Category Archives: Climate Change

Canadian oil production, Climate Change, ExxonMobil, Global warming, Oil exports, Oil imports, Oil Industry, Oil prices, Paris Climate Agreement

Flood of Oil Is Coming, Complicating Efforts to Fight Global Warming

A surge of oil production is coming, whether the world needs it or not.

A Norwegian oil platform in the North Sea. Norway’s production has declined for two decades, but its development of the Johan Sverdrup deepwater field should reverse the trend.
A Norwegian oil platform in the North Sea. Norway’s production has declined for two decades, but its development of the Johan Sverdrup deepwater field should reverse the trend. Credit…Nerijus Adomaitis/Reuters
The New York Times, by Clifford Krauss, Nov. 3, 2019

HOUSTON — The flood of crude will arrive even as concerns about climate change are growing and worldwide oil demand is slowing. And it is not coming from the usual producers, but from Brazil, Canada, Norway and Guyana — countries that are either not known for oil or whose production has been lackluster in recent years.

This looming new supply may be a key reason Saudi Arabia’s giant oil producer, Aramco, pushed ahead on Sunday with plans for what could be the world’s largest initial stock offering ever.

Together, the four countries stand to add nearly a million barrels a day to the market in 2020 and nearly a million more in 2021, on top of the current world crude output of 80 million barrels a day. That boost in production, along with global efforts to lower emissions, will almost certainly push oil prices down.

Lower prices could prove damaging for Aramco and many other oil companies, reducing profits and limiting new exploration and drilling, while also reshaping the politics of the nations that rely on oil income.

The new rise in production is likely to bring economic relief to consumers at the gas pump and to importing nations like China, India and Japan. But cheaper oil may complicate efforts to combat global warming and wean consumers and industries off their dependence on fossil fuels, because lower gasoline prices could, for example, slow the adoption of electric vehicles.

Canada, Norway, Brazil and Guyana are all relatively stable at a time of turbulence for traditional producers like Venezuela and Libya and tensions between Saudi Arabia and Iran. Their oil riches should undercut efforts by the Organization of the Petroleum Exporting Countries and Russia to support prices with cuts in production and give American and other Western policymakers an added cushion in case there are renewed attacks on oil tankers or processing facilities in the Persian Gulf.

Driving New Production

Daniel Yergin, the energy historian who wrote “The Prize: The Epic Quest for Oil, Power and Money,” compared the impact of the new production to the advent of the shale oil boom in Texas and North Dakota a decade ago.

“Since all four of these countries are largely insulated from traditional geopolitical turmoil, they will add to global energy security,” Mr. Yergin said. But he also predicted that as with shale, the incremental supply gain, combined with a sluggish world economy, could drive prices lower.

There is already a glut on the world market, even with exports from Venezuela and Iran sharply curtailed by American sanctions. Should their production come back, that glut would only expand.

Years of moderate gasoline prices have already increased the popularity of bigger cars and sports utility vehicles in the United States, and the probability of more oil on the market is bound to weigh on prices at the pump over the next few years.

The oil-supply outlook is a sharp departure from the early 2000s, when prices soared as producers strained to keep up with ballooning demand in China and some analysts warned that the world was running out of oil.

Then came the rise of hydraulic fracturing and drilling through tight shale fields, which converted the United States from a needy importer into a powerful exporter. The increase in American production, along with a choppy global economy, shaved oil prices from well over $100 a barrel before the 2007-9 recession to about $56 on Friday for the American benchmark crude.

Those low prices have forced OPEC and Russia to lower production in recent years, and this year many financially struggling American oil companies have slashed their exploration and production investments to pay down their debts and protect their dividends.

An Era of Cheaper Oil

The new oil will accelerate those trends, energy experts say, even if only for a few years as production declines in older fields in other places.

“This could spell disaster for every producer and producing country,” said Raoul LeBlanc, a vice president at IHS Markit, an energy consultancy, especially if the United States and Iran come to some sort of nuclear deal.

Like the shale boom, the coming supply surge is a sudden change in dynamics. Guyana currently produces no oil at all. Norwegian and Brazilian production has long been in decline. And in Canada, concerns about climate change, resistance to new pipelines and high production costs have curtailed investments in oil-sands fields for five consecutive years.

Production of more oil comes at a time when there is growing acknowledgment by governments and energy investors that not all the hydrocarbons in the ground can be tapped if climate change is to be controlled. But exploration decisions, made years ago, have a momentum that can be hard to stop.

A drilling ship operated by Noble Energy for Exxon Mobil off Guyana. The South American country’s entry into the ranks of oil producers follows a string of major discoveries. Credit…Christopher Gregory for The New York Times

“Legacy decisions keep going,” said John Browne, BP’s former chief executive. “Things happen in different directions because decisions are made at different times.”

The added production in Norway comes despite the country’s embrace of the 2016 Paris climate agreement, which committed nations to cut greenhouse-gas emissions. Its sovereign wealth fund has cut investments in some oil companies, and its national oil company, Equinor, has pledged to increase its investments in wind power.

Equinor, which recently changed its name from Statoil to emphasize its partial pivot to renewable energy, nevertheless defends the new field on its company website, asserting, “The Paris Agreement is quite clear that there will still be a need for oil.”

Norway’s rebound from 19 years of decline began a few weeks ago as Equinor began production in its Johan Sverdrup deepwater field. The field will eventually produce 440,000 barrels a day, increasing the country’s output from 1.3 million barrels a day to 1.6 million next year and 1.8 million in 2021.

In Brazil, after years of scandal and delays, new offshore production platforms are coming online. Production has climbed over the last year by 300,000 barrels a day, and the country is expected to add as much as 460,000 more barrels a day by the end of 2021. In the coming days, Brazil is scheduled to hold a major auction in which some of the largest oil companies will bid for drilling rights in offshore areas with as much as 15 billion barrels of reserves.

In Canada, the 1,000-mile Line 3 pipeline that will take oil from the Alberta fields to Wisconsin, is near completion and awaiting final permitting. Energy experts say that could increase Canadian production by a half million barrels a day, or about 10 percent.

And the most striking change will be in Guyana, a tiny South American country where Exxon Mobil has made a string of major discoveries over the last four years. Production will reach 120,000 barrels a day early next year, rising to at least 750,000 barrels by 2025, and more is expected after that.

Guyana potentially has the most complicated future of the four countries. Its ethnically divided politics are sometimes turbulent, and Venezuela claims a large portion of its territory. But with the oil fields miles offshore, drilling is largely protected. In addition, Venezuela is mired in a political and economic crisis and unlikely to challenge a Chinese state company which has an oil investment in Guyana, along with Exxon Mobil and Hess.

Energy experts say the new production from the four nations will more than satisfy all the growth in global demand expected over the next two years, which is well below the growth rates of recent years before economic expansion in China, Europe and Latin America slowed.

At the same time, new pipelines in Texas are expected to increase United States exports to 3.3 million barrels a day next year, from the current 2.8 million.

That adds up to a vast surplus unless there is a resurgence of global economic growth to stimulate demand, or a prolonged conflict in the Middle East or other disruption to supply.

“To support prices, OPEC is going to have to extend and probably deepen their production cuts for a while,” said David L. Goldwyn, a top State Department energy diplomat during the Obama administration. “Getting the prices up to the point where Aramco can launch its I.P.O. is a big Saudi priority.”

The new barrels on the world market will also put pressure on companies producing in the United States, where profit margins for shale production are slim at current price levels and stock prices are falling.

“If I was in the business I would be scared to death,” said Philip K. Verleger, an energy economist who has served in both Democratic and Republican administrations. “The industry is going to face capital starvation.”

American oil executives express concern that drilling will fade in North Dakota, Oklahoma, Louisiana and Colorado as oil prices drop to as low as $50 a barrel in the next few years. Small companies are expected to merge, while others go bankrupt.

Scott D. Sheffield, chief executive of the Texas-based producer Pioneer Natural Resources, said he expected the growth of United States oil production to ease from 1.2 million barrels a day this year to 500,000 barrels next year and perhaps 400,000 barrels in 2021. Those increases are modest compared with the average increase of a million barrels a day every year from 2010 to 2018.

But Mr. Sheffield said he was optimistic, in part because new supplies coming to market could be offset by production declines in older fields in Mexico and elsewhere after 2021.

“There are no more big, giant new projects except Guyana,” he said. “We just have to be patient for a couple of more years.”

A version of this article appears in print on , Section A, Page 1 of the New York edition with the headline: Needed or Not, Oil Production Is Set to Surge.

Climate Change, Climate science, Keeping Watch on Earth News

How Scientists Got Climate Change So Wrong

Few thought it would arrive so quickly. Now we’re facing consequences once viewed as fringe scenarios.
The New York Times, Opinion, by Eugene Linden, Nov. 8, 2019
Transit workers pumped water out of the South Ferry subway station in Lower Manhattan after Hurricane Sandy in 2012.
Transit workers pumped water out of the South Ferry subway station in Lower Manhattan after Hurricane Sandy in 2012. Credit…Hiroko Masuike/The New York Times

For decades, most scientists saw climate change as a distant prospect. We now know that thinking was wrong. This summer, for instance, a heat wave in Europe penetrated the Arctic, pushing temperatures into the 80s across much of the Far North and, according to the Belgian climate scientist Xavier Fettweis, melting some 40 billion tons of Greenland’s ice sheet.

Had a scientist in the early 1990s suggested that within 25 years a single heat wave would measurably raise sea levels, at an estimated two one-hundredths of an inch, bake the Arctic and produce Sahara-like temperatures in Paris and Berlin, the prediction would have been dismissed as alarmist. But many worst-case scenarios from that time are now realities.

Science is a process of discovery. It can move slowly as the pieces of a puzzle fall together and scientists refine their investigative tools. But in the case of climate, this deliberation has been accompanied by inertia born of bureaucratic caution and politics. A recent essay in Scientific American argued that scientists “tend to underestimate the severity of threats and the rapidity with which they might unfold” and said one of the reasons was “the perceived need for consensus.” This has had severe consequences, diluting what should have been a sense of urgency and vastly understating the looming costs of adaptation and dislocation as the planet continues to warm.

In 1990, the Intergovernmental Panel on Climate Change, the United Nations group of thousands of scientists representing 195 countries, said in its first report that climate change would arrive at a stately pace, that the methane-laden Arctic permafrost was not in danger of thawing, and that the Antarctic ice sheets were stable.

Relying on the climate change panel’s assessment, economists estimated that the economic hit would be small, providing further ammunition against an aggressive approach to reducing emissions and to building resilience to climate change.

As we now know, all of those predictions turned out to be completely wrong. Which makes you wonder whether the projected risks of further warming, dire as they are, might still be understated. How bad will things get?

So far, the costs of underestimation have been enormous. New York City’s subway system did not flood in its first 108 years, but Hurricane Sandy’s 2012 storm surge caused nearly $5 billion in water damage, much of which is still not repaired. In 2017, Hurricane Harvey gave Houston and the surrounding region a $125 billion lesson about the costs of misjudging the potential for floods.

Flooded roads in Beaumont, Tex., after Hurricane Harvey in 2017.
Flooded roads in Beaumont, Tex., after Hurricane Harvey in 2017. Credit…Alyssa Schukar for The New York Times

The climate change panel seems finally to have caught up with the gravity of the climate crisis. Last year, the organization detailed the extraordinary difficulty of limiting warming to 2.7 degrees Fahrenheit (1.5 degrees Celsius), over the next 80 years, and the grim consequences that will result even if that goal is met.

More likely, a separate United Nations report concluded, we are headed for warming of at least 5.4 degrees Fahrenheit. That will come with almost unimaginable damage to economies and ecosystems. Unfortunately, this dose of reality arrives more than 30 years after human-caused climate change became a mainstream issue.

The word “upended” does not do justice to the revolution in climate science wrought by the discovery of sudden climate change. The realization that the global climate can swing between warm and cold periods in a matter of decades or even less came as a profound shock to scientists who thought those shifts took hundreds if not thousands of years.

Scientists knew major volcanic eruptions or asteroid strikes could affect climate rapidly, but such occurrences were uncommon and unpredictable. Absent such rare events, changes in climate looked steady and smooth, a consequence of slow-moving geophysical factors like the earth’s orbital cycle in combination with the tilt of the planet’s axis, or shifts in the continental plates.

Then, in the 1960s, a few scientists began to focus on an unusual event that took place after the last ice age. Scattered evidence suggested that the post-ice age warming was interrupted by a sudden cooling that began around 12,000 years ago and ended abruptly 1,300 years later. The era was named the Younger Dryas for a plant that proliferated during that cold period.

At first, some scientists questioned the rapidity and global reach of the cooling. A report from the National Academies of Science in 1975 acknowledged the Younger Dryas but concluded that it would take centuries for the climate to change in a meaningful way. But not everyone agreed. The climate scientist Wallace Broecker at Columbia had offered a theory that changes in ocean circulation could bring about sudden climate shifts like the Younger Dryas.

And it was Dr. Broecker who, in 1975, the same year as that National Academies report playing down the Younger Dryas, published a paper, titled “Climatic Change: Are We on the Brink of a Pronounced Global Warming?” in which he predicted that emissions of carbon dioxide would raise global temperatures significantly in the 21st century. This is now seen as prophetic, but at the time, Dr. Broecker was an outlier.

Then, in the early 1990s, scientists completed more precise studies of ice cores extracted from the Greenland ice sheet. Dust and oxygen isotopes encased in the cores provided a detailed climate record going back eons. It revealed that there had been 25 rapid climate change events like the Younger Dryas in the last glacial period.

The evidence in those ice cores would prove pivotal in turning the conventional wisdom. As the science historian Spencer Weart put it: “How abrupt was the discovery of abrupt climate change? Many climate experts would put their finger on one moment: the day they read the 1993 report of the analysis of Greenland ice cores. Before that, almost nobody confidently believed that the climate could change massively within a decade or two; after the report, almost nobody felt sure that it could not.”

In 2002, the National Academies acknowledged the reality of rapid climate change in a report, “Abrupt Climate Change: Inevitable Surprises,” which described the new consensus as a “paradigm shift.” This was a reversal of its 1975 report.

“Large, abrupt climate changes have affected hemispheric to global regions repeatedly, as shown by numerous paleoclimate records,” the report said, and added that “changes of up to 16 degrees Celsius and a factor of 2 in precipitation have occurred in some places in periods as short as decades to years.”

The National Academies report added that the implications of such potential rapid changes had not yet been considered by policymakers and economists. And even today, 17 years later, a substantial portion of the American public remains unaware or unconvinced it is happening.

Melt water poured into a fjord in western Greenland this summer when a heat wave that smashed records in Europe moved over the island.
Melt water poured into a fjord in western Greenland this summer when a heat wave that smashed records in Europe moved over the island. Credit…Caspar Haarl’v/Associated Press

Were the ice sheets of Greenland and Antarctica to melt, sea levels would rise by an estimated 225 feet worldwide. Few expect that to happen anytime soon. But those ice sheets now look a lot more fragile than they did to the climate change panel in 1995, when it said that little change was expected over the next hundred years.

In the years since, data has shown that both Greenland and Antarctica have been shedding ice far more rapidly than anticipated. Ice shelves, which are floating extensions of land ice, hold back glaciers from sliding into the sea and eventually melting. In the early 2000s, ice shelves began disintegrating in several parts of Antarctica, and scientists realized that process could greatly accelerate the demise of the vastly larger ice sheets themselves. And some major glaciers are dumping ice directly into the ocean.

By 2014, a number of scientists had concluded that an irreversible collapse of the West Antarctic ice sheet had already begun, and computer modeling in 2016 indicated that its disintegration in concert with other melting could raise sea levels up to six feet by 2100, about twice the increase described as a possible worst-case scenario just three years earlier. At that pace, some of the world’s great coastal cities, including New York, London and Hong Kong, would become inundated.

Then this year, a review of 40 years of satellite images suggested that the East Antarctic ice sheet, which was thought to be relatively stable, may also be shedding vast amounts of ice.

Rifts in the Amery ice shelf in Eastern Antarctica. In September, a section of the shelf broke away, forming a 600-square-mile iceberg.
Rifts in the Amery ice shelf in Eastern Antarctica. In September, a section of the shelf broke away, forming a 600-square-mile iceberg. Credit…Richard Coleman/Agence France-Presse — Getty Images

As the seas rise, they are also warming at a pace unanticipated as recently as five years ago. This is very bad news. For one thing, a warmer ocean means more powerful storms, and die-offs of marine life, but it also suggests that the planet is more sensitive to increased carbon dioxide emissions than previously thought.

The melting of permafrost has also defied expectations. This is ground that has remained frozen for at least two consecutive years and covers around a quarter of the exposed land mass of the Northern Hemisphere. As recently as 1995, it was thought to be stable. But by 2005, the National Center for Atmospheric Research estimated that up to 90 percent of the Northern Hemisphere’s topmost layer of permafrost could thaw by 2100, releasing vast amounts of carbon dioxide and methane into the atmosphere.

For all of the missed predictions, changes in the weather are confirming earlier expectations that a warming globe would be accompanied by an increase in the frequency and severity of extreme weather. And there are new findings unforeseen by early studies, such as the extremely rapid intensification of storms, as on Sept. 1, when Hurricane Dorian’s sustained winds intensified from 150 to 185 miles per hour in just nine hours, and last year when Hurricane Michael grew from tropical depression to major hurricane in just two days.

If the Trump administration has its way, even the revised worst-case scenarios may turn out to be too rosy. In late August, the administration announced a plan to roll back regulations intended to limit methane emissions resulting from oil and gas exploration, despite opposition from some of the largest companies subject to those regulations. More recently, its actions approached the surreal as the Justice Department opened an antitrust investigation into those auto companies that have agreed in principle to abide by higher gas mileage standards required by California. The administration also formally revoked a waiver allowing California to set stricter limits on tailpipe emissions than the federal government.

Even if scientists end up having lowballed their latest assessments of the consequences of the greenhouse gases we continue to emit into the atmosphere, their predictions are dire enough. But the Trump administration has made its posture toward climate change abundantly clear: Bring it on!

It’s already here. And it is going to get worse. A lot worse.

The flooded roadway into the Brooklyn Battery Tunnel in Manhattan after Hurricane Sandy.
The flooded roadway into the Brooklyn Battery Tunnel in Manhattan after Hurricane Sandy. Credit…Andrew Burton/Getty Images

 

Climate Change, Climate science, Keeping Watch on Earth News

Climate Change Will Cost Us Even More Than We Think

Economists greatly underestimate the price tag on harsher weather and higher seas. Why is that?

The New York Times OPINION, by Naomi Oreskes and Nicholas Stern, Oct. 23, 2019.
Credit…Mike McQuade

For some time now it has been clear that the effects of climate change are appearing faster than scientists anticipated. Now it turns out that there is another form of underestimation as bad or worse than the scientific one: the underestimating by economists of the costs.

The result of this failure by economists is that world leaders understand neither the magnitude of the risks to lives and livelihoods, nor the urgency of action. How and why this has occurred is explained in a recent report by scientists and economists at the London School of Economics and Political Science, the Potsdam Institute for Climate Impact Research and the Earth Institute at Columbia University.

One reason is obvious: Since climate scientists have been underestimating the rate of climate change and the severity of its effects, then economists will necessarily underestimate their costs.

But it’s worse than that. A set of assumptions and practices in economics has led economists both to underestimate the economic impact of many climate risks and to miss some of them entirely. That is a problem because, as the report notes, these “missing risks” could have “drastic and potentially catastrophic impacts on citizens, communities and companies.”

One problem involves the nature of risk in a climate-altered world. Right now, carbon dioxide is at its highest concentration in the atmosphere in three million years (and still climbing). The last time levels were this high, the world was about five degrees Fahrenheit warmer and sea level 32 to 65 feet higher. Humans have no experience weathering sustained conditions of this type.

Typically, our estimates of the value or cost of something, whether it is a pair of shoes, a loaf of bread or the impact of a hurricane, are based on experience. Statisticians call this “stationarity.” But when conditions change so much that experience is no longer a reliable guide to the future — when stationarity no longer applies — then estimates become more and more uncertain.

Hydrologists have recognized for some time that climate change has undermined stationarity in water management — indeed, they have declared that stationarity is dead. But economists have by and large not recognized that this applies to climate effects across the board. They approach climate damages as minor perturbations around an underlying path of economic growth, and take little account of the fundamental destruction that we might be facing because it is so outside humanity’s experience.

A second difficulty involves parameters that scientists do not feel they can adequately quantify, like the value of biodiversity or the costs of ocean acidification. Research shows that when scientists lack good data for a variable, even if they know it to be salient, they are loath to assign a value out of a fear that they would be “making it up.”

Therefore, in many cases, they simply omit it from the model, assessment or discussion. In economic assessments of climate change, some of the largest factors, like thresholds in the climate system, when a tiny change could tip the system catastrophically, and possible limits to the human capacity to adapt, are omitted for this reason. In effect, economists have assigned them a value of zero, when the risks are decidedly not. One example from the report: The melting of Himalayan glaciers and snow will both flood and profoundly affect the water supply of communities in which hundreds of millions of people live, yet this is absent from most economic assessments.

A third and terrifying problem involves cascading effects. One reason the harms of climate change are hard to fathom is that they will not occur in isolation, but will reinforce one another in damaging ways. In some cases, they may produce a sequence of serious, and perhaps irreversible, damage.

For example, a sudden rapid loss of Greenland or West Antarctic land ice could lead to much higher sea levels and storm surges, which would contaminate water supplies, destroy coastal cities, force out their residents, and cause turmoil and conflict.

Another example: increased heat decreases food production, which leads to widespread malnutrition, which diminishes the capacity of people to withstand heat and disease and makes it effectively impossible for them to adapt to climate change. Sustained extreme heat may also decrease industrial productivity, bringing about economic depressions.

In a worst-case scenario, climate impacts could set off a feedback loop in which climate change leads to economic losses, which lead to social and political disruption, which undermines both democracy and our capacity to prevent further climate damage. These sorts of cascading effects are rarely captured in economic models of climate impacts. And this set of known omissions does not, of course, include additional risks that we may have failed to have identified.

The urgency and potential irreversibility of climate effects mean we cannot wait for the results of research to deepen our understanding and reduce the uncertainty about these risks. This is particularly so because the study suggests that if we are missing something in our assessments, it is likely something that makes the problem worse.

This is yet another reason it’s urgent to pursue a new, greener economic path for growth and development. If we do that, a happy ending is still possible. But if we wait to be more certain, the only certainty is that we will regret it.

Naomi Oreskes is a professor of the history of science at Harvard and the author, most recently, of “Why Trust Science?” Nicholas Stern is chair of the Grantham Research Institute on Climate Change and the Environment at the London School of Economics and the author of “Why Are We Waiting? The Logic, Urgency and Promise of Tackling Climate Change.”
Climate Change, Climate emergency, Global warming, Greenland, Sea level rise

Something strange is happening to Greenland’s ice sheet

National Geographic, by Madeleine Stone, Sep 18, 2019

What should be like a snowcone is becoming more like a popsicle, speeding up the runoff from the melting ice sheet.

When the remnants of Europe’s second summertime heat wave migrated over Greenland in late July, more than half of the ice sheet’s surface started melting for the first time since 2012. A study published Wednesday in Nature shows that mega-melts like that one, which are being amplified by climate change, aren’t just causing Greenland to shed billions of tons of ice. They’re causing the remaining ice to become denser.

“Ice slabs”—solid planks of ice that can span hundreds of square miles and grow to be 50 feet thick—are spreading across the porous, air pocket-filled surface of the Greenland ice sheet as it melts and refreezes more often. From 2001 to 2014, the slabs expanded in area by about 25,000 square miles, forming an impermeable barrier the size of West Virginia that prevents meltwater from trickling down through the ice. Instead, the meltwater becomes runoff that flows overland, eventually making its way out to sea.

As the ice slabs continue to spread, the study’s authors predict more and more of Greenland’s surface will become a “runoff zone,” boosting the ice sheet’s contribution to global sea level rise and, perhaps, causing unexpected changes.

It’s easy to think of Greenland as a solid, impenetrable hunk of ice. But in reality about 80 percent of the ice sheet’s surface is like a snowcone: A dusting of fresh snowfall covers a thick layer of old snow, called firn, that’s slowly being compressed into glacier ice but still contains plenty of air pockets. When the top of this snow cone melts in the summer, liquid water percolates down into the firn, which soaks it up like a 100-foot-thick sponge.

MacFerrin and his colleagues got their first hint that the firn may be losing its absorbency in the spring of 2012, when they were drilling boreholes through the firn in southwest Greenland. They started finding dense, compacted layers of ice in core after core, just below the seasonal snow layer. It was, MacFerrin says, as if a “turtle shell” had formed over the firn.

MacFerrin and his colleagues immediately wondered whether that shell might be preventing meltwater from percolating into the firn.

“That was May of 2012,” MacFerrin says. “And July was this record-breaking melt year, and we got our answer very quickly.”

That summer, for the first time on record, meltwater from this part of Greenland visibly started to flow away as runoff.

Realizing they had witnessed something significant, the researchers set about drilling more cores over a larger region to see how extensive the ice shell was. They discovered that it spanned a transect 25 miles long and was having widespread effects on local hydrology.

Those findings, published in 2016 in Nature Climate Change, were the springboard for the new study. Using radar data from NASA’s IceBridge airborne campaign, as well as ground-based surveys, MacFerrin and his colleagues have now created a first-of-its-kind map of ice slabs across the entire surface of Greenland.

Based on modelling results, the researchers think the shell began to form and spread widely in the early 2000s. As of 2014, it covered some 4 percent of Greenland’s surface, according to the new analysis. Every summer that extensive melting occurs, it gets thicker and spreads inland to colder, higher ground.

“Every handful of years, these big melt summers are doing a number on the firn,” MacFerrin says. “That’s causing this whole process to grow inland pretty quickly.”

This photo is a segment of a firn core, essentially a baby ice slab that eventually will grow into a meters-thick slab of ice.

PHOTOGRAPH BY DR. KAREN ALLEY

Sea level rise and unexpected consequences 

Ice slabs have already caused Greenland’s runoff zone to expand by about 26 percent, according to the new study. So far the additional runoff has only added about a millimeter to global sea levels. Greenland now contributes a little under a millimeter per year to rising sea levels, through a combination of icebergs breaking off glaciers and melt occurring at the surface and base of the ice sheet.

But if Greenland’s surface hardens more, runoff could rise dramatically. Under a worst-case scenario where carbon emissions continue to climb until the end of the century, the researchers calculated that ice slab proliferation could add up to 3 inches of sea level rise by 2100, boosting the ice sheet’s overall sea level rise contribution by nearly a third. In both a middle-of-the-road scenario where emissions peak by mid-century and the high emissions one, the amount of runoff from Greenland’s interior roughly doubles by century’s end.

But more runoff is only one potential consequence of the transformation taking place in Greenland’s ice. Kristin Poinar, a glaciologist at the University of Buffalo who wasn’t involved in the study, pointed out that slabs of solid ice aren’t nearly as reflective as bright white snowfall.

“And so, if we start getting these ice slabs forming near the ice sheet’s surface, it could potentially…cause the ice sheet to absorb more solar radiation and warm up,” she says. “And that would create more ice slabs.”

And runoff from ice slabs doesn’t have to flow into the ocean, said Indrani Das, a glaciologist at Columbia University who wasn’t involved in the study. She worries about how it could seep into the large crevasses that exist at lower elevations on the ice sheet. From there, the runoff could, potentially, flow all the way down to bedrock, lubricating the zone where the ice makes contact with it.

“That could make the ice sheet flow faster,” Das says, which could cause glaciers to spill their contents into the ocean more quickly, like ice cream sliding off a piece of cake.

To Poinar, the most significant contribution of the new study is that it will allow scientists to improve their projections of future sea level rise, giving coastal communities the information they need to prepare. At the same time, the study highlights the fact that the more carbon we spew into the atmosphere, the more we’re likely to transform Earth’s northern ice sheet in insidious and unexpected ways. And that could have consequences that are difficult to anticipate.

“We have never observed an ice sheet behaving this way before,” Poinar says. “It’s unprecedented in human scientific history.”