We Ruined Rain

Water gave every living thing on Earth the gift of existence. And yet, of late, it seems determined to wipe us out. The Atlantic hurricane season, widely predicted to be a fierce one, is here, and early this morning the first named storm, Alberto, made landfall in northeastern Mexico and drenched everything in its path.

And in Florida last week, it was as if the heavens had turned on the tap and simply left it running. The state’s south usually gets about eight to 10 inches of rain throughout June; some parts of Southern Florida received about 20 inches of rain in just 24 hours, turning streets impassable, damaging homes, and enveloping cars.

This type of rainfall has become more frequent and intense in recent decades. A warmer atmosphere can hold more moisture, and plenty is available as warmer temperatures at the Earth’s surface allow more water to evaporate. In a hotter world, when it rains, it really pours. Experts call torrents such as those in Florida 100-year storms, even 1,000-year storms. And yet, they’ve been occurring with alarming frequency across the United States and in other parts of the world.

Extreme precipitation is a sign of how fundamentally humans have managed to alter the workings of our planet. The first rains on Earth fell several billion years ago, covering the once-molten surface with seas where life eventually emerged. Even now, as scientists search for signs of habitable worlds beyond Earth, they follow the water because they understand that it turned this little ball of rock into a paradise for life. But by burning fossil fuels for about 250 years—no time at all, on the scale of our planet’s history—humans have turned a cosmic wonder into a weapon.

[Read: Playing God with the atmosphere]

Climate change has disrupted the water cycle, speeding up every phase in the ancient, endless process that circulates H2O among the oceans, atmosphere, and land. Global sea levels have risen about 0.15 inches each year over the past decade, more than double the annual increase recorded in the 20th century, both because the ice at Earth’s poles is melting (even faster than predicted) and because water expands when it warms. The excess threatens to inundate coastal communities, especially during rainstorms, and eat away at their shores; one inch of sea-level rise leads to the loss of 8.5 feet of coastline.

Meanwhile, hurricanes, fueled by hot oceans, are becoming wetter. Even non-hurricane storms, combined with rising seas, are turning dangerous and straining infrastructure. The storm in Florida overwhelmed Miami’s already struggling canal network, where “less rain, or rain that fell at a gentler rate, would have drained away easily,” Mario Alejandro Ariza wrote in The Atlantic earlier this week.

The heavy rain in Mexico is, in some ways, a blessing—the area has recently been parched. Droughts are growing in severity around the world, but even when they’re broken by rainstorms, the relief comes with its own dangers. Over the past couple of winters, record-breaking rains have rescued California from a prolonged drought, but they have also produced deadly floods.

If you zoom out over the storm clouds to consider Earth as it truly is—a planet orbiting one of countless stars, a tiny blue dot in an endless universe—the way we’re treating our precious water starts to look like a cosmic disgrace. Astronomical observations have turned up evidence of rain on other worlds, but the droplets are made of methane, iron, quartz, and even sand, not the H2O that helped create and nourish life as we know it.

[Read: We’re gambling with the only good oceans in the universe]

When astronomers look for the signature of water farther afield, in the atmospheres of planets around other suns, they’re imagining the possibility not just of microbial life—the types of aliens that we’re looking for in our own solar system—but of intelligent beings, members of an advanced civilization that has amassed stories and records of its own water cycle. After all, “rain is not only part of our chaotic atmosphere, but part of our chaotic selves—connected in every holy book from the Bible to the Rig Veda, every human genre from cuneiform script to Chopin,” the journalist Cynthia Barnett wrote in Rain: A Natural and Cultural History in 2015. If water gave rise to all that here, why couldn’t the same be true on another planet?

The thought of such a discovery is what makes the detection of water vapor on some far-off exoplanet so exciting, especially when that world orbits within its star’s habitable zone, as Earth does. But the presence of some water isn’t itself a guarantee of life. The sheer amount of water on our planet is, as far as astronomers can tell, a remarkably lucky exception. The other rocky planets in our neighborhood, Venus and Mars, had their own water cycles, with oceans and rain, before they boiled and froze, respectively. But Earth has managed to hold on to its water, the gift that started it all.

For Michael Rawlins, a professor at the University of Massachusetts at Amherst who studies the water cycle, the increase in historic deluges feel almost karmic. “Societies around the globe have developed because of the use of fossil fuels,” Rawlins told me; tapping that ancient reservoir became its own problem as the resulting carbon emissions warmed the planet. Water, even more crucially, made life here possible, and yet now, because of climate change, that too “is almost coming back to bite us.” But fossil fuels were not a precondition to our existence. Water is, and we’re acting as if maintaining its balance is not a paramount condition of our future. In the past, we attributed such devastating rains and floods to divine powers, the work of unseen, raging gods. But in this age, we have to face the reality that we’re the ones who have turned a cosmic abundance into a cataclysm.