Just when the whole “ClimateGate” affair had retreated from the headlines, other climate scientists have stepped in to shoot themselves in the foot in the public spotlight. In a new slow-simmering controversy that reached major news outlets this week, Intergovernmental Panel on Climate Change (IPCC) chief Rajendra Pachauri admitted that one of the details in the 2007 report was a mistake. Though the goof is a minor one (in that it doesn’t change the conclusion of the report), the backlash probably won’t be, given what happened the last time around.
Specifically, one part of the report states that the Himalayan glaciers are retreating faster than anywhere else in the world, and that there’s a good chance they could totally disappear by 2035. But while it’s true that the glaciers are retreating, the date given is a gross overstatement. “You just can’t accomplish it,” says Jeffrey Kargel from the University of Arizona. “If you think about the thicknesses of the ice – 200-300m thicknesses, in some cases up to 400m thick – and if you’re losing ice at the rate of a metre a year, or let’s say double it to two metres a year, you’re not going to get rid of 200m of ice in a quarter of a century” [BBC News].
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Global warming typically takes the rap for melting glaciers, but in the case of the Himalayan mountain range’s dwindling ice, it could have a co-conspirator: soot. Today, at the American Geophysical Union’s annual meeting, scientists said that the black carbon spewed out as industrial pollution from the heavily populated areas nearby could be a much larger contributor to glacier melt than previously thought.
First, NASA’s William Lau says, atmospheric circulation leaves a layer of soot at the base of the Himalayas, and that soot then combines with dust and forms an opaque cloud that absorbs energy. As this layer heats up in the Himalayan foothills, it rises and enhances the seasonal northward flow of humid monsoon winds, forcing moisture and hot air up the slopes of the majestic mountain range. As these particles rise on the warm, overturning air masses, they produce more rain over northern India, which further warms the atmosphere and fuels this “heat pump” that draws even more warm air to the region [LiveScience].
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Climate change doesn’t affect all places equally, and while Greenland and West Antarctica’s glaciers have started slipping into the sea at an alarming rate, East Antarctica was actually gaining ice. But now that could be changing, as a Nature Geoscience study done with data from NASA’s gravity-measuring satellites called GRACE suggests that the area could now be losing mass.
East Antarctica is far too cold, even in summer, for any appreciable melting to happen. And since a warmer world means more precipitation, any extra snow that falls on East Antarctica stays there indefinitely. But, starting in 2006, GRACE began to detect lower gravity over East Antarctica, suggesting that the ice sheet was getting less massive [TIME].
The scientists note that there is a huge uncertainty in their numbers: GRACE data suggests a 57 billion-ton-per-year loss, plus or minus 52 billion tons. (The reason is that the bedrock beneath Antarctica could be bouncing back slightly with less ice to weigh it down, which would cross up GRACE’s readings.) Some researchers are not convinced that the continent is losing mass, since the margins for error in the team’s analysis range between 5 and 109 billion tonnes of ice loss per year [New Scientist].
While the amount of East Antarctica ice loss remains in doubt, you can’t miss the huge chunks of Antarctic ice that have floated up near New Zealand this week and posed dangers for shipping. This is only the second time in 78 years that large Antarctic icebergs have been sighted so far north. The previous occasion was in late 2006 when icebergs could be seen from the eastern coast of New Zealand’s South Island, even from the hills around Christchurch [CNN].
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Image: flickr / giladr
The glaciers that shine at the top of Mount Kilimanjaro, the highest peak in Africa, could vanish entirely within 15 years, according to a somber new report. Says glaciologist Lonnie Thompson: “Of the ice cover present in 1912 … 85% has disappeared and 26% of that present in 2000 is now gone” [USA Today]. The mountaintop glaciers are both shrinking around the edges and growing thinner, Thompson’s team found. If the current rate of ice loss continues, the mountain could be ice free as early as 2022.
Thompson says his team has fresh evidence that global warming is to blame. As similar changes are occurring on other mountains in Africa, South America, and in the Himalayas, Thompson says that global climate change, not local weather effects, must be responsible for the receding ice. “The fact that so many glaciers throughout the tropics and subtropics are showing similar responses suggests an underlying common cause,” Thompson said [AP].
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After 120,000 years of slumbering in a Greenland glacier beneath almost two miles of ice, an ultra-small bacteria has been resurrected by the patient efforts of scientists. After incubating the bacteria for almost a year in water that was just above freezing temperature, colonies of the tiny purple-brown bacteria began to grow in a petri dish. Researchers say the bacteria’s resilience provides clues to how life can survive in hostile environments like the Arctic–and maybe even other planets.
The Herminiimonas glaciei bug is not the oldest to ever be resurrected, but it’s the first “ultramicrobacteria” to be revived. Ultramicrobacteria, tiny even by bacterial standards, are about 10 to 50 times smaller than the common human intestinal microbe E. coli. Their diminutive size could give the bacteria a survival advantage over other microorganisms. H. glaciei, for example, is thought to have survived in thin capillaries of nutrient-rich water in the Greenland glacier that would have been too tight a fit for larger bacteria [National Geographic News].
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A radar survey conducted between 2004 and 2008 by Japanese, Chinese, and British scientists reveals how the ice on Antarctica grew, and what the land looks like beneath the ice. At the center of the continent, a nearly two-mile-thick slab of ice has clung to Antarctica’s rocky surface for 14 million years; this is the first time scientists have gotten a virtual glimpse beneath the sheet’s surface.
The topography beneath the ice is mountainous, with peaks and valleys like the European Alps, according the study published Nature. Scientists say that 34 million years ago, small glaciers expanded from the mountaintops and shifted to carve out the terrain. To collect the data, scientists drove huge trains of caterpillar tractors in tight lines over Dome A, a plateau of ice at the heart of Antarctica. The tractors carried radars that pinged down through the ice and sent back profiles of the frozen rock landscape below [New Scientist]. Scientists knew the velocity of the radar’s radio waves, so they calculated the depth of the ice by timing how long it took the waves to hit the rock and come back to the surface.
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If global warming melts the West Antarctic ice sheet, the thick slab of ice that covers an area the size of Texas, the situation for coastal dwellers around the world may not be as dire as previously estimated. A new study, which has sparked some debate, suggests that the water released by West Antarctica’s melting glaciers would raise sea levels by about 10 feet, not the 15 to 20 feet that had previously been predicted.
While the results sound like good news, Antarctic experts and the study’s lead author, Jonathan L. Bamber of the Bristol Glaciology Center in England, agreed that the odds of a disruptive rise in seas over the next century or so from the buildup of greenhouse gases remained serious enough to warrant the world’s attention [The New York Times]. They also note that some regions would also experience a larger surge in sea levels than others. “Sea level rise is not uniform across the world’s oceans, partly as a result of disruptions to the Earth’s gravity field,” explained Professor Bamber. “It turns out that the maximum increase in sea level rise is centred at a latitude of about 40 degrees along the Atlantic and Pacific seaboards of North America.” This would include cities such as San Francisco and New York [BBC News].
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Life sure turns up in the darnedest places. The latest discovery comes from Blood Falls, a rusty red discolouration on the face of the Taylor Glacier in Antarctica [that] occasionally gushes forth a transparent, briny, iron-rich liquid that quickly oxidizes and turns red, staining the ice below [Nature News].
The source of that water is an intensely salty lake trapped beneath 1,300 feet of ice, and a new study has now found that microbes have carved out a niche for themselves in that inhospitable environment, living on sulfur and iron compounds. The bacteria colony has been isolated there for about 1.5 million years, researchers say, ever since the glacier rolled over the lake and created a cold, dark, oxygen-poor ecosystem.
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By the year 2100, ocean levels may have risen twice as much as was predicted just two years ago, researchers announced at the International Scientific Congress on Climate Change in Copenhagen. This means that the lives of some 600 million people living on low-lying islands, as well as those living in Southeast Asia’s populous delta areas, will be put at serious risk if climate change is not quickly and radically mitigated [The New York Times]. Meanwhile, a separate study has cataloged the damage that rising seas would do to the California coastline.
Previous estimates of sea level rise from the Intergovernmental Panel on Climate Change didn’t take full account of the rapid melting of mountain glaciers and Greenland and Antarctic ice sheets, researchers in Copenhagen said. Antarctica, in particular, was thought to be little affected by global warming until recent research proved definitively that the southern continent is heating up. Taking into account the new findings, the upper range in the rise of sea levels could be approximately 1 meter (3.28 feet), “possibly more,” by 2100. At the lower end of the spectrum, it appears increasingly unlikely, say the study’s authors, that sea level rise will be much less than a half-meter by 2100…. “Two or three years ago, those making this type of statement were seen as extremists” [The New York Times], says study coauthor Eric Rignot.
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Three months ago 90 rubber duckies set out on a perilous adventure, sliding down deep holes in a Greenland ice sheet that were expected to carry them eventually out to the ocean. In an experiment designed to shed light on the gradual melting of Greenland’s glaciers due to global warming, the duckies were deposited into moulins (tubular holes) in the Jakobshavn Glacier in mid-September by Alberto Behar, a robotics expert at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. The idea was that the ducks would float along the same channels that melt waters do, and wherever they emerged would reveal the path of the disappearing ice [Scientific American].
But thus far the researchers who have been eagerly awaiting news of the duckies’ arrival in the ocean have been disappointed, and they’re now putting out a loud call for sailors, fishermen, and cruise passengers to keep their eyes peeled for bobbing specks of yellow on the waves. The $2 ducks were chosen for their buoyancy and for their durability in low temperatures. Nasa is offering $100 to the first person who finds a duck. The toys are stamped with an email address and the word “reward” in three languages, including Inuit [Telegraph].
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Hope you’re not bored of stories about water ice on Mars: Now that scientists have found it, they can’t seem to stop finding it. Just a few months after the dear, departed Mars Phoenix Lander made history by touching and analyzing water ice beneath the soil near the Martian north pole, researchers using NASA’s Mars Reconnaissance Orbiter have discovered massive glaciers near the equator. The glaciers, buried under rocky debris, are said to be more than three times the size of Los Angeles, up to half a mile thick and skirt the edges of mountains and cliffs [Telegraph].
The glaciers’ presence means that rovers on future scientific missions won’t have to land at the freezing cold poles to study the planet’s ice. The glaciers could even prove helpful as a source of drinkable water to future astronauts exploring Mars. “This says there may be samples of ice within our reach,” [researcher Jim] Head said. “If we’re thinking ahead to human exploration of Mars, it means we could go to some of these places and actually have water ice there” [Wired News]. Astronauts could also make hydrogen fuel from the ice, researchers say.
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Deep beneath the Antarctic ice sheet, floods of water from buried lakes can hurry glaciers along on their slow slide towards the sea, according to a new study that tracked recent floods beneath the Byrd Glacier. “It’s like putting in a squirt of oil,” says Andy Smith of the British Antarctic Survey, who was not involved in this latest study. “The water lubricates the base of the glacier” [New Scientist]. The findings will help researchers understand the movement of glaciers around the world, a matter of great interest to climate scientists who are investigating how rapidly ice sheets may melt into the ocean due to global warming.
Researchers discovered only recently that inaccessible subglacial lakes in Antarctica periodically shed huge quantities of water. Data collected by a satellite launched in 2003 … revealed a complex network of subglacial plumbing in which water periodically cascades from one hidden reservoir to another [AFP]. The water in the lakes remains liquid, despite being buried beneath a mile of ice in some places, due to warmth from the underlying rock. Now, researchers have shown that these hidden floods affect the thick mountains of ice above.
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Climate scientists have long predicted that global warming will melt polar ice sheets and cause sea levels to rise throughout the century, potentially swamping island nations and flooding low-lying coastal cities. But exactly how much ocean waters will rise has yet to be settled. Now, two studies have come out that at first appear to contradict each other, leading to clashing headlines like “An Inconvenient Truth” Exaggerated Sea Level Rise [Telegraph], and Sea Level Rise May Be Twice More Than Expected [Discovery News].
One study seems to downplay the risk of an extreme sea-level rise, while the other hypes it up. But a closer look reveals that the two studies actually bring researchers nearer to scientific consensus.
In the study published in Science [subscription required], researchers examined the hypothesis of a six-foot sea-level rise by 2100, and calculated how quickly the ice sheets in Greenland and Antarctica would have to melt into the oceans to produce this effect. Their calculations showed that the glaciers would have to essentially gallop towards the sea, which seems an unlikely outcome. In Greenland, the glaciers moving into the island’s calving fjords would have to increase their speed to 28.4 miles per year and sustain that speed until the end of the century [Telegraph]. These researchers believe the most plausible scenario is a sea-level rise of between two and six feet within this century. As their results have been compared to more radical estimates like the 20-foot rise mentioned in the documentary film An Inconvenient Truth, the findings are being greeted with relief.
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The deep furrows carved in the sides of Martian craters were most likely formed by snowmelt in the planet’s recent geological past, according to a new study. The findings indicate that seasonal flows of liquid water may have streamed down the craters’ flanks when Mars was a wetter planet, as recently as a few hundred thousand years ago. Today, the Red Planet is a colder and drier place; although the Mars Phoenix Lander found water ice buried under the dirt near the north pole, no liquid water currently exists on the planet, and any ice exposed to air quickly turns into vapor due to the low atmospheric pressure.
The gullies were first sighted several years ago, but researchers couldn’t immediately determine what had caused them. [S]ome scientists proposed that the features were formed either by dry avalanches or by groundwater pushing up from below the surface and running down the sides of craters [SPACE.com]. But in a new study of crater images taken by the Mars orbiters, researchers found evidence that ice and melting snow were the culprits.
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