Buried in Muck, Clues to Future NYC Drought

Climatologist Dorothy Peteet is combing through New York-area marshes for clues to future drought.Tim McDonnell/Climate Desk


Piermont Marsh seems an unlikely place to learn about drought. This warren of narrow streams and muddy, reed-choked embankments clinging to the edge of the Hudson River twenty miles north of Times Square is the domain of crabs, worms, herons, and other water-loving creatures. But as Columbia University climatologist Dorothy Peteet paddles a narrow aluminum canoe deep into the marsh, she insists that buried deep in this black, sulphur-stinking muck are clues that could reveal when, and how badly, the nation’s largest city will next be struck by crippling drought.

Here, she says, “we can get these climate records that we can’t get anywhere else.”

Some climate researchers tap ancient air bubbles trapped in Arctic ice to read long-lost atmospheres; some slice open stalagmites in tropical caves to measure 100,000-year-old rainfall. Peteet is on the hunt for pollen. She dredges up mud from as deep as 45 feet underground and hauls it back to her lab at the nearby Lamont-Doherty Earth Observatory. There she boils, bakes, and filters it to sift out pollen, not much thicker than a human hair, from plants several thousand years old. The relative abundance and variety of different species indicate climate conditions at the time the pollen was dropped: An uptick of dry-weather species like hickory and pine points to drought.

Dorothy with sample

Pollen, and seeds like these, could shed light on how future droughts will impact New York City. Tim McDonnell/Climate Desk

Pollen, she says, “is a secure piece of the puzzle;” changes in the pollen record from the deepest, oldest mud layers to shallow, more recent ones paint a clear picture of climate-driven changes over time. And some of these changes are startling: In 2005, Peteet unearthed evidence of a 500-year-long drought that baked the New York City region from 800 to 1300 A.D., a time known as the Medieval Warming Period (because this ancient warming happened in an age before human greenhouse gas emissions, it’s become a favorite reference of climate skeptics; however, today’s temperatures are even warmer than then, and recent science indicates that the Medieval warming was driven by higher-than-normal solar radiation and lower-than-normal volcanic activity. It was also concentrated in the Northern Hemisphere, unlike contemporary global warming, which is worldwide). Now, she wants to dig deeper and in more marshes to better understand how frequently such droughts happen.

The pursuit isn’t purely academic: In 1961 the Northeast was hit by what would become that region’s longest and most severe drought on record. By 1963, the New York City water supply had dropped over seventy percent, leaving the city’s desperate water manager to beg restaurants not to serve water unless patrons asked for it, and for taxi drivers not to wash their cars more than twice a week.

“What is it going to be like if we have a 500 year drought?” Peteet says. Piecing together the pollen record, she says, can help establish patterns that policymakers and the public could draw on to better anticipate what the future will hold. As it stands, climate scientists think New York is in for hotter and wetter conditions, which, meteorologist Kevin Trenberth of the National Center for Atmospheric Research explains, can, somewhat counterintuitively, lead to more droughts. Precipitation is expected to increase, but it will happen in a series of severe downpours interspersed with dry spells; warmer temperatures in these dry spells can prolong them and increase the risk of drought.

“So all you have to do is miss some of these storms, and they’re very hit or miss, and you can end up with drought conditions even if the seasonal precipitation doesn’t look abnormal,” Trenberth says.

Since man-made climate change is happening on top of natural patterns, Peteet says, establishing a baseline through historic climate records like pollen can shed light on how a particular region will respond to predicted changes. For New York, she says, there’s no better place to look than in marshes…even when it means trudging through waist-deep mud. Her goal now is to find financing for a project to dig pollen samples from deeper reaches of more of the area’s marshes.

“I love coring a new spot,” she says, “because you never know what you’ll find.”

More Mother Jones reporting on Climate Desk

AN IMPORTANT UPDATE

We’re falling behind our online fundraising goals and we can’t sustain coming up short on donations month after month. Perhaps you’ve heard? It is impossibly hard in the news business right now, with layoffs intensifying and fancy new startups and funding going kaput.

The crisis facing journalism and democracy isn’t going away anytime soon. And neither is Mother Jones, our readers, or our unique way of doing in-depth reporting that exists to bring about change.

Which is exactly why, despite the challenges we face, we just took a big gulp and joined forces with The Center for Investigative Reporting, a team of ace journalists who create the amazing podcast and public radio show Reveal.

If you can part with even just a few bucks, please help us pick up the pace of donations. We simply can’t afford to keep falling behind on our fundraising targets month after month.

Editor-in-Chief Clara Jeffery said it well to our team recently, and that team 100 percent includes readers like you who make it all possible: “This is a year to prove that we can pull off this merger, grow our audiences and impact, attract more funding and keep growing. More broadly, it’s a year when the very future of both journalism and democracy is on the line. We have to go for every important story, every reader/listener/viewer, and leave it all on the field. I’m very proud of all the hard work that’s gotten us to this moment, and confident that we can meet it.”

Let’s do this. If you can right now, please support Mother Jones and investigative journalism with an urgently needed donation today.

payment methods

AN IMPORTANT UPDATE

We’re falling behind our online fundraising goals and we can’t sustain coming up short on donations month after month. Perhaps you’ve heard? It is impossibly hard in the news business right now, with layoffs intensifying and fancy new startups and funding going kaput.

The crisis facing journalism and democracy isn’t going away anytime soon. And neither is Mother Jones, our readers, or our unique way of doing in-depth reporting that exists to bring about change.

Which is exactly why, despite the challenges we face, we just took a big gulp and joined forces with The Center for Investigative Reporting, a team of ace journalists who create the amazing podcast and public radio show Reveal.

If you can part with even just a few bucks, please help us pick up the pace of donations. We simply can’t afford to keep falling behind on our fundraising targets month after month.

Editor-in-Chief Clara Jeffery said it well to our team recently, and that team 100 percent includes readers like you who make it all possible: “This is a year to prove that we can pull off this merger, grow our audiences and impact, attract more funding and keep growing. More broadly, it’s a year when the very future of both journalism and democracy is on the line. We have to go for every important story, every reader/listener/viewer, and leave it all on the field. I’m very proud of all the hard work that’s gotten us to this moment, and confident that we can meet it.”

Let’s do this. If you can right now, please support Mother Jones and investigative journalism with an urgently needed donation today.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate