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Ancient Vikings as environmentally adept, and other nonelection reads

I’ve gone disk full on election material for a while — and if you have, too, there may be respite in these writings.

I wish I had something new and useful to offer, truly I do, about our elevation to the American presidency of a man whose campaign sloganeering surely qualifies him as an anti-environmental terrorist. But alas.

Over the weekend I went disk full on all the post-election awfulizing and gave up looking for fresh insights into how Donald Trump might actually lead, and how much progress he can realistically undo. Instead I turned to some of the longer recent nonpolitical reads I’d laid aside for later, and on the thought that some of you might be in the same canoe, I offer excerpts/links for four of the most compelling. No paywalls.

First up is Eli Kintisch’s “The Lost Norse: Why Did Greenland’s Vikings Disappear?” It ran last week in the journal Science and explores new challenges to the commonplace notion that these settlers were wiped out by careless use of resources in a changing climate.

Many will recognize that narrative as a key example in Jared Diamond’s popular (and worthy) “Guns, Germs and Steel”: that Norse agriculture and timbering practices damaged the productivity of their farmland, while disdain for the indigenous Inuit reliance on fish and seal meat, in favor of introduced beef and lamb, robbed them of an essential protein source.

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Over the last decade, however, new excavations across the North Atlantic have forced archaeologists to revise some of these long-held views. …

The findings suggest that the Greenland Norse focused less on livestock and more on trade, especially in walrus ivory, and that for food they relied more on the sea than on their pastures. There’s no doubt that climate stressed the colony, but the emerging narrative is not of an agricultural society short on food, but a hunting society short on labor and susceptible to catastrophes at sea and social unrest.

Among Kintisch’s sources is Thomas McGovern, an archaeologist from Hunter College who turns out to be an important author of both the old and the new versions of Viking collapse. In the 1970s and 1980s, his work supported the idea that they were “doomed by fatal Norse conservatism in the face of fluctuating resources.”

Three decades later here at Tasilikulooq (TA-SEE-LEAK-U-LOCK), a modern Inuit farm of green pastures flanked by lakes, a couple of McGovern’s students and others are busy exploring the remains of a medium-sized farm that once housed sheep, goats, horses, and a few cows. Two graduate students in rubber overalls hose 700-year-old soil off unidentified excavated objects near a midden downhill from a collapsed house. A brown button the size of a nickel emerges on the metal sieve.

The button was carved from a walrus tooth, and becomes a symbol of endeavor that joined a plentiful resource to newly appreciated artisanship and an early exercise in international (or at least intercultural) trade.

The high value that medieval Europe placed on walrus ivory would have provided plenty of incentive to pursue it in Greenland. Craftsmen used ivory in luxury ornaments and apparel, and in objects like the famous Lewis chess set, discovered in Scotland in 1831. In 1327, an 802-kilogram parcel of Greenland tusks was worth a small fortune—the equivalent of roughly 780 cows or 60 tons of dried fish, according to tithing records analyzed in 2010 by University of Oslo archaeologist Christian Keller. …

Nor were the Norse incompetent farmers, as Diamond and others have suggested. Soil geographer Ian Simpson of the University of Stirling in the United Kingdom says previous studies overestimated the Norse contribution to erosion in Greenland. New pollen and soil data show that the Norse allowed fields and what little forest existed to recover after tilling and turf cutting. And in analyses of soil and lake sediment cores, researchers have found chemical and paleoecological clues indicating that Norse farmers skillfully maintained pastures with manure fertilizer and irrigation ditches.

Such findings, along with the ivory evidence, have transformed ideas about Norse society, says McGovern, whose beard is now white. “You start to see old data, like the seal bones in the middens, in a new light. It’s exciting to get a chance to revise your old thinking before a younger colleague can,” he says. “We used to think of Norse as farmers who hunted. Now, we consider them hunters who farmed.”

But a rapidly cooling climate overcame their abilities to adjust by adding more fertilizer and watering more often; by the year 1400 or so, Europe began to import ivory from the African elephant and Russian walrus. Greenland’s Norse began their slide toward oblivion, overcome by the forces of a changing climate and globalized trade.

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The failings of GMO crops

From Danny Hakim at the New York Times, an investigation of “Doubts About the Promised Bounty of Genetically Modified Crops,” which focuses not on arguments over health risks or gene drift but perhaps the most fundamental question of all: Do they deliver?

His conclusion: “Genetic modification in the United States and Canada has not accelerated increases in crop yields or led to an overall reduction in the use of chemical pesticides.”

The promise of genetic modification was twofold: By making crops immune to the effects of weedkillers and inherently resistant to many pests, they would grow so robustly that they would become indispensable to feeding the world’s growing population, while also requiring fewer applications of sprayed pesticides.

Twenty years ago, Europe largely rejected genetic modification at the same time the United States and Canada were embracing it. Comparing results on the two continents, using independent data as well as academic and industry research, shows how the technology has fallen short of the promise.

An analysis by The Times using United Nations data showed that the United States and Canada have gained no discernible advantage in yields — food per acre — when measured against Western Europe, a region with comparably modernized agricultural producers like France and Germany. Also, a recent National Academy of Sciences report found that “there was little evidence” that the introduction of genetically modified crops in the United States had led to yield gains beyond those seen in conventional crops.

At the same time, herbicide use has increased in the United States, even as major crops like corn, soybeans and cotton have been converted to modified varieties. And the United States has fallen behind Europe’s biggest producer, France, in reducing the overall use of pesticides, which includes both herbicides and insecticides.

In search of the great gray owl

From Audubon magazine’s fall issue, I might suggest Nancy Bazilchuk’s piece on how “After 100 Years, Scientists Are Finally Starting to Understand the Mysterious Great Gray Owl.”

Obviously a majestic bird, with its 5-foot wingspread and silent flight, this owl is threatened by a range of pressures from West Nile virus to habitat loss and, unfortunately, automobile impacts.

This adds importance to better understanding the size and locations of its populations, but the owls are especially well camouflaged, easily spooked and inclined to live a long way from the trail. The task is becoming easier with remote listening equipment developed by bird-tracking detectives like Joe Medley.

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With his tousled dirty blonde hair, and a wardrobe that skews heavily toward Carhartt jeans, Joe Medley, 33, has that mildly rumpled look of someone who has spent thousands of hours sitting in the woods, listening for rare birds.

One early evening this past spring, Medley, then a graduate student at the University of California, Davis, homed in on a charred ponderosa pine spattered with what looked like white paint. It sat at the edge of a mid-elevation wet meadow in the 900,000-acre Stanislaus National Forest on the western side of Yosemite National Park. He knew the whitewash, combined with a few scattered oval pellets the size of cigar stubs, was strong evidence that a Great Gray Owl had perched there, listening for prey out in the meadow. Thus he got to work, hooking up two black teacup-size funnels to one of the pine’s broken branches. Each funnel held a sensitive microphone wired to a recorder in a waterproof case, capable of logging the sounds of the meadow for a week or more.

Sensitive and long-listening, yes, but the microphones hear everything, and so it was necessary to develop a kind of voice-recognition software that could filter out other birdcalls and animal sounds, then enable tagging of individual great grays.

At first, the software tagged everything that remotely sounded like an owl: Coyotes yipping. The rumble of a high-elevation jet. Bears crunching on the microphones. The constant beeping of a Red-breasted Nuthatch, like a truck stuck in reverse.

The worst were the incessant alarm calls of Douglas’ squirrels. No matter how much Medley tweaked the software, the squirrel calls “skipped right through,” because they were so similar to juvenile owl calls. It was a major problem. If he couldn’t find a way to deal with all the false positives, he wouldn’t be able to use the software to detect young birds, a key indicator of the population’s health.

By the following winter, Medley had used a statistical tool called a random forest analysis to finally crack the false-positive problem and make his surveillance technique work at a practical level. As he culled the data, insights began to emerge. For one thing, Great Gray Owls were positively noisy when people weren’t around. In the end, he identified 7,445 male, 13,163 female, and 43,004 juvenile calls, and showed that acoustic monitoring was as effective as traditional survey techniques, with the advantage that it doesn’t bother the birds.

Greenland is melting — and fast

And though I’ve already included a Greenland piece in this roundup for your reading list, and not for the first time, I have to speak up for yet another gem from The New Yorker’s Elizabeth Kolbert, who gets up close and personal with its rapidly shrinking ice sheet in “Greenland Is Melting.”

Visiting a team of researchers studying a flow of meltwater called the Rio Behar, Kolbert camps on a portion of the sheet dotted with perfectly round puddles, and too soft to hold tent stakes. They are investigating a moulin, a vertical ice stream dropping away from the surface.

A line of yellow caution tape had been strung about fifty yards from the Behar’s edge. Anyone venturing beyond that line, I was instructed, had to be tethered. I borrowed a mountaineering harness, clipped in, and made my way to the bank, where the team’s leader, Larry Smith, was conferring with a pair of graduate students. By ice-sheet standards, it was a balmy day—around thirty-two degrees—and Smith was wearing canvas work pants; two plaid shirts, one on top of the other; and a red fleece cap that said “Air Greenland.”

“Do you hear that?” he asked me. Above the rush of the river, there was a roaring sound, like waves crashing against a distant cliff. “That’s the moulin.”

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Is anyone more adept than Kolbert at making nature’s complex phenomena intelligible to the utterly unacquainted? I think not. Here’s what she says about the state of an ice sheet whose lowest layer formed from snow that fell before the beginning of the last ice age, 15,000 years ago.

The ice sheet is so big—at its center, it’s two miles high—that it creates its own weather. Its mass is so great that it deforms the earth, pushing the bedrock several thousand feet into the mantle. Its gravitational tug affects the distribution of the oceans.

In recent years, as global temperatures have risen, the ice sheet has awoken from its postglacial slumber. Melt streams like the Rio Behar have always formed on the ice; they now appear at higher and higher elevations, earlier and earlier in the spring. This year’s melt season began so freakishly early, in April, that when the data started to come in, many scientists couldn’t believe it. “I had to go check my instruments,” one told me. In 2012, melt was recorded at the very top of the ice sheet. The pace of change has surprised even the modellers. Just in the past four years, more than a trillion tons of ice have been lost. This is four hundred million Olympic swimming pools’ worth of water, or enough to fill a single pool the size of New York State to a depth of twenty-three feet.

An ice cube left on a picnic table will melt in an orderly, predictable fashion. With a glacier the size of Greenland’s, the process is a good deal more complicated. There are all sorts of feedback loops, and these loops may, in turn, spin off loops and sub-loops. For instance, when water accumulates on the surface of an ice sheet, the reflectivity changes. More sunlight gets absorbed, which results in more melt, which leads to still more absorption, in a cycle that builds on itself. Marco Tedesco, a research professor at Columbia’s Lamont-Doherty Earth Observatory, calls this “melting cannibalism.”

As moulins form at higher elevations, more water is carried from the surface of the ice to the bedrock beneath. This lubricates the base, which, in turn, speeds the movement of ice toward the ocean. At a certain point, these feedback loops become self-sustaining. It is possible that that point has already been reached.