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More detailed paleoclimate records, brought to you by lasers

There are a number of ways that nature has preserved climatic clues providing crude telescopes to view Earth’s past. Whether it’s plankton, pollen, or glacial ice, however, the images we see are fuzzy. Some represent summer conditions more than winter. Some can be distorted by shifting winds or ocean currents. All have some limit to their magnification—showing, at best, the average of a year, a century, or a millennium.

The different temporal resolutions come from the rate at which the record accumulates information. A centimeter of ice in an ice core might have come from just one year’s snowfall, while one centimeter of seafloor sediment might have taken a century to pile up. But another part of the limitation comes from how much of the sample we need to use to generate one data point. Now, some researchers have figured out how to get a lot more out of less sample.

Cut to the core

When an ocean sediment core is brought up, it’s usually split in half. One half will be sent into storage for future study, and the other will be carved up into little chunks and bagged for different physical and chemical analyses.

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One of world’s largest landslide deposits discovered in Utah

The Markagrunt gravity slide in Utah includes most of the area between Beaver, Cedar City, and Panguitch.

Some things can be too big to notice, as our flat-Earth-believing ancestors can attest, having failed to work out that the surface of the Earth curves around a sphere. Or, as the saying goes, you can focus on the details of some fascinating trees and miss interesting facts about the forest as a whole.

In southwest Utah, geologists had noticed some pretty cool “trees.” The area had been volcanically active between 21 and 31 million years ago, building up a host of steep, volcanic peaks. A number of huge blocks of rock from these peaks, up to 2.5 square kilometers in area and 200 meters thick, are obviously out of place—they've been interpreted by geologists as the result of many landslides around the volcanoes. In a recent paper in Geology, David Hacker, Robert Biek, and Peter Rowley show that rather than being the result of many individual landslides, these are actually all part of one jaw-droppingly large event.

The deposit, called the Markagunt gravity slide, covers an area about 90 kilometers long and 40 kilometers wide and is hundreds of meters thick. During the event, all of this slid 30 kilometers or more. The scale puts run-of-the-mill landslides—as terrifying and deadly as they can be—to shame.

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Italian court acquits seismologists convicted of manslaughter

An appeals court today overturned the 2012 manslaughter convictions of six Italian earthquake scientists in the wake of a 2009 earthquake that killed 309 people in the town of L’Aquila, as reported by ScienceInsider and NatureNews. Each scientist had been sentenced to six years in prison along with a government official. The official has not been acquitted, but he did have his sentenced reduced to two years.

Amidst a swarm of small earthquakes (and false predictions of major earthquakes by a technician at the nearby National Institute of Nuclear Physics) near the town of L'Aquila in early 2009, the Civil Protection Department convened a meeting of the six scientists. Some public statements resulting from that meeting—specifically statements by Civil Protection Department official Benardo De Bernardinis—were seen to have gone too far, assuring the public that risk of a dangerous earthquake was very low. When a magnitude 6.3 earthquake just six days later killed 309, those statements were blamed for some the deaths as some people apparently failed to leave their homes, which then collapsed.

As Ars reported, a judge ruled that these seven individuals were culpable because of their comments and found the group guilty of manslaughter in 2012. The defendants appealed, resulting in today’s decision.

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Custom evolution boosts an enzyme for power plant carbon capture

We can’t just shutter the world’s fossil fuel power plants tomorrow, but in a perfect world, we could eliminate the greenhouse-enhancing CO2 coming out of the stacks. While it’s not a perfect world just yet, techniques to capture that Co2are being developed—especially for coal plants, which emit the most CO2 per Watt of power generated. Two major obstacles stand between here and there: the infrastructure to store the captured CO2 deep underground (or in other ways) and the cost capturing the CO2.

For traditional coal plants, this involves some way to separate CO2 out of the mix of gases coming through the exhaust stream. A common technique uses amine solutions, which latch on to the CO2 chemically, releasing it later when the solution is heated. That means that some of the heat produced by the burning coal has to be used for the CO2-capture process, rather than producing electricity.

But a new study suggests there may be a way to sacrifice a bit less energy while still capturing the carbon. Its authors evolved one of nature's most efficient enzymes to get it to convert carbon dioxide to carbonate ions within the hot, chemically complex environment where carbon capture takes place.

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IPCC synthesis: We’re headed for “pervasive and irreversible impacts”

Over the weekend, the Intergovernmental Panel on Climate Change (IPCC) released a final draft of the “Synthesis Report” that caps the long road taken to produce its fifth assessment report, which has been released in chunks over the last year. The Synthesis Report, as you might guess, pulls together the main points from the body of the massive report. You won’t find any new information here—the goal is just to summarize the report in the most simple and succinct language possible. Technical, scientific writing is not known for gripping the non-expert reader, so the authors clearly made an effort to communicate the big picture explicitly and frankly.

That big picture, of course, is one in which Earth’s atmosphere and oceans have clearly warmed, with consequences for the hydrologic cycle, the planet’s icy regions, and some weather extremes. Statistically speaking, the report estimates with at least 95 percent confidence that more than half of this warming is due to human activities. The implications for the future are serious. “Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive, and irreversible impacts for people and ecosystems.”

The report reiterates that we’ve already burned about two-thirds of the carbon necessary to warm the Earth 2°C above preindustrial temperatures—a milestone that the international community has agreed to avoid. Staying under 2°C warming will require slashing annual emissions to 40-70 percent below 2010 levels by 2050 and reaching zero emissions by 2100. Most of the scenarios analyzed that achieve this goal rely on some form of Carbon Capture and Sequestration (like pumping CO2 captured from power plants into underground reservoirs) to reduce the impact of the fossil fuels we continue to use.

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As Earth left the last ice age, CO2 rose in fits and starts

The Antarctic ice core, still in the core barrel.

Selecting what kind of record to use when studying Earth’s climate history is a bit like selecting a camera lens from your bag. The choice depends on what you want to see, and your options are limited to what's in the bag. Some climate records are long but low-resolution—a wide-angle lens that shows you the big picture. Other records are short but high-resolution—a telephoto lens that lets you get a good look at that duck over there.

Ice cores have told us a lot about the glacial cycles the Earth has recently been through. Cores of Antarctic ice go back far enough to cover a number of roughly 100,000 year cycles. Greenland ice cores can only stretch back about as far as the previous interglacial warm period, but they show greater detail over short time periods because more snow falls there each year. However, wind-blown dust in Greenland’s ice compromises the tiny samples of atmospheric carbon dioxide locked in bubbles within the ice, making Antarctica the preferred source of information on CO2.

That’s fine for the big picture, but what if we want to learn more about precisely how CO2 changed during the transitions between glacial and interglacial cycles? To study these subtle shifts in Earth’s carbon cycle, you need to zoom in to shorter chunks of time than most Antarctic ice cores can provide.

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A huge tsunami in Hawaii’s past warns of future risk

Simulated tsunamis for earthquakes in several locations.
Rhett Butler

Surfers love Hawaii’s waves, and many dream of catching “the big one.” For most people living in coastal areas vulnerable to tsunamis, though, “the big one” is a bad dream. We’ve seen many devastating events over the years, but our memory is not so long that Mother Nature can’t surprise us. The 2011 tsunami in Japan testified to that.

In 2001, sediment from a past tsunami was found in a sinkhole on the southeast side of the Hawaiian island of Kaua’i. The mouth of that sinkhole is about a hundred meters from the shoreline—and over seven meters above sea level. The largest tsunami measured in the area had been three meters, courtesy of Chile’s monstrous magnitude 9.55 earthquake in 1960. Could it be that an event was big enough to send tsunami waves over seven meters high to Hawaii in the past?

Researchers Rhett Butler, David Burney, and David Walsh simulated a variety of earthquakes around the Pacific to find out. They used a model that simulates the spread of tsunami waves, creating some virtual magnitude 9.0 to 9.6 earthquakes from Alaska to Kamchatka.

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The north pole moved to the North Pole in a single human lifetime

Geology rewards an active imagination. It gives us a lot of tantalizing clues about very different times and places in Earth’s history, leaving us to try to answer “Man, what would that be like?” One of the things that's tough to image involves changing something that most of us never give a second thought—the fact that compasses point north. That’s plainly true today, but it hasn’t always been.

What we call the “north” magnetic pole—the object of your compass’ affection—doesn’t need to be located in the Arctic (it noticeably wanders there, by the way). It feels equally at home in the Antarctic. The geologic record tells us that the north and south magnetic poles frequently trade places. In fact, the signal of this magnetic flip-flopping recorded in the seafloor was the final key to the discovery of plate tectonics, as it let us see how ocean crust forms and moves over time.

That the poles flip is interesting in itself, but “Man, what would that be like?” Does the magnetic pole slowly walk along the curve of the Earth over thousands of years, meaning your compass might have pointed to some part of the equator for long stretches of time? Do the poles weaken to nothing, disappearing for a while before re-emerging in the new configuration? Do they somehow flip in the blink of an eye? Given the number of species that use the Earth’s magnetic field to navigate—especially for seasonal migrations—this is more than an academic curiosity.

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Natural underground CO2 reservoir reveals clues about storage

Reducing our emissions of carbon dioxide quickly enough to minimize the effects of climate change may require more than just phasing out the use of fossil fuels. During the phase-out, we may need to keep the CO2 we're emitting from reaching the atmosphere—a process called carbon capture and sequestration. The biggest obstacle preventing us from using CCS is the lack of economic motivation to do it. But that doesn't mean it's free from technological constraints and scientific unknowns.

One unknown relates to exactly what will happen to the CO2 we pump deep underground. As a free gas, CO2 would obviously be buoyant, fueling concerns about leakage. But CO2 dissolves into the briny water found in saline aquifers at these depths. Once the gas dissolves, the result is actually more dense than the brine, meaning it will settle downward. With time, much of that dissolved CO2 may precipitate as carbonate minerals.

But how quickly does any of this happen? Having answers will be key to understanding how well we really sequester the carbon.

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Why China’s economic growth hasn’t been getting cleaner

It’s no secret that China holds a huge amount of leverage on the future of CO2 emissions. Its incredible economic growth over the last 20 years was accompanied by a boom in greenhouse emissions. Actions to reduce that boom (as well as other pollutants) are in progress, but they haven't had any appreciable effect as of yet.

At the Copenhagen talks, China pledged a lower-carbon economy—reducing the CO2 emitted per unit of GDP (also known as “carbon intensity”) by 40-45 percent below 2005 levels by 2020. And China’s current Five Year Plan (2010-2015) set a goal of reducing carbon intensity by 17 percent while still growing GDP eight percent per year.

But between 2002 and 2009, China’s carbon intensity increased by three percent. What drove that? A new study led by Dabo Guan digs below the national level to take a look at the trends behind carbon intensity. The study suggests that, while huge progress is being made, it's still being swamped by massive growth in capacity.

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