Global Warming
Scientists baffled by global warming’s time-out
Temperatures haven't risen this decade, as climatologists expected. Is it sunspots? Ocean currents? Secret volcano?
Polar Bear ( Ursus maritimus). Hudson Bay, Canadian Arctic (Kike Calvo via AP Images)(Credit: Kike Calvo) At least the weather in Copenhagen is likely to be cooperating. The Danish Meteorological Institute predicts that temperatures in December, when the city will host the United Nations Climate Change Conference, will be one degree above the long-term average.
Otherwise, however, not much is happening with global warming at the moment. The Earth’s average temperatures have stopping climbing since the beginning of the millennium, and it even looks as though global warming could come to a standstill this year.
Ironically, climate change appears to have stalled in the run-up to the upcoming world summit in the Danish capital, where thousands of politicians, bureaucrats, scientists, business leaders and environmental activists plan to negotiate a reduction in greenhouse gas emissions. Billions of euros are at stake in the negotiations.
Reached a plateau
The planet’s temperature curve rose sharply for almost 30 years, as global temperatures increased by an average of 0.7 degrees Celsius (1.25 degrees Fahrenheit) from the 1970s to the late 1990s. “At present, however, the warming is taking a break,” confirms meteorologist Mojib Latif of the Leibniz Institute of Marine Sciences in the northern German city of Kiel. Latif, one of Germany’s best-known climatologists, says that the temperature curve has reached a plateau. “There can be no argument about that,” he says. “We have to face that fact.”
Even though the temperature standstill probably has no effect on the long-term warming trend, it does raise doubts about the predictive value of climate models, and it is also a political issue. For months, climate change skeptics have been gloating over the findings on their Internet forums. This has prompted many a climatologist to treat the temperature data in public with a sense of shame, thereby damaging their own credibility.
“It cannot be denied that this one of the hottest issues in the scientific community,” says Jochem Marotzke, director of the Max Planck Institute for Meteorology in Hamburg. “We don’t really know why this stagnation is taking place at this point.”
Just a few weeks ago, Britain’s Hadley Centre for Climate Prediction and Research added more fuel to the fire with its latest calculations of global average temperatures. According to the Hadley figures, the world grew warmer by 0.07 degrees Celsius from 1999 to 2008, and not by the 0.2 degrees Celsius assumed by the United Nations Intergovernmental Panel on Climate Change. And, say the British experts, when their figure is adjusted for two naturally occurring climate phenomena, El Niño and La Niña, the resulting temperature trend is reduced to 0.0 degrees Celsius — in other words, a standstill.
The differences among individual regions of the world are considerable. In the Arctic, for example, temperatures rose by almost three degrees Celsius, which led to a dramatic melting of sea ice. At the same time, temperatures declined in large areas of North America, the western Pacific and the Arabian Peninsula. Europe, including Germany, remains slightly in positive warming territory.
Mixed messages
But a few scientists simply refuse to believe the British calculations. “Warming has continued in the last few years,” says Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research (PIK). However, Rahmstorf is more or less alone in his view. Hamburg Max Planck Institute scientist Jochem Marotzke, on the other hand, says: “I hardly know any colleagues who would deny that it hasn’t gotten warmer in recent years.”
The controversy sends confusing and mixed messages to the lay public. Why is there such a vigorous debate over climate change, even though it isn’t getting warmer at the moment? And how can it be that scientists cannot even arrive at a consensus on changes in temperatures, even though temperatures are constantly being measured?
The global temperature-monitoring network consists of 517 weather stations. But each reading is only a tiny dot on the big world map, and it has to be extrapolated to the entire region with the help of supercomputers. Besides, there are still many blind spots, the largest being the Arctic, where there are only about 20 measuring stations to cover a vast area. Climatologists refer to the problem as the “Arctic hole.”
The scientists at the Hadley Center simply used the global average value for the hole, ignoring the fact that it has become significantly warmer in the Arctic, says Rahmstorf. But a NASA team from the Goddard Institute for Space Studies in New York, which does make the kinds of adjustments for the Arctic data that Rahmstorf believes are necessary, arrives at a flat temperature curve for the last five years that is similar to that of their British colleagues.
Marotzke and Leibniz Institute meteorologist Mojib Latif are even convinced that the fuzzy computing done by Rahmstorf is counterproductive. “We have to explain to the public that greenhouse gases will not cause temperatures to keep rising from one record temperature to the next, but that they are still subject to natural fluctuations,” says Latif. For this reason, he adds, it is dangerous to cite individual weather-related occurrences, such as a drought in Mali or a hurricane, as proof positive that climate change is already fully underway.
“Perhaps we suggested too strongly in the past that the development will continue going up along a simple, straight line. In reality, phases of stagnation or even cooling are completely normal,” says Latif.
Part 2: The difficulties of predicting the climate
Climatologists use their computer models to draw temperature curves which continue well into the future. They predict that the average global temperature will increase by about three degrees Celsius (5.4 degrees Fahrenheit) by the end of the century, unless humanity manages to drastically reduce greenhouse gas emissions. However, no one really knows what exactly the world climate will look like in the not-so-distant future, that is, in 2015, 2030 or 2050.
This is because it is not just human influence but natural factors that affect the Earth’s climate. For instance, currents in the world’s oceans are subject to certain cycles, as is solar activity. Major volcanic eruptions can also curb rising temperatures in the medium term. The eruption of Mount Pinatubo in June 1991, for example, caused world temperatures to drop by an average of 0.5 degrees Celsius, thereby prolonging a cooler climate phase that had begun in the late 1980s.
But the Mount Pinatubo eruption happened too long ago to be related to the current slowdown in global warming. So what is behind this more recent phenomenon?
Weaker solar activity
The fact is that the sun is weakening slightly. Its radiation activity is currently at a minimum, as evidenced by the small number of sunspots on its surface. According to calculations performed by a group of NASA scientists led by David Rind, which were recently published in the journal Geophysical Research Letters, this reduced solar activity is the most important cause of stagnating global warming.
Latif, on the other hand, attributes the stagnation to so-called Pacific decadal oscillation (PDO). This phenomenon in the Pacific Ocean allows a larger volume of cold deep-sea water to rise to the surface at the equator. According to Latif, this has a significant cooling effect on the Earth’s atmosphere.
With his team at the Leibniz Institute of Marine Sciences, Latif has been one of the first to develop a model to create medium-term prognoses for the next five to 10 years. “We are slowly starting to attempt (such models),” says Marotzke, who is also launching a major project in this area, funded by the Federal Ministry for Research and Technology.
Despite their current findings, scientists agree that temperatures will continue to rise in the long term. The big question is: When will it start getting warmer again?
If the deep waters of the Pacific are in fact the most important factor holding up global warming, climate change will remain at a standstill until the middle of the next decade, says Latif. But if the cooling trend is the result of reduced solar activity, things could start getting warmer again much sooner. Based on past experience, solar activity will likely increase again in the next few years.
Betting on warmer temperatures
The Hadley Center group expects warming to resume in the coming years. “That resumption could come as a bit of a jolt,” says Hadley climatologist Adam Scaife, explaining that natural cyclical warming would then be augmented by the warming effect caused by anthropogenic greenhouse gas emissions.
While climatologists at conferences engage in passionate debates over when temperatures will start rising again, global warming’s next steps have also become the subject of betting activity.
Climatologist Stefan Rahmstorf is so convinced that his predictions will be correct in the end that he is willing to back up his conviction with a €2,500 ($3,700) bet. “I will win,” says Rahmstorf.
His adversary Latif turned down the bet, saying that the matter was too serious for gambling. “We are scientists, not poker players.”
Translated from the German by Christopher Sultan
Republican climate folly
As temperatures break records, the GOP holds firm: The less we know about global warming, the better
Frank Gehrke, chief of snow surveys for the Department of Water Resources, stands in a snow-free meadow at Echo Summit, Calif. Warm spring weather, combined with lower then normal precipitation, caused the statewide snowpack water content to be only 40 percent of normal for this time of year. (Credit: AP/Rich Pedroncelli) Whatever adjective you choose — ironic? tragic? ludicrous? — the outcome of a series of budget votes held in the GOP-controlled House on Tuesday was definitely interesting. The chamber was wrangling over a series of amendments to an appropriations bill for the Departments of Commerce and Justice. The battle line was drawn between senior Republicans trying to resist further spending cuts, and young Turks looking to slash and burn.
In every case but one, the senior Republicans (with the help of Democrats) proved victorious. The lone exception? An amendment proposed by Maryland’s Andy Harris, cutting $542,000 in funding for a climate website at the National Oceanic and Atmospheric Administration.
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Andrew Leonard is a staff writer at Salon. On Twitter, @koxinga21. More Andrew Leonard.
Global warming hits home
After a year of freakish and destructive weather, Americans are finally waking up to the dangers of climate change
Houses were severely damaged after Hurricane Irene came through Bethel, Vt. on August 28, 2011 (Credit: U. S. Fish and Wildlife Service - Northeast Region / CC BY 2.0) The Williams River was so languid and lovely last Saturday morning that it was almost impossible to imagine the violence with which it must have been running on August 28, 2011. And yet the evidence was all around: sand piled high on its banks, trees still scattered as if by a giant’s fist, and most obvious of all, a utilitarian temporary bridge where for 140 years a graceful covered bridge had spanned the water.
The YouTube video of that bridge crashing into the raging river was Vermont’s iconic image from its worst disaster in memory, the record flooding that followed Hurricane Irene’s rampage through the state in August 2011. It claimed dozens of lives, as it cut more than a billion-dollar swath of destruction across the eastern United States.
Continue Reading CloseBill McKibben is the Schumann Distinguished Scholar at Middlebury College, and founder of the global climate campaign 350.org. His latest book is "Eaarth: Making a Life on a Tough New Planet.". More Bill McKibben.
Every country for itself
As American power wanes, we're being faced with a dangerous new power vacuum. An expert explains what's next
For the first time in nearly a century, the world doesn’t have a clear set of leaders. A generation ago, the G-7 – France, Germany, Italy, Japan, United Kingdom, United States and Canada – not only powered the global economy, they also, for better or worse, made the decisions that determined the outcome of the entire world. But over the last several years, the dynamic has changed.
According to a widely discussed 2010 report by London’s Standard Chartered Bank, the world has entered a new “‘super-cycle” in which traditional economic hierarchies are being upended. Ever since the financial crisis, the U.S. has lost the economic strength and force of will to be the world’s policeman. The number of Americans, for example, who believe the U.S. should “mind its own business internationally” has spiked to a level unseen since the 1950s. Meanwhile, new powers, like China, India and Brazil, have been unwilling to fill the power vacuum the U.S. has left behind. One could argue that this is a nice change from America’s aggressive past interventionism, but it has also helped create the global stalemate on everything from global warming to humanitarianism in Syria. And it’s a fact that has the potential to radically affect our future, both in positive and negative ways.
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Thomas Rogers is Salon's Arts Editor. More Thomas Rogers.
The Maldives’ ousted president on climate change and tyranny
Ousted in a February coup, Mohamed Nasheed talks global warming, Islamic radicals and "The Island President"
Mohamed Nasheed in "The Island President" It would be too optimistic to claim that the 2009 Copenhagen Summit represented a breakthrough or turning point in the battle against climate change. But it was the first moment when the United States, China and India — the world’s biggest polluters — all agreed in principle to reduce carbon emissions, and as symbolic statements go, that one was pretty big. Copenhagen also catapulted a most unlikely head of state to pop-star status, at least within the worldwide environmental movement. Mohamed Nasheed, who was then the president of the Maldives — Asia’s smallest country, both in area and population — emerged as the developing world’s most charismatic and dynamic spokesman on the causes, and the costs, of global warming.
Continue Reading CloseThe ugly delusions of the educated conservative
Better-educated Republicans are more likely to doubt global warming and believe Obama's a Muslim. Here's why
(Credit: AP Photo/Ross D. Franklin) I can still remember when I first realized how naïve I was in thinking—hoping—that laying out the “facts” would suffice to change politicized minds, and especially Republican ones. It was a typically wonkish, liberal revelation: One based on statistics and data. Only this time, the data were showing, rather awkwardly, that people ignore data and evidence—and often, knowledge and education only make the problem worse.
Someone had sent me a 2008 Pew report documenting the intense partisan divide in the U.S. over the reality of global warming.. It’s a divide that, maddeningly for scientists, has shown a paradoxical tendency to widen even as the basic facts about global warming have become more firmly established.
Chris Mooney is the author of four books, including "The Republican War on Science" (2005). His next book, "The Republican Brain: The Science of Why They Deny Science—and Reality," is due out in April. More Chris Mooney.
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