kim Stanley Robinson's massive and massively enjoyable novel "New York 2140," published this year. Robinson is described as a science fiction writer, but in this case he's more like a political scientist, describing a New York a century from now that's been largely inundated but where people inhabit (often with surprising good cheer) the ever-shifting intertidal zone. Of course, this metro-size version of the Swiss Family Robinson happens only after two great pulses of sea level rise have killed off a huge percentage of the human population, so it's not the ideal scenario.

Or we could take the path laid out by Miami Beach Mayor Philip Levine at the 100th anniversary of the founding of Miami Beach. "If, thirty or forty years ago, I'd told you you were going to be able to communicate with your friends around the world with a phone you carried around in your pocket," he said in 2015, "you would think I was out of my mind." Thirty or 40 years from now, he promised, "we're going to have innovative solutions to fight back against sea-level rise that we cannot even imagine today." Forget building the ark, Noah — we've got an app for that.