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Massive Antarctic glacier more vulnerable than previously thought

The effect that the expansion of warming ocean water has on sea level is easy to predict. You just plug the value for a given amount of warming into a physical calculation. The contributions from melting glacial ice, however, are much trickier to divine. It depends heavily on fine-scale details, like the shape of the surface beneath the ice, which controls the glacier’s flow toward the sea.

Those fine-scale details aren’t easy to come by—not least because of the difficulty of accessing what can be remote and frigid places. While it’s expensive, field work can fill in key unknowns and reveal some of these glaciers’ histories, informing our estimates of future behavior.

The East Antarctic Ice Sheet isn’t as fragile as its western counterpart, but it is much, much larger. The biggest individual outlet glacier for East Antarctic ice is the Totten Glacier. On its own, the ice behind Totten could raise global sea level more than three meters if it were to melt completely. These frozen giants are generally slow to stir, but like most glaciers around the world, Totten is shrinking. The large floating ice shelf in front of Totten, which holds back the flow of ice like a buttress, is thinning at a rate in the neighborhood of 10 meters per year.

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Politicians can sway voters through town hall events

We have a weird relationship with politicians. Generally, we find them so despicable they couldn’t win a mother’s love—but we make exceptions for the ones that represent our district, of course. Even as we complain that they never actually say anything, we seem to hang on their every word—often just so we can be outraged by it.

So why do they even bother speaking? Do they persuade us to adopt certain positions, or do they merely say what at least half of us want to hear? Persuasiveness seems like a prime attribute for a promising candidate, but there’s very little evidence to back up the idea that they actually manage to change our minds. Sure, we can do some polling to see how public opinion changes over time or try to examine changes in behavior in a laboratory setting, but it’s difficult to extract generalizable conclusions from either.

So Ohio State’s William Minozzi and several colleagues convinced some members of the US Congress to play along with a real-life, randomized trial. Do politicians actually influence opinions and actions when they take part in small “town hall” events? The researchers were going to find out.

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Wind has big impact in shaping arid South American canyons

The beauty of a canyon is principally the artful work of that masterful sculptor, the river. Rivers wouldn’t exist, obviously, without gravity, which also brings material down from the canyon walls. Various types of weathering—reducing rock to loose sediment—also do their part to make the river’s work easier. But there’s another force typically left off the acknowledgements list at the canyon awards that might deserve to be there—wind.

In arid places, wind erosion plays an important role, but its effectiveness is limited. When you come across a feature as dramatic as a canyon, you can be sure water put it there. Wind’s contribution has generally been considered minor. Jonathan Perkins and Noah Finnegan of the University of California Santa Cruz, and Oregon State’s Shanaka de Silva found a way to put that notion to the test.

Where you find water, you can generally find wind, too, so it’s a challenge to tease apart their effects. Constructing an experiment and waiting a million years for clear results isn’t a proposal likely to garner funding. But on the dry western slope of the Andes in northern Chile, the researchers found a natural experiment that conveniently started four million years ago.

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Hints of hydrothermal activity on floor of Enceladus’ ocean

Enceladus makes the short list for most interesting places in the Solar System. After the Cassini mission discovered plumes of water ice erupting from Enceladus’ surface, other work confirmed that a salty sea probably hides below its surface. This raised some obvious questions. What’s it like in that ocean? Could there be life?

Even on its approach to Saturn, however, Cassini was inadvertently gathering evidence. It ran into tiny particles fleeing the gas giant’s gravity at high speed. This wasn't completely unexpected, but what the heck were these particles? Some modeling led researchers to conclude that they likely came from Saturn’s faint “E ring”—the portion of its ring system that we now think is fed by Enceladus’ icy geysers. That means the particles Cassini encountered on its approach would have come from those geysers.

Most of the particles in the “E ring” are ice droplets, but the particles are not. They’re miniscule, at less than 20 nanometers across. While they might once have been held inside ice droplets, they've been freed by the slow erosion of the ice by collisions with charged particles.

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Climate contrarian’s fossil fuel funding ignites disclosure debate

When a researcher’s work is relevant to a publicly controversial issue, you can expect to hear accusations about his or her funding. Those who reject the conclusions of climate science may claim that the desire for federal funding compels scientists to exaggerate the impacts of climate change. Baseless cheap shots aside, funding is something we rightly take seriously. A Pepsi-funded study finding that Pepsi is the best soda, for example, should draw even more scrutiny than an independent study would.

Greenpeace recently obtained the details of the funding of an astrophysicist and climate contrarian named Willie Soon. The information, obtained through a Freedom of Information Act request, is causing a bit of a stir. Soon, who has authored a handful of papers attempting to show that the Sun—not greenhouse gases—is behind recent global warming, had received some $1.2 million over the last ten years from fossil fuel companies, the Charles G. Koch Charitable Foundation, and a source-obscuring system called Donors Trust.

It wasn’t actually news that Soon had gotten fossil fuel industry money to support his research—that's been known for years—but some of the details were new. It appears that Soon failed to make the appropriate conflict-of-interest disclosures required by some of the journals he published in. It was also surprising to discover that some of the funding agreements gave his industry funders the opportunity to review and comment on his publications before they were submitted to journals for review.

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Teach the controversy: Education bills contain a revealing confusion

If you knew absolutely nothing about the bitter public debates over certain scientific issues in the US, the “teach the controversy” bills that keep surfacing would probably sound reasonable and unremarkable. These state bills, which are mostly identical, encourage science teachers to discuss the scientific strengths and weaknesses of scientific theories. Duh, right?

But why are these bills mainly focused on protecting said science teachers from being shut down by their superiors? Why would that happen?

To understand, you need to see that this is just the latest in a very long line of attempts to undermine the teaching of certain scientific topics that the legislators don’t like, especially evolution and climate change. The aim of these bills is to provide cover for teachers who want to teach their students that evolution isn’t a scientific fact and that creationism (possibly stealthed within the supposedly non-sectarian label of “intelligent design”) is a viable scientific alternative.

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How leaky is shale gas production?

The boom in US natural gas production made possible by fracking techniques has raised an awkward question: how much is leaking to the atmosphere before reaching a power plant turbine or your furnace? Natural gas power plants are more efficient than coal-burning plants and emit much less CO2. But methane is a potent, though short-lived, greenhouse gas, so the exact benefit of that trade off depends on the level of leaks from wells and pipelines.

The EPA produces estimates of leakage calculated using limited measurements of typical equipment and production practices. Those estimates put natural gas leakage in the neighborhood of one percent of production— low enough to ensure that the shale gas (fracking) boom is a net positive in terms of climate-changing emissions. A major study sampling new shale gas wells showed that the EPA estimates for well leakage did a pretty good job—at least for those newer wells.

Much has been made, however, of several studies that took a different approach and got very different results. Those studies used methane measurements made from a NOAA airplane upwind and downwind of shale gas fields. At a field outside Denver, that yielded an estimate of 3.1 to 5.3 percent leakage. At a Utah field, leakage was estimated at between 6.2 and 11.7 percent. Near Los Angeles, a leakage rate of 12-22 percent was calculated.

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Shade the planet? The dangers are in the details

When the National Academy of Sciences report on geoengineering, released last week, looked at techniques to reflect some sunlight away from the Earth to counteract anthropogenic warming, the result wasn’t exactly a glowing appraisal. Employing that tactic—generally known as Solar Radiation Management—is fraught with oft-discussed risks. It can result in reduced precipitation and ozone depletion, yet does nothing to curb harmful ocean acidification caused by atmospheric CO2. And, since the substances we're considering (mostly sulfate aerosols) are pretty short-lived in the atmosphere, you’d get a dose of extremely rapid warming if you suddenly pulled the plug.

Harvard’s David Keith and Caltech’s Douglas MacMartin think we’ve often been too sloppy in talking about these risks. That is, we're acting like one scenario—using Solar Radiation Management to completely offset anthropogenic warming as greenhouse gas emissions continue—defines the technique. But other approaches to Solar Radiation Management do not necessarily share the same risks.

For example, interventions can reduce precipitation by cooling the Earth’s surface, while rising CO2 is, on average, increasing precipitation. The net result is that, if enough Solar Radiation Management is used to return the globe to its preindustrial average temperature, precipitation will be reduced to below its preindustrial average. But it's also possible to create a smaller amount of cooling, which doesn’t have to reduce precipitation that far.

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Strange show spotted high above Mars’ surface remains mysterious

Almost three years ago, the Red Planet put on a bit of a show for anyone with a telescope big enough, and an eye trained enough, to spot it. As the Terra Cimmeria region of Mars’ Southern Hemisphere rotated into view, a faint bulge rose above the smooth curve of the planet’s surface. It looked like a cloud, but it was too tall and too weird.

Starting on March 12, 2012, amateur astronomers reported seeing the odd lump on the Martian horizon. Reports continued to pour in over the next 11 days as the lump became even more obvious. It petered out some time before April 1, but a second occurrence was observed between April 6 and April 16. Each time, its form varied from day to day, and it was seen as dawn swept across the region—but not at dusk.

Although the Mars Reconnaissance Orbiter imaged the area daily, it did so in the afternoon, and nothing showed up. But using the images that were captured by amateurs, a group of researchers led by University of the Basque Country’s Agustín Sánchez-Lavega calculated the size of the fuzzy plume. It covered an area some 500 to 1,000 kilometers across and reached as high as 200 to 250 kilometers above the surface—that is, into Mars’ ionosphere and exosphere.

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South American ice chemistry records rise of Incas, arrival of Spanish

Ice cores are often relied on to be natural archives of past climate, capturing information that predates both our measurements and our greenhouse gas emissions. They're a way of having records of the natural world that we don't have a history of. However, natural archives like these can also act as records of human history, either directly (via fossils or artifacts) or indirectly.

In mountainous regions, glacial ice doesn't go as deep into the past as in Greenland or Antarctica, but it can tell stories of the recent past with excellent resolution. Airborne pollutants, for example, stand out sharply in measurements of the ice. They don’t say “pure as the driven snow” for nothing.

Not much of this kind of work has been done in South America, though. Some lake sediment archives have shown the influence of local mining, but the timeline was fuzzy. In a new study, a team led by Chiara Uglietti, now at Switzerland’s Paul Scherrer Institute, has produced a detailed ice core record of air pollution from Peru’s Quelccaya Ice Cap that goes back to the year 793.

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