Emissions on EARTH Magazine

Limestone reservoirs boost volcanic carbon emissions

Fri, 13 Oct 2017 09:44:40 -0400

New research suggests that arc volcanoes, which release large amounts of carbon when they erupt, draw their carbon from limestone platforms found along subduction zones. Credit: K. Cantner, AGI.

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.

Earthquakes make volcanoes more — and less — gassy

Thu, 10 Aug 2017 11:30:57 -0400

Turrialba Volcano in Costa Rica showed an increase in sulfur dioxide emissions after earthquakes. Credit: ©iStockphoto.com/piratedub.

Triggering of volcanic emissions by earthquakes has been observed since antiquity. The Roman naturalist and philosopher Pliny the Elder proposed the link as early as A.D. 77, and in “The Voyage of the Beagle,” Charles Darwin wrote about inland eruptions in Chile closely following an offshore earthquake in 1835. More recent statistical studies show that after large earthquakes, volcanic activity around the world increases. But the lack of robust monitoring equipment at most volcanoes has made it hard to quantify the relationship. In a new study, scientists demonstrate how satellites can be used to track changes in sulfur dioxide emissions from volcanoes after seismic events, offering a potential way to study the often elusive link between seismicity and volcanism.

Smokier U.S. West as climate changes

Tue, 15 Nov 2016 11:14:14 -0500

Jia Coco Liu and her team created an interactive map showing counties in the U.S. West most likely to suffer from high wildfire pollution events and elevated dangerous particulate matter. Credit: khanotations.github.io/smoke-map/.

Extended wildfire seasons and larger and more frequent burns will likely be the consequence of the hotter and drier conditions expected to result from climate change. New research shows that this expected surge in wildfires also poses a growing threat to human health.

No laughing matter: Ocean nitrous oxide emissions greater than thought

Thu, 12 Nov 2015 08:46:09 -0500

High productivity ecosystems like the upwelling zone off the coast of Peru, which once supported an abundant anchovy fishery before overfishing collapsed it in the 1970s and ‘80s, also create oxygen minimum zones where high fluxes of nitrous oxide are produced. Credit: ©Shutterstock.com/Sven Schermer.

Nitrous oxide is a potent greenhouse gas and, since the banning of chlorofluorocarbons in 1987, it has become the main driver of ozone loss from the stratosphere. Most atmospheric nitrous oxide is emitted from agricultural land and soils, but roughly a third is thought to come from the ocean. However, marine sources and sinks of the gas are not well understood.

Comment: Pipe Dreams: What have we learned from the Volkswagen Clean-Diesel scandal?

Mon, 02 Nov 2015 13:42:36 -0500

Side view of the VW Golf TDI clean diesel. Credit: ©Mariordo, CC BY-SA 3.0.

In the last couple of years, we both considered buying a Volkswagen. The company’s “clean-diesel” cars offered great fuel economy and were fun to drive. We could go green without sacrificing performance.

One-two punch of past warming may hold lessons

Mon, 09 Mar 2015 11:27:03 -0400

Cores of ancient soils collected from Wyoming's Bighorn Basin reveal new features of ancient climate change. Credit: Scott Wing, Smithsonian Institution.

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.

Carbon tet still offensive to ozone layer

Tue, 04 Nov 2014 11:13:38 -0500

The ozone hole (purple and blue) over Antarctica, visualized from satellite data, reached its greatest extent in 2006. Levels of ozone-depleting chemicals in the atmosphere have been declining overall in the last 10 to 15 years, although carbon tetrachloride has not dropped off as rapidly as expected. Credit: NASA.

Earth’s ultraviolet light-shielding ozone layer is recovering, according to a report released in September by the World Meteorological Organization and the United Nations Environment Programme. The findings, authored by more than 250 scientists and presented as part of the latest Scientific Assessment of Ozone Depletion (SAOD), suggest the ongoing success of the 1987 Montreal Protocol and its amendments in cutting atmospheric levels of chlorofluorocarbons (CFCs) and other ozone-depleting substances (ODS’s), which have fallen by about 10 to 15 percent overall since peaking in the late 1990s.

Removing predators increases carbon emissions

Tue, 28 May 2013 17:01:11 -0400

Removal of predators, such as this bromeliad-inhabiting damselfly larvae (_Mecistogaster modesta_), raises carbon dioxide concentrations in the bromeliad's natural water pool. Edd Hammill

Habitat loss, overfishing and invasive species can damage ecosystems, but the loss of predators in particular may have worse consequences than previously thought. In a new study, scientists show that the absence of freshwater predators sharply influences an ecosystem’s carbon dioxide emissions.

Carbon and the city: Tracking emissions from megacities

Mon, 21 May 2012 00:08:24 -0400

A monitoring station perched atop the Eiffel Tower is part of the CO2-MEGAPARIS project trying to identify urban emissions sources in Paris, the only European city monitoring carbon dioxide. ©Benh LIEU SONG, Creative Commons Attribution-ShareAlike 3.0 Unported

Sometime in the first century A.D., Rome’s population passed 1 million. It took more than 18 centuries for a city to surpass the 10 million mark, which both New York City and Tokyo did by 1950. Just six decades later, the world now has about 20 such “megacities” with populations of 10 million or more, including the largest, Tokyo, with a population of 35 million.

Where the rubber meets the road

Thu, 05 Jan 2012 06:41:58 -0500

Castlen Kennedy in the Chevy Tahoe outfitted to burn compressed natural gas instead of petroleum-based gasoline. courtesy of the Apache Corporation

Kennedy in front of several Metropolitan Atlanta Rapid Transit Authority compressed natural gas (CNG) buses, with a representative of Atlanta Gas Light. Atlanta has one of the largest CNG public bus fleets in the country. courtesy of Castlen Kennedy

Kennedy chats with a representative of Virginia Natural Gas as she refuels at an older CNG station in Norfolk, Va., owned by the company. courtesy of Castlen Kennedy

Lessons Learned From a Cross-country Road Trip in a Natural Gas Vehicle

In what seems like a replay of a bad 1970s movie — with high oil prices, prominent energy security risks, and fluctuating emissions regulations — Americans are looking for alternatives to gasoline. But this time around, many industrial proponents, investors, experts and energy enthusiasts claim they have a solution: natural gas
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Touting the fuel cost savings, reduced tailpipe emissions and energy security benefits from an abundant domestic resource of unconventional gas trapped in shale formations, proponents are pointing to natural gas vehicles (NGVs) as one solution to the oil puzzle. Thanks in part to the ongoing efforts of oil magnate T. Boone Pickens, and his “Pickens Plan,” which advocates for the conversion of the nation’s heavy-duty truck fleet to natural gas, this relatively clean-burning “prince of fossil fuels” has had a high profile in recent years. If plans to convert heavier vehicles to natural gas enable the construction of more natural gas refueling stations, is it possible that this alternative fuel will become an attractive option for the average passenger vehicle as well?