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Some of the water flooding N.H. beaches is coming from Greenland, and it’s not going to stop

  • A photo from "Camp Dartmouth" on the Greenland ice in 2016, from a blog maintained by Erich Osterberg, at greentracs.blogspot.com. Dartmouth College—Courtesy



Monitor staff
Monday, December 12, 2016

If you’ve been in Hampton or Seabrook during a “king tide” recently, splashing through seawater covering roads and sidewalks, you might wonder where all that water came from.

Some of it might have come from underneath Erich Osterberg’s feet.

Osterberg, an assistant professor in the department of earth science at Dartmouth College, has been traveling to the country of Greenland for five years doing research about the island’s enormous glaciers and working with a team drilling ice cores and gathering data about the glaciers’ history.

So Osterberg has stood near an awful lot of melting ice during these years of record warmth. How warm?

“This past spring, with our expedition, it was April but it was 70 degrees on the coast of Greenland,” Osterberg said. We were talking on the phone, but I’m pretty sure I heard him shaking his head in dismay.

That warming also leads to the sort of stories you’d expect from an Arctic researcher.

“Traditionally, there were no polar bears on the land in summer – they’re out on the sea ice. But (summer of 2012) there was no ice in the bay for the first time in memory. There were polar bears going through the military base,” he said. “We had to scramble to try to find rifles. For the first time, we were going to have to worry about polar bears in camp.”

Melting has always been part of the annual cycle for these massive glaciers – and I mean massive, since there are roughly 680,000 cubic miles worth of ice on Greenland. But as research by Osterberg’s team and a number of other scientists has shown, recent years have seen melting accelerate. “Even being there as infrequently as we are – a couple months a year – we can see these changes happening,” Osterberg said.

Osterberg focuses on surface melting on the western side of the island.

“This is a very sensitive area of ice sheet. You get some melting every summer, but the question is how much? We drill these ice cores that look back 30, 40, 50 years in time, see that clearly in ice cores there are more layers of melting. Thicker and more melt layers,” he said. “It’s clear as day, showing how warming has increased the melting on the western part of the ice sheet.”

Sea ice is also melting, both in the Arctic and around Antarctica this year. That is particularly alarming, since usually the poles alternate their temperature swings. This is the first year in which sea ice has shrunk at both poles.

But when sea ice melts, it doesn’t affect New Hampshire beaches because it doesn’t raise the level of the ocean, any more than melting ice makes your drink overflow. It’s another matter when ice on land melts, like it is in Greenland. That adds water to the ocean, contributing to sea-level rise that has already begun because warming ocean water expands in volume.

Over the next few decades, this problem will become increasingly serious but for the moment, it’s most visible during “king tides” – when seawater rises into places where it’s not usually seen, even without storms pushing it. It has become common enough that NOAA now issues high tide bulletins and is warning that king tides could be coming later this week.

Florida is ground zero for the king tide problem and due to our geography, New Hampshire is less vulnerable that many other parts on the eastern seaboard. But it still happens here and will almost certainly get worse.

If you’re dubious, check out the New Hampshire Coastal Adaptation Workgroup, a public/private collection of folks trying to cope with this slow-moving disaster. It holds an annual “king tide” photo contest to demonstrate the phenomenon.

Osterberg, who spends time at what could be called the headwaters of this flooding, knows it is only going to worsen.

“2015 didn’t just break the (global temperature) record by a fraction of a degree Celcius – we shattered it,” he said. “And 2016 is going to destroy last year’s record.”

He added, “People become complacent, you hear it so often: This is the warmest year on record. ... But it’s serious.

Before the beaches and tide marshes disappear under the ocean waves, however, let’s end this column on a more upbeat note.

“When I teach this to the students they get it – they’ve been hearing it their whole lives. (Global warming) is not questioned for the most part; they understand that humans are largely responsible for it,” he said. “I am optimistic that as they continue to assume positions of power in our society and our politics, these debates that we’re still having will end. ... Long-term, I’m quite optimistic that we’re going to tackle this problem.”

A final note: Dartmouth has put together a nice video of Greenland science from Osterberg and others. Search YouTube for “Finding Out How Fast Greenland Is Melting.”

(David Brooks can be reached at 369-3313 or dbrooks@cmonitor.com or on Twitter @GraniteGeek.)