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atmosphere

Carbon Feedback from Forest Soils will Accelerate Global Warming, 26-Year Study Projects

After 26 years, the world’s longest-running experiment to discover how warming temperatures affect forest soils has revealed a surprising, cyclical response: Soil warming stimulates periods of abundant carbon release from the soil to the atmosphere alternating with periods of no detectable loss in soil carbon stores. Overall, the results indicate that in a warming world, a self-reinforcing and perhaps uncontrollable carbon feedback will occur between forest soils and the climate system, adding to the build-up of atmospheric carbon dioxide caused by burning fossil fuels and accelerating global warming. The study, led by Jerry Melillo, Distinguished Scientist at the Marine Biological Laboratory(MBL), appears in the October 6 issue of Science.

What Happened to the Sun over 7,000 Years Ago?

An international team led by researchers at Nagoya University, along with US and Swiss colleagues, has identified a new type of solar event and dated it to the year 5480 BC; they did this by measuring carbon-14 levels in tree rings, which reflect the effects of cosmic radiation on the atmosphere at the time. They have also proposed causes of this event, thereby extending knowledge of how the sun behaves.When the activity of the sun changes, it has direct effects on the earth. For example, when the sun is relatively inactive, the amount of a type of carbon called carbon-14 increases in the earth's atmosphere. Because carbon in the air is absorbed by trees, carbon-14 levels in tree rings actually reflect solar activity and unusual solar events in the past. The team took advantage of such a phenomenon by analyzing a specimen from a bristlecone pine tree, a species that can live for thousands of years, to look back deep into the history of the sun.

Globe-trotting pollutants raise some cancer risks four times higher than predicted

A new way of looking at how pollutants ride through the atmosphere has quadrupled the estimate of global lung cancer risk from a pollutant caused by combustion, to a level that is now double the allowable limit recommended by the World Health Organization.The findings, published this week in the Proceedings of the National Academy of Sciences Early Edition online, showed that tiny floating particles can grow semi-solid around pollutants, allowing them to last longer and travel much farther than what previous global climate models predicted.

Canada's Vast Source of Climate Pollution May Go Bust

The Canadian oil sands are one of the world’s largest sources of climate pollution and America’s biggest source of imported oil. And they may be about to go bust.Canada’s oil sands, also known as tar sands, are the world’s fourth-largest reserve of crude oil. Mining them unleashes massive volumes of carbon dioxide into the atmosphere, easing the way for global warming to blow past 2°C (3.6°F) — levels considered “dangerous” under the Paris Climate Agreement.

Exploring the fate of the Earth's storehouse of carbon

A new study predicts that warming temperatures will contribute to the release into the atmosphere of carbon that has long been locked up securely in the coldest reaches of our planet.Soil and climate expert Katherine Todd-Brown, a scientist at the Department of Energy's Pacific Northwest National Laboratory, is an author of the paper, published in the Dec. 1 issue of the journal Nature, which draws upon data collected through 49 separate field experiments around the world.The research was led by Thomas Crowther, formerly of Yale and now at the Netherlands Institute of Ecology, and colleague Mark Bradford at Yale. Scientists from more than 30 institutions across the globe, including PNNL, collaborated on the study.

Exploring the fate of the Earth's storehouse of carbon

A new study predicts that warming temperatures will contribute to the release into the atmosphere of carbon that has long been locked up securely in the coldest reaches of our planet.Soil and climate expert Katherine Todd-Brown, a scientist at the Department of Energy's Pacific Northwest National Laboratory, is an author of the paper, published in the Dec. 1 issue of the journal Nature, which draws upon data collected through 49 separate field experiments around the world.The research was led by Thomas Crowther, formerly of Yale and now at the Netherlands Institute of Ecology, and colleague Mark Bradford at Yale. Scientists from more than 30 institutions across the globe, including PNNL, collaborated on the study.

Study: Carbon-Hungry Plants Impede Growth Rate of Atmospheric CO2

New findings suggest the rate at which CO2 is accumulating in the atmosphere has plateaued in recent years because Earth’s vegetation is grabbing more carbon from the air than in previous decades.That’s the conclusion of a multi-institutional study led by a scientist from the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). It’s based on extensive ground and atmospheric observations of CO2, satellite measurements of vegetation, and computer modeling. The research is published online Nov. 8 in the journal Nature Communications.

Greenhouse gas-monitoring aircraft keep tabs on the Amazon's rising methane levels

Research led by the National Centre of Earth Observation at the University of Leicester is going to new heights in the atmosphere to get a better handle on methane emitted from wetlands in the Amazon.Using small aircraft flying in an upward spiral and collecting samples of the air, the team has measured the levels of methane in the atmosphere over the Amazon basin in unprecedented detail.In the process they've shown the value of satellite measurements of methane for the region, paving the way for research that will keep better tabs on the greenhouse gas. 

Cornell scientists convert carbon dioxide, create electricity

While the human race will always leave its carbon footprint on the Earth, it must continue to find ways to lessen the impact of its fossil fuel consumption.”Carbon capture” technologies – chemically trapping carbon dioxide before it is released into the atmosphere – is one approach. In a recent study, Cornell University researchers disclose a novel method for capturing the greenhouse gas and converting it to a useful product – while producing electrical energy.Lynden Archer, the James A. Friend Family Distinguished Professor of Engineering, and doctoral student Wajdi Al Sadat have developed an oxygen-assisted aluminum/carbon dioxide power cell that uses electrochemical reactions to both sequester the carbon dioxide and produce electricity.

MIT finds tectonic collisions had major impact on climatic shifts

For hundreds of millions of years, Earth's climate has remained on a fairly even keel, with some dramatic exceptions: Around 80 million years ago, the planet's temperature plummeted, along with carbon dioxide levels in the atmosphere. The Earth eventually recovered, only to swing back into the present-day ice age 50 million years ago. Now geologists at MIT have identified the likely cause of both ice ages, as well as a natural mechanism for carbon sequestration. Just prior to both periods, massive tectonic collisions took place near the Earth's equator — a tropical zone where rocks undergo heavy weathering due to frequent rain and other environmental conditions. This weathering involves chemical reactions that absorb a large amount of carbon dioxide from the atmosphere. The dramatic drawdown of carbon dioxide cooled the atmosphere, the new study suggests, and set the planet up for two ice ages, 80 million and 50 million years ago.