Taxonomy term

carbon

Methane emissions offset some blue carbon burial benefits

Wetlands are prolific sinks for atmospheric carbon. They pull carbon dioxide out of the air and sequester the carbon in plants, soils and sediments. But there’s a catch: Wetlands also emit methane, an even more potent, albeit far less abundant, greenhouse gas than carbon dioxide. Two new studies, one measuring methane emissions from a rehabilitated freshwater peatland in California and the other looking at emissions from tropical mangrove forests in Australia, are revealing that these so-called “blue carbon” sinks may emit much more methane than previously thought.

03 Oct 2018

Carbon emissions spike when continents rift

The vast majority of Earth’s carbon is stored in the planet’s interior. This buried carbon is not isolated from the surface over geologic timescales, however; some of it is released back into the atmosphere as carbon dioxide and other gases when volcanic eruptions occur above subduction zones or island arcs.

19 Mar 2018

Limestone reservoirs boost volcanic carbon emissions

Volcanoes have been the main source of atmospheric carbon over Earth’s history, with some types of eruptions injecting more carbon into the atmosphere than others. Arc volcanoes, for example, which form in chains along subduction zones, are responsible for up to two-thirds of all volcanic carbon emissions today, and have likely been major contributors for as long as they’ve existed. New research suggests a reason why: These volcanoes draw large amounts of carbon from limestone platforms found along many subduction zones. The finding has implications for how the volcanic carbon cycle affects climate over geologic timescales.

18 Oct 2017

Early spring thaw triggers Arctic greenhouse gas release

During the few short months of Arctic summer, plants and animals race to grow and reproduce, fueling the most active time in the Arctic carbon cycle. But in a new study, researchers examining one corner of the Arctic demonstrate that ecosystems in the icy north aren’t entirely shut down during the offseason, with pulses of carbon dioxide and methane released some years starting during the first spring thaw.

19 Mar 2017

Ocean oxygen levels control seafloor carbon burial

Residual organic carbon from dead marine phytoplankton and other oceanic life can follow two pathways: It can be deeply buried in seafloor sediments or it can be oxidized, either in the water column or in shallow sediment layers. The balance between these two processes and the extent of organic carbon burial over time are crucial in the global carbon cycle, but a complete understanding of the factors and rates controlling organic carbon burial versus oxidation in the oceans has been lacking. In a recent study in Geology, scientists improved on an approach to quantify organic carbon oxidation and provided a glimpse of marine organic carbon burial in the Precambrian, when the oceans were anoxic and Earth’s atmosphere was in the early stages of oxygenation.
 
05 Dec 2015

Buckyballs behind Milky Way mystery

For almost a century, astronomers have observed gaps in the broad spectrum of light reaching Earth from other stars in the Milky Way galaxy. These gaps, called diffuse interstellar bands (DIBs), arise when dust and molecules in interstellar space absorb specific wavelengths of light, thus darkening those bands of light from view. Although hundreds of distinct DIBs have been recognized, scientists have only been able to hypothesize as to the identity of the molecules responsible, until now. In a new study published in Nature, scientists say they have “positively identified” one of the interstellar light-absorbers: nanometer-wide carbon cages named buckminsterfullerene, or “buckyballs.”
 
17 Nov 2015

One-two punch of past warming may hold lessons

Geologists are fond of the saying, “The past is key to the future.” Unfortunately, the past has been a poor guide when it comes to understanding modern climate change. Now, however, a new study suggests that one episode — a spike in global temperatures that occurred about 55 million years ago — may be a better analog than previously thought, and could yield insights into the planet’s future.

 
09 Apr 2015

Down to Earth With: James White

]James White contends that he has one claim to fame: He grew up just 50 kilometers from Dolly Parton in eastern Tennessee. His father worked as a chemist at Oak Ridge National Laboratory, an enclave of science west of Knoxville. Now a chemist himself, White actually has more claims to fame than he is willing to admit. He has co-authored more than 100 peer-reviewed scientific publications; he is the director of the University of Colorado’s Institute of Arctic and Alpine Research (INSTAAR); and he has been named an Institute for Scientific Information highly cited scientist — an honor bestowed on less than 0.5 percent of all publishing researchers.

17 Jun 2013

Source code: the methane race

Ten years ago, John Eiler couldn’t convince anyone to build him his dream machine. He wanted a mass spectrometer that could measure the mass of common gases with extreme precision and sensitivity, but such a device would cost more than a million dollars and might not find a market: The companies that could make it didn’t think they would be able to sell more than just the one to Eiler, which didn’t make it worth their while. Even Eiler didn’t know exactly what problems he could solve with the device, though he had a hunch it would be useful.

10 Jan 2012

Still in a haze: What we don't know about black carbon

Black carbon — fine particles of soot in the atmosphere produced from the burning of fossil fuels or biomass — has been known to be a health hazard for decades, a major contributor to the thick hazes of pollution hovering over cities around the world.

14 Mar 2011

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