March 25, 2013

Global nitrogen availability consistent for past 500 years, linked to carbon levels


A Kansas State University research team has found that despite humans increasing nitrogen production through industrialization, nitrogen availability in many ecosystems has remained steady for the past 500 years. Their work appears in the journal Nature.
"People have been really interested in nitrogen in current times because it's a major pollutant," said Kendra McLauchlan, assistant professor of geography and director of the university's Paleoenvironmental Laboratory. "Humans are producing a lot more nitrogen than in the past for use as crop fertilizer, and there is concern because excess levels can cause damage. The mystery, though, is whether the biosphere is able to soak up this extra nitrogen and what that means for the future."
Nitrogen is a key component of the ecosystem and the largest regulator of plant growth. It determines how much food, fuel and fiber the land can produce. It also determines how much carbon dioxide plants remove from the atmosphere, and it interacts with several components of the climate system. Excessive amounts of nitrogen in ecosystems contribute to global warming and impairment of downstream ecosystems.

March 24, 2013

Before Dinosaurs' Era, Volcanic Eruptions Triggered Mass Extinction


More than 200 million years ago, a massive extinction decimated 76 percent of marine and terrestrial species, marking the end of the Triassic period and the onset of the Jurassic.
The event cleared the way for dinosaurs to dominate Earth for the next 135 million years, taking over ecological niches formerly occupied by other marine and terrestrial species.
It's not clear what caused the end-Triassic extinction, although most scientists agree on a likely scenario.
Over a relatively short time period, massive volcanic eruptions from a large region known as the Central Atlantic Magmatic Province (CAMP) spewed forth huge amounts of lava and gas, including carbon dioxide, sulfur and methane.This sudden release of gases into the atmosphere may have created intense global warming, and acidification of the oceans, which ultimately killed off thousands of plant and animal species.
Now, researchers at MIT, Columbia University and other institutions have determined that these eruptions occurred precisely when the extinction began, providing strong evidence that volcanic activity did indeed trigger the end-Triassic extinction.
Results of the research, funded by the National Science Foundation (NSF), are published this week in the journal Science.

Study shows resources giveaway in Latin America; Outdated model tramples human rights, environment


A new study reveals that governments in Latin America have returned to natural resources extraction to fuel development—while paying scant attention to the impact mining, oil exploration and other activities have on the environment or on the people who own the land. The study, which reported on both domestic and international investments, was released at the 14th Rights and Resources Initiative Dialogue on Forests, Governance, and Climate Change bringing stakeholders and indigenous, Afro-descendant and rural community leaders from 13 nations to Bogotá this week.
"We seem to have returned to an almost colonial mentality," said Margarita Florez, Executive Director, Asociación Ambiente y Sociedad, whose study reviewed the recent activities impacts of extractive activities on lands owned by Indigenous Peoples, Afro-descendants and other forest communities in Colombia, Panama and Guatemala. "Our governments are being shortsighted. They are undervaluing renewable resources such as forests and water, and are putting the rights of foreign investors before those who have lived and worked the land for generations."
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