Tag Archives: carbon dioxide

Sailing in a Sea of Microbes

Researchers led by Matt Sullivan at the UA are among the first to dive into the world of viruses drifting through the world’s oceans.

Surrounded by the deep blue of the Pacific Ocean stretching from horizon to horizon, a lonely dot is glinting in the sun. It is the aluminum hull of a sailboat, a 118-foot schooner with white sails billowing from two masts.

On the deck, crewmembers and scientists are milling about. Commands are flying back and forth, and soon a strange contraption consisting of tubes clustered around an array of sensors dangling from a crane is lowered into the water, until it disappears in the clear blue depths. (more…)

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Evolution of Earliest Horses Driven by Climate Change

*The hotter it gets, the smaller the animal?*

When Sifrhippus sandae, the earliest known horse, first appeared in the forests of North America more than 50 million years ago, it would not have been mistaken for a Clydesdale.

It weighed in at around 12 pounds–and it was destined to get much smaller over the ensuing millennia.

Sifrhippus lived during the Paleocene-Eocene Thermal Maximum (PETM), a 175,000-year interval of time some 56 million years ago in which average global temperatures rose by about 10 degrees Fahrenheit. (more…)

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Global Extinction: Gradual Doom as Bad as Abrupt

*In “The Great Dying” 250 million years ago, the end came slowly*

The deadliest mass extinction of all took a long time to kill 90 percent of Earth’s marine life–and it killed in stages–according to a newly published report.

It shows that mass extinctions need not be sudden events.

Thomas Algeo, a geologist at the University of Cincinnati, and 13 colleagues have produced a high-resolution look at the geology of a Permian-Triassic boundary section on Ellesmere Island in the Canadian Arctic. (more…)

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Scientist: Temperate Freshwater Wetlands Are ‘Forgotten’ Carbon Sinks

COLUMBUS, Ohio – A new study comparing the carbon-holding power of freshwater wetlands has produced measurements suggesting that wetlands in temperate regions are more valuable as carbon sinks than current policies imply, according to researchers.

The study compared several wetlands at two Ohio wetland sites: one composed of mostly stagnant water and one characterized by water regularly flowing through it. The study showed that the stagnant wetland had an average carbon storage rate per year that is almost twice as high as the carbon storage rate of the flow-through wetland. (more…)

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Sea Cucumbers: Dissolving Coral Reefs?

Washington, D.C. — Coral reefs are extremely diverse ecosystems that support enormous biodiversity. But they are at risk. Carbon dioxide emissions are acidifying the ocean, threatening reefs and other marine organisms. New research led by Carnegie’s Kenneth Schneider analyzed the role of sea cucumbers in portions of the Great Barrier Reef and determined that their  dietary process of dissolving calcium carbonate (CaCO3) from the surrounding reef accounts for about half of at the total nighttime dissolution for the reef. The work is published December 23 by the Journal of Geophysical Research.

Reefs are formed through the biological deposition of calcium carbonate (CaCO3). Many of the marine organisms living on and around a reef contribute to either its destruction or construction. Therefore it is crucial that the amount of calcium carbonate remain in balance. When this delicate balance is disrupted, the reef ceases to grow and its foundations can be weakened. (more…)

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J. Timmons Roberts: What did Durban do for climate?

J. Timmons Roberts, professor of sociology and director of the Center for Environmental Studies, led a group of Brown researchers and students to the United Nations climate change negotiations in Durban, South Africa. On his return, Roberts spoke with Richard Lewis, reflecting on the Durban meetings, the status of research, and the challenges of activism on issues of climate change.

Timmons Roberts, professor and director of the Center for Environmental Studies, has just returned from attending climate talks in Durban, South Africa. Roberts and a delegation from Brown — faculty, postdoctoral researchers, graduate and undergraduate students — witnessed the negotiations up close as observers to ministerial speeches and negotiations. The talks ended with an agreement to extend the greenhouse gas emissions targets set under the Kyoto Protocol and a pledge to work on a replacement treaty incorporating the United States, China, and India.

Roberts spoke with Richard Lewis on the importance of the talks, the need for industrialized countries to compensate developing countries for damages from climate change, and the unique opportunity for people from Brown’s environmental program to attend the talks. (more…)

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New Projection Shows Global Food Demand Doubling by 2050

*Increasing yield in poorer countries could decrease adverse environmental effects*

Global food demand could double by 2050, according to a new projection reported this week in the journal Proceedings of the National Academy of Sciences (PNAS).

The analysis also shows that the world faces major environmental challenges unless agricultural practices change.

Scientists David Tilman and Jason Hill of the University of Minnesota (UMN) and colleagues found that producing the amount of food needed could significantly increase levels of carbon dioxide and nitrogen in the environment, and may cause the extinction of numerous species. (more…)

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