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What connects Earth's largest, hottest desert to its largest tropical rain forest?

The Sahara Desert is a near-uninterrupted brown band of sand and scrub across the northern third of Africa. The Amazon rain forest is a dense green mass of humid jungle that covers northeast South America. But after strong winds sweep across the Sahara, a tan cloud rises in the air, stretches between the continents, and ties together the desert and the jungle. It’s dust. And lots of it.

For the first time, a NASA satellite has quantified in three dimensions how much dust makes this trans-Atlantic journey. Scientists have not only measured the volume of dust, they have also calculated how much phosphorus – remnant in Saharan sands from part of the desert’s past as a lake bed – gets carried across the ocean from one of the planet’s most desolate places to one of its most fertile.

Researchers in Abu Dhabi are testing a pilot device that can store solar energy in sand to improve the efficiency of power plants and provide energy at night.

The technology, developed at the Masdar Institute of Science and Technology, uses gravity to drain sand from a higher basin into a lower one, heating up the sand grains with solar power during the transition. In the lower basin, the energy can be stored and withdrawn at low cost to provide extra energy if needed, for example during peak hours and at night-time.

"Two pilot models of the system have been tested in an effort to prove its efficiency and applicability on a large scale in big projects,” says Nicolas Calvet, an assistant professor at the Masdar institute’s department of mechanical engineering.  

 

One of the hottest new materials is a class of porous solids known as metal-organic frameworks, or MOFs. These man-made materials were introduced in the 1990s, and researchers around the world are working on ways to use them as molecular sponges for applications such as hydrogen storage, carbon sequestration, or photovoltaics.

Now, a surprising discovery by scientists in Canada and Russia reveals that MOFs also exist in nature -- albeit in the form of rare minerals found so far only in Siberian coal mines.

The finding, published in the journal Science Advances, "completely changes the normal view of these highly popular materials as solely artificial, 'designer' solids," says senior author Tomislav FrišÄić, an associate professor of chemistry at McGill University in Montreal. "This raises the possibility that there might be other, more abundant, MOF minerals out there."

The end of last month brought big news in the battle to rein in climate change. The U.S. Environmental Protection Agency announced that greenhouse gas (GHG) emissions from airplanes pose a threat to human health and the environment and therefore are subject to regulation under the Clean Air Act.

The Act was originally passed in 1970 to combat air pollution in the form of airborne lead and mercury, sulfur and nitrogen oxides, carbon monoxide, particulates, and ground-level ozone — to name a few. It was updated in 1990 to include emissions that threaten the ozone layer, and again in 2009 to deal with emissions known to contribute to climate change.

This announcement now clears the way for the EPA to develop rules to regulate aircraft emissions, much as the agency has done for emissions from cars and trucks. Aircraft are responsible for roughly 12 percent of all U.S. transportation-related greenhouse gas emissions, or a little over 3 percent of all U.S. GHG emissions.

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.