The Climate Research Group team compared the temperature changes in the Arctic with predictions from computer models that had been run either with or without the extra impact on climate from increasing levels of greenhouse gases. Without the added greenhouse gases, the models predicted that temperatures in the Arctic would stay much the same. Only when the computer models were run with those extra greenhouse gases did the Arctic warm in the way that it has.
Predicting how the sea ice will change and when the Arctic will see ice-free summers is even harder than predicting Arctic temperature changes. Computer models of the sea ice correctly predict that its ice area will decline, but so far they have totally misjudged the speed at which it will happen. That is worrying. Julienne Stroeve of the National Snow and Ice Data Center in Boulder, Colorado, was the first to look at all the climate models and compare them with the real world. The result was shocking, says Stroeve. She summarized her comparison in a graph that has become famous in the sea-ice world.9 Anytime you sit through a presentation on the future of the Arctic, a version of it will always pop up. The graph shows the average of the predictions from thirteen different computer models of the extent of September sea ice year by year, from 1900 through to 2100, and adds a line showing what has really happened.
In 2006, the real sea-ice cover was “thirty years ahead of the ensemble mean model forecast,” Stroeve wrote. And that was before the catastrophic slump in sea-ice cover in 2007 that was repeated in 2008. According to the computer models, the sea ice should not have retreated to the 2007 level until 2055!
“It is happening much faster than expected,” says Stroeve, “and now we have 2007 and 2008, it is even more dramatic.” So what has happened? Stroeve gives a familiar reply. “The ice has just gotten too thin. We might be moving toward a transition period. Some of the models show that once you have thin ice and you get natural variability that hits on it hard and albedo feedback sets in, you can get a very rapid change.”
I went back to Mark Serreze for his view of the state of computer models. As the head of the world’s biggest Arctic ice research laboratory, he packs some authority. Serreze is clearly gripped by his work (he tells me he looks at the latest ice data coming into his institute every single day). He punctuates his account of what is happening with a conspiratorial “OK,” as though he were drawing you ever deeper into a mystery, which he often is.
Curiously, he began his research career looking at a theory that another ice age was on the way. Back in the late 1980s, some scientists worried about possible global cooling. As Serreze says, “In twenty-five years, it has just changed before my eyes. You think that climate change is a slow process but nowhere in the world can you see it as a more visible effect than in the Arctic.”
“We have not quite sorted it out yet,” admits Serreze of the gap between model and reality.10 “If you go back to the climate models and look at what we have seen over the past twenty years, you can see that we are far ahead of schedule in the sea-ice loss. All these climate models are saying that we should be losing ice. There is a consensus that there is a connection to rising greenhouse gases. But none of the models are fast enough in terms of the ice loss that we have seen. Why? One argument is that the climate models are just too insensitive; maybe we haven’t modeled the clouds correctly or something like that. The other argument is that climate variability has boosted the trend.”
I wonder if any of these different parts of “natural climate variability” that made up the perfect storm, including unusual winds and sunshine, are themselves related to rising greenhouse gas levels and might not be quite as “natural” as they might look. “They could be thought of as natural variability working in concert with a greenhouse forcing,” says Serreze. “But what has always puzzled me is that it seems to be a hell of a coincidence. Why is it that all these things are conspiring now? Do we have a complete answer of why we are losing the ice so fast? The short answer is no. I think it’s going to be a while before we really have this figured out, and the problem is the changes have been unfolding faster than our ability to understand them. But we’re catching up.”
The models may have been running well behind the real world but there is a still a lot that can be learned from them. One of the best is the National Center for Atmospheric Research’s model called CCSM3 (Community Climate System Model 3). That model does predict catastrophic changes of the kind we are beginning to see, even though the timing is not right. David Lawrence, a climate modeler who works on CCSM3, has been figuring out what it might tell us. “It simulates these types of events where you get big drops of sea ice over periods of five to ten years, which is definitely not on the slow trend line,” he says. “Maybe that is what’s going to happen in the next decade or so. We may be going into a period where the ice is going to drop substantially and very quickly.”
So that crash of 2007 might be the start of a dramatic downward slide. Lawrence explains that they ran the climate model eight times to generate eight different sets of predictions (or “ensemble members”). It is standard practice to repeatedly run the same model with slightly different starting conditions, and then calculate an average prediction (an “ensemble mean”), because each time the model will give a somewhat different result, thanks to the natural chaos of the world.
That mean prediction is rather like the answer you might give to the question: “How long does it take you to commute to work?” You might reply “thirty minutes.” What you really mean is that it takes thirty minutes on average but on some days it is less, some days it is more, and there was that day it took two hours when there was big accident. Unlike your commute, which happens every day, the future of the sea ice will happen only once. We can’t expect it to be an “average” future. The real future will lie somewhere within the range of the possible.
Within the runs of those eight ensemble members, Lawrence explains that NCAR researchers found nine different “abrupt ice loss events,” the earliest of which hit in 2012 and the latest in 2045. “So the model is saying things like this can occur,” says Lawrence. “I think if we had run the model one hundred times we may very well have had an event that occurred as early as 2007.”
The ups and downs of the run that showed an “abrupt ice event” in 2012 look eerily like the real graph. It is simply running a few years late. The ice disappeared for exactly the reasons that we are seeing now-thinning ice hit by natural variability and the ice-albedo feedback.
That flailing pattern of ups and downs coming out of the computer is unnerving. Uncertainty looks set to rule. In the near future, there may be collapses followed by lulls, and sometimes large recoveries of the ice area, followed by further collapses. Nobody should be surprised if over the coming years and decades there is no simple downward trend in the summer ice minimum. We could have a few years of plateau or recovery. We might all start to think the Arctic is on the mend. We can be certain that the global warming skeptics will be out there shouting “hoax” every year the area of ice does not fall lower than the year before. The computer model shows that a slow and steady decline is not what we should expect at all. There may be lurches downward, pauses, rises, periods of stability, and then further collapses. But what is certain is that the ice is on the way out.
That leads us to the million-dollar question: when? When you ask this question, faces grow grim. Everyone is well aware that we may be witnessing the fastest single environmental catastrophe to hit this planet since the rise of human civilization. There has not been any environmental change on this scale and at this speed anywhere on Earth in the last 2,000 years, especially a change for which humans are to blame. Jim Overland, an oceanographer at the Pacific Marine Environmental Laboratory in Seattle with a long track record in studying the sea ice, began a talk to the American Geophysical Union in 2008 by showing a picture of the retreating ice edge and saying: “I guess I am speaking for the polar bears this morning….”
So when does he think the ice will vanish? Overland’s estimate was 2
030. I asked Mark Serreze. “Before 2040,” he says. David Barber’s view was, “The earlier end of the range of 2013 to 2030.” One way to get the most out of computer models is to select all those that have made the best predictions in recent years and have good sea-ice physics built into them. Muyin Wang of the University of Washington in Seattle, working with Overland, pulled six models out of the twenty-three now available and found that if she looked ahead at their predictions, starting from where the ice has reached (not where models say it should be), then not a lot of time is left. An ice-free summer may occur as early as 2028 and most probably by 2037.11
None of these estimates give us very long, especially compared to the answer “2100” that was standard only a few years ago. But there is one computer modeler who predicts a truly scary date: “between 2010 and 2016.” And he has good reasons to think he may be right.
Wieslaw Maslowski works at the U.S. Naval Postgraduate School in Monterey, California. When I spoke to him he was just heading off to the UN Climate Change Conference in Poznan, Poland, his home country. He was going along, he explained, at the invitation of former U.S. Vice President Al Gore. Maslowski’s models are quite different from the ones we have talked about so far. His is a “regional Pan-Arctic model for the ocean and sea ice” rather than a global climate model.
A key point about his model, he explains, is its very high resolution. “Resolution” in a computer model is like that in a digital camera. If you blow up a digital image enough, you’ll soon see the individual pixels: the camera can’t record any detail within a pixel, it can only show you the average of what was in there. Similarly, climate models break the surface of the planet into “grid squares,” although they are also layered in three dimensions. Each grid square has multiple levels for the different layers of the atmosphere above and the oceans below the planet’s surface. “The global climate models have 100-to-200-kilometer [60-to-120-mile] resolution. The model we are using has a resolution of 9 kilometers [5.6 miles],” explains Maslowski.
High resolution may not matter quite so much when you are modeling the atmosphere where storms, high pressure systems, and so on are large: you only need to look at a weather map to see that they spread over hundreds or even thousands of miles. But down in the ocean and among the ice floes, currents may be only a few miles across, and there are narrow straits in the Arctic where warm and cold waters are flowing in different directions in an area far smaller than a single grid cell in a global climate model.
Maslowski’s model also has many layers in the first twenty-five meters (eighty-two feet) of the ocean to give a more realistic fit for the Arctic’s shallow seas. With its capacity to capture ocean details that climate models blur, it is no surprise that Maslowski sees ocean effects that he thinks others miss. That is why his model produces a different result, he explains. “Many people do not fully understand the importance of the ocean,” he says. “Possibly up to 60 percent or more of the sea-ice melt in the western Arctic region is determined by oceanic heat under the ice.” Plenty of oceanographers agree with him, although you won’t be surprised to hear that the atmospheric scientists remain cool. We are back at that divide.
At the end of the scientific chase, consensus is not perfect, but we are still left in a bleak place. The summer ice is disappearing. It may all be over within a few decades—or it may be over in a few years. The Arctic will be a new world. That is what is really important. Each winter the seas will freeze over with thin, new ice and each summer that ice will mostly vanish again, except for patches here and there in the most favorable locations, most likely among the Canadian islands. Compare that to the thousands of years that the Arctic has been full of thick, stable multiyear ice, rich with life, each summer. An Arctic that freezes over and melts again each year is a completely different place for the creatures and people that live there now. If change happens that fast, it will be the most unimaginable, wrenching challenge for the Arctic’s animals, ecosystems, and people.
There is more to say. Not only are we to blame for the disappearing ice, but we cannot now stop it dead in its tracks by cutting our greenhouse gas emissions. It is too late. Even if a miracle occurred and we suddenly stopped pumping any greenhouse gases into the atmosphere—if industry shut down, if we stopped driving, flying planes, or cutting down forests—the earth would still go on warming for many decades from the greenhouse gases we have put out already. The main greenhouse gas, carbon dioxide, leaves the atmosphere very slowly, and the carbon dioxide we have already added has not yet completed its warming of the earth.
David Beerling, who studies past climates at the University of Sheffield, explains why.12 “Think of the earth as a bit like your oven. If you set the temperature on an oven, it doesn’t just leap to that temperature. The heating element is inefficient and the metal casing takes a long time to warm up. What we have done by adding greenhouse gas in the atmosphere is to very quickly set a new temperature but because the oceans are on average a little over three kilometers deep, there is an enormous amount of energy they can absorb before the land surface and the air temperatures start to rise. An enormous amount of warming will go into the ocean before planetary temperature stops rising.”
Of course, greenhouse gas levels are not falling. Only if we took truly dramatic and immediate action to cut greenhouse gases might there be a chance to keep some of the Arctic summer ice, although its area would still be less than it is now. In April 2009, a study at the National Center for Atmospheric Research (NCAR) suggested that if emissions were cut now and greenhouse gas levels stabilized at 450 parts per million (ppm) by the end of the century, the ice might lose only a further quarter of its area.13 But greenhouse gas levels are already over 380 ppm and on current trends will rise to 750 ppm by 2100, so very urgent worldwide change would be needed. And this prediction is from only one model, while many others show the ice will be gone before 2050.
I asked several of the sea-ice scientists if they thought there was anything else that could be done. “Human beings cannot,” says Maslowski, “but a major volcanic eruption might. That could cool the climate and might be a turning point for the ice.” A big eruption sends so much dust high into the air that it acts as giant sunshade over the earth.
Ron Lindsay from the Polar Science Center at the University of Washington mentioned volcanoes too: “Something like the Mount Pinatubo eruption [in the Philippines in 1991] might bring back the ice for a few years. If you look at the global mean temperature after Pinatubo, you see a big decrease in temperature, it cools the planet. It recovers within two to three years, though. You would need a long period of volcanism. So don’t hold your breath.” “I think going to an ice-free state is inevitable,” says Serreze. “It is just a question of when. You can’t rethicken. It would take too long. It is inevitable now. I hate to say it.”
It takes a few moments to absorb the word “inevitable.” If there is any upside to follow, it comes in the uniquely powerful message that the Arctic is sending. What stronger sign of climate change could there be than millions of square kilometers of white ice turning to dark water in less than a single lifetime? Is there any more dramatic wake-up call?
If we had the eyes for it, we would already be able to see other terrible changes creeping across the planet. The oceans everywhere are becoming more acidic as carbon dioxide dissolves in their waters. At special risk are any sea creatures with shells or skeletons made of calcium carbonate that the acid can dissolve away. Coral reefs are particularly vulnerable, and fewer than half may survive even current carbon dioxide levels.
We can’t see these changes directly, but we have no excuse for inaction. The Arctic has sent a warning that is spelled out in black and white. It is past time to deal with climate change. Otherwise, we will all be using the word “inevitable” a lot more often. And we will all hate saying it.
BORDERS
Chapter Seven
WHO OWNS THE ARCTIC?
When a Russian miniature submarine planted a titanium
flag on the seabed beneath the North Pole in August 2007, panic broke out. Was Russia about to seize control of the Arctic Ocean the old-fashioned way? Canada’s foreign affairs minister Peter MacKay immediately protested: “This isn’t the fifteenth century. You can’t go around the world and just plant flags and say, ‘We’re claiming this territory.’”
Russia’s move came as the five nations facing one another across the Arctic grew more assertive. All had announced that they had rights to enormous areas of the Arctic seas—or at least to the oil and mineral wealth lying at its bottom. A month earlier, Canada’s Prime Minister Stephen Harper had announced plans for a fleet of ice-strengthened patrol vessels and a new Arctic base. His aggressive line on Canada’s Arctic sovereignty was: “We either use it or lose it. And make no mistake, this government intends to use it.” A few months before that, Norway’s minister of defense announced plans to buy thirty jet fighters because of the nation’s “key interests related to the security developments in the High North.” And in early 2008, European Union foreign policy chief Javier Solana joined in, claiming that the flag planting had changed “the geostrategic dynamics of the region with potential consequences for international stability and European security interests.”
Some Russian newspapers more sensibly described the flag planting as a “stunt” and pointed out that two foreign millionaires, one Swedish and one Australian, had gone along on the trip. As a stunt it was a dramatic success. Nations around the world woke up to the political, economic, and strategic significance of the Arctic, and as the months passed they began issuing new policy directives, rereading legal documents, pouring money into mapping claims to the Arctic, and debating how it should be governed. The Arctic will never be the same again.
The European Union was first off the mark with a strategy document in late 2008,1 but it was the world’s superpower that everyone was waiting for. Just before leaving office in January 2009, U.S. President George Bush issued an Arctic National Security Directive, the first in fifteen years.2 Its biggest surprise was the emphasis it put on ratifying the UN Convention on the Law of the Sea, despite decades of Senate opposition. Although 156 nations have ratified the convention, including all the other Arctic nations, and although it has been in force since 1994, U.S. conservatives have long argued that it could restrict U.S. sovereignty. Russia soon responded with its own document laying out that it would robustly defend its energy and shipping interests in the Arctic.3 Other players joined in, too. NATO held a meeting on Arctic security in Iceland at the beginning of January 2009, and the Nordic nations got together to discuss joint air defenses a month later.
After the Ice Page 11