New study traces the fate of carbon stored in thawing Arctic soils
As temperatures rise, some of the organic carbon stored in Arctic permafrost meets an unexpected fate—burial at sea. As many as 2.2 million metric tons of organic carbon per year are swept along by a single river system into Arctic Ocean sediment, according to a new study an international team of researchers published in Nature. This process locks away carbon dioxide (CO2) – a greenhouse gas – and helps stabilize the earth’s CO2 levels over time, and it may help scientists better predict how the natural carbon cycle will interplay with the surge of CO2 emissions due to human activities.(more…)
In the perpetual darkness of a limestone cave, UA researchers have discovered a surprisingly diverse ecosystem of microbes eking out a living from not much more than drip water, rock and air. The discovery not only expands our understanding of how microbes manage to colonize every niche on the planet but also could lead to applications ranging from environmental cleanup solutions to drug development.
Hidden underneath the hilly grasslands studded with ocotillos and mesquite trees in southeastern Arizona lies a world shrouded in perpetual darkness: Kartchner Caverns, a limestone cave system renowned for its untouched cave formations, sculpted over millennia by groundwater dissolving the bedrock and carving out underground rooms, and passages that attract tourists from all over the world. (more…)
How did life on Earth get started? Three new papers co-authored by Mike Russell, a research scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., strengthen the case that Earth’s first life began at alkaline hydrothermal vents at the bottom of oceans. Scientists are interested in understanding early life on Earth because if we ever hope to find life on other worlds — especially icy worlds with subsurface oceans such as Jupiter’s moon Europa and Saturn’s Enceladus — we need to know what chemical signatures to look for.
Two papers published recently in the journal Philosophical Transactions of the Royal Society B provide more detail on the chemical and precursor metabolic reactions that have to take place to pave the pathway for life. Russell and his co-authors describe how the interactions between the earliest oceans and alkaline hydrothermal fluids likely produced acetate (comparable to vinegar). The acetate is a product of methane and hydrogen from the alkaline hydrothermal vents and carbon dioxide dissolved in the surrounding ocean. Once this early chemical pathway was forged, acetate could become the basis of other biological molecules. They also describe how two kinds of “nano-engines” that create organic carbon and polymers — energy currency of the first cells — could have been assembled from inorganic minerals. (more…)
Scientists find surprising new answers in wetlands such as the Everglades
Scientists have uncovered one of nature’s long-kept secrets–the true fate of charcoal in the world’s soils.
The ability to determine the fate of charcoal is critical to knowledge of the global carbon budget, which in turn can help understand and mitigate climate change.
However, until now, researchers only had scientific guesses about what happens to charcoal once it’s incorporated into soil. They believed it stayed there.
Surprisingly, most of these researchers were wrong. (more…)
It’s morning, deep in the Amazon jungle. In the still air innumerable leaves glisten with moisture, and fog drifts through the trees. As the sun rises, clouds appear and float across the forest canopy … but where do they come from? Water vapor needs soluble particles to condense on. Airborne particles are the seeds of liquid droplets in fog, mist, and clouds.
To learn how aerosol particles form in the Amazon, Mary Gilles of the Chemical Sciences Division at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and David Kilcoyne of the Lab’s Advanced Light Source (ALS) worked with Christopher Pöhlker of Germany’s Max Planck Institute for Chemistry (MPIC) as part of an international team of scientists led by MPIC’s Meinrat Andreae and Ulrich Pöschl. They analyzed samples of naturally formed aerosols collected above the forest floor, deep in the rainforest. (more…)
The findings provide insight into the chemical processes taking place on Mars and will help aid future quests for evidence of ancient or modern Martian life.
Carbon in some Martian meteorites came from Mars but not from life on Mars, according to new research from an international team that includes a University of Arizona geoscientist.
Molecules containing large chains of carbon and hydrogen – the building blocks of all life on Earth – have been the targets of missions to Mars from Viking to the present day.
Scientists have disagreed about how the organic carbon found in meteorites from Mars was formed and whether or not it came from Mars. (more…)
Scientists from the Woods Hole Oceanographic Institution (WHOI) have conducted a new study to measure levels of carbon at various depths in the Arctic Ocean. The study, recently published in the journal Biogeosciences, provides data that will help researchers better understand the Arctic Ocean’s carbon cycle—the pathway through which carbon enters and is used by the marine ecosystem. It will also offer an important point of reference for determining how those levels of carbon change over time, and how the ecosystem responds to rising global temperatures.
“Carbon is the currency of life. Where carbon is coming from, which organisms are using it, how they’re giving off carbon themselves—these things say a lot about how an ocean ecosystem works,” says David Griffith, the lead author on the study.“If warming temperatures perturb the Arctic Ocean, the way that carbon cycles through that system may change.” (more…)
Almost all the sediment-associated chemical concentrations found in 131 of the nation’s rivers that drain to the Atlantic, Pacific and Gulf Coasts are lower than worldwide averages, according to a new study by the USGS. These coastal rivers are a significant pathway for the delivery of sediment-associated chemicals to the world’s coastal zones and oceans.
“I hope that the results of this new study will remind everyone that it is not only river water that can transport chemicals and pollutants, but also the associated sediment load,” said USGS Director Marcia McNutt. “Our citizens expect high environmental quality as compared with worldwide averages, but clean water alone will not suffice if river sediments are host to toxic heavy metals and concentrated organics that can produce dead zones.” (more…)
