Concrete is the world's most-used construction material, and a leading contributor to global warming, producing as much as one-tenth of industry-generated greenhouse-gas emissions. Now a new study suggests a way in which those emissions could be reduced by more than half - and the result would be a stronger, more durable material.
The findings come from the most detailed molecular analysis yet of the complex structure of concrete, which is a mixture of sand, gravel, water, and cement. Cement is made by cooking calcium-rich material, usually limestone, with silica-rich material - typically clay - at temperatures of 1,500 degrees Celsius, yielding a hard mass called "clinker." This is then ground up into a powder. The decarbonation of limestone, and the heating of cement, are responsible for most of the material's greenhouse-gas output.
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Herbivores, not herbicides, may be the most effective way to combat the spread of one of the most invasive plants now threatening East Coast salt marshes, a new Duke University-led study finds. Phragmites australis, or the common reed, is a rapid colonizer that has overrun many coastal wetlands from New England to the Southeast. A non-native perennial, it can form dense stands of grass up to 10 feet high that block valuable shoreline views of the water, kill off native grasses, and alter marsh function.
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This week, dignitaries from U.S. Tribes and Canadian First Nations signed a treaty-the first among them in more than 150 years-to establish intertribal alliances for cooperation in the restoration of American buffalo (or bison) on Tribal/First Nations Reserves or co-managed lands within the U.S. and Canada.
This historic signing of the "Northern Tribes Buffalo treaty" occurred in Blackfeet territory in Browning, Montana, and brought together members of the Blackfeet Nation, Blood Tribe, Siksika Nation, Piikani Nation, the Assiniboine and Gros Ventre Tribes of Fort Belknap Indian Reservation, the Assiniboine and Sioux Tribes of Fort Peck Indian Reservation, the Salish and Kootenai Tribes of the Confederated Salish and Kootenai Indian Reservation, and the Tsuu T’ina Nation.
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The push for increased sustainable methods can be seen everywhere these days — certainly when it comes to local efforts to pare down on what we toss in the landfill. The city of Seattle has also embraced the composting idea with a bit more of a creative edge: In an effort to encourage residents to stop wasting food, the city council passed an ordinance this last Monday that allows households to be fined $1 each time that garbage collectors find more than 10 percent of organic waste in their garbage bins.
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Last year, the people of China emitted more carbon per person than those in the EU, according this year's Global Carbon Budget. The report, updated annually, also found that global emissions jumped 2.5 percent last year and are set to hit a record high of 40 billion tonnes this year. The findings highlight how little global society has done to stem emissions, despite numerous pledges and past global agreements.
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New maps of the sub-ice features in Antarctica and the Arctic, featured in the new edition of The Times Comprehensive Atlas of the World published on 25 September 2014, reveal an unseen world of canyons, lakes, trenches and mountains. The 14th edition of the Atlas also includes a new double page map of the Arctic Ocean, which highlights the dramatic long-term decline of Arctic sea ice cover.
The sub-ice maps draw on bedrock data, provided by the British Antarctic Survey, to show physical features which are obscured by ice cover. In the Antarctic, one of the most striking features is the Gamburtsev Subglacial Mountains, which are as large as the Alps but are currently completely covered by ice.
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