Tag Archives: human activity

Carbon hotspots: Rivers and streams leak more CO2 than thought

The amount of carbon dioxide escaping from rivers and streams into the atmosphere is much larger than previously thought, according to a new study that maps for the first time the flux of CO2 from inland waters worldwide. Published in the journal Nature, the research reveals the major role these waterways play in the global carbon cycle, the authors said.

“This study solidifies the significance of inland waters as conduits of exchange and provides a framework for inclusion of this exchange in regional and global studies,” said lead author Peter A. Raymond, a professor of ecosystem ecology at the Yale School of Forestry & Environmental Studies (F&ES). “Understanding how ecosystems exchange carbon is important, as they currently offset a significant percentage of emissions caused by human activity.” (more…)

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Human Impact Felt on Black Sea Long Before Industrial Era

When WHOI geologist Liviu Giosan first reconstructed the history of how the Danube River built its delta, he was presented with a puzzle.

In the delta’s early stages of development, the river deposited its sediment within a protected bay. As the delta expanded onto the Black Sea shelf in the late Holocene and was exposed to greater waves and currents, rather than seeing the decline in sediment storage that he expected, Giosan found the opposite. The delta continued to grow. In fact, it has tripled its storage rate.

If an increase in river runoff was responsible for the unusual rapid build up of sediment in the delta, says Giosan, the question is, “Was this extraordinary event in the Danube delta felt in the entire Black Sea basin? And if so, what caused it?” (more…)

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Wind Energy

UD study assesses ocean use off Delaware, Maryland and New Jersey coasts

The Center for Carbon-Free Power Integration (CCPI) at the University of Delaware has issued a new report about ocean use off the coast of Delaware and parts of Maryland and New Jersey. The study addresses viable places to locate offshore wind farms, taking into account biological, ecological and other considerations. The report includes feedback from interested groups who attended a November 2011 workshop, as well as input from experts.

“This report demonstrates that the ocean is already active with ecological and human activity,” lead-author Alison Bates said. “It shows what government regulators ought to consider in planning for offshore wind development and the beginning of a way forward for offshore wind developers and existing users to accommodate one another.” (more…)

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Diamonds and Dust for Better Cement

Structural studies at Berkeley Lab’s Advanced Light Source could point to reduced carbon emissions and stronger cements

It’s no surprise that humans the world over use more water, by volume, than any other material. But in second place, at over 17 billion tons consumed each year, comes concrete made with Portland cement. Portland cement provides the essential binder for strong, versatile concrete; its basic materials are found in many places around the globe; and, at about $100 a ton, it’s relatively cheap. Making it, however, releases massive amounts of carbon dioxide, accounting for more than five percent of the total CO2 emissions from human activity.

“Portland cement is the most important building material in the world,” says Paulo Monteiro, a professor of civil and environmental engineering at the University of California at Berkeley, “but if we are going to find ways to use it more efficiently – or just as important, search for practical alternatives – we need a full understanding of its structure on the nanoscale.” To this end Monteiro has teamed with researchers at the U.S. Department of Energy’s Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. (more…)

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U-M Divers Retrieve Prehistoric Wood from Lake Huron

ANN ARBOR, Mich.— Under the cold clear waters of Lake Huron, University of Michigan researchers have found a five-and-a-half foot-long, pole-shaped piece of wood that is 8,900 years old. The wood, which is tapered and beveled on one side in a way that looks deliberate, may provide important clues to a mysterious period in North American prehistory.

“This was the stage when humans gradually shifted from hunting large mammals like mastodon and caribou to fishing, gathering and agriculture,” said anthropologist John O’Shea. “But because most of the places in this area that prehistoric people lived are now under water, we don’t have good evidence of this important shift itself– just clues from before and after the change. (more…)

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Ice Cores Yield Rich History of Climate Change

*Research project completes drilling for the year, reaching two miles below West Antarctic Ice Sheet* 

On Friday, Jan. 28 in Antarctica, a research team investigating the last 100,000 years of Earth’s climate history reached an important milestone completing the main ice core to a depth of 3,331 meters (10,928 feet) at West Antarctic Ice Sheet Divide (WAIS). The project will be completed over the next two years with some additional coring and borehole logging to obtain additional information and samples of the ice for the study of the climate record contained in the core.

As part of the project, begun six years ago, the team, funded by the National Science Foundation (NSF), has been drilling deep into the ice at the WAIS Divide site and recovering and analyzing ice cores for clues about how changes in the concentration of greenhouse gases in the atmosphere have influenced the Earth’s climate over time. (more…)

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