Climate

Ocean bacteria are programmed to alter climate gases
May 17, 2016 07:29 AM - Oregon State University via EurekAlert!

SAR11, the most abundant plankton in the world's oceans, are pumping out massive amounts of two sulfur gases that play important roles in the Earth's atmosphere, researchers announced today in the journal Nature Microbiology.

A Major Source of Air Pollution: Farms
May 16, 2016 07:05 PM - Earth Institute, Columbia University

A new study says that emissions from farms outweigh all other human sources of fine-particulate air pollution in much of the United States, Europe, Russia and China. The culprit: fumes from nitrogen-rich fertilizers and animal waste that combine in the air with industrial emissions to form solid particles—a huge source of disease and death. The good news: if industrial emissions decline in coming decades, as most projections say, fine-particle pollution will go down even if fertilizer use doubles as expected. The study appears this week in the journal Geophysical Research Letters.

Agricultural air pollution comes mainly in the form of ammonia, which enters the air as a gas from heavily fertilized fields and livestock waste. It then combines with pollutants from combustion—mainly nitrogen oxides and sulfates from vehicles, power plants and industrial processes—to create tiny solid particles, or aerosols, no more than 2.5 micrometers across, about 1/30 the width of a human hair. The particles can penetrate deep into lungs, causing heart or pulmonary disease; a 2015 study in the journal Nature estimates they cause at least 3.3 million deaths each year globally.

Retreat of ice sheets followed millennia of methane release
May 14, 2016 07:54 AM - CAGE - Center for Arctic Gas Hydrate, Climate and Environment via Science Daily

Scientists have calculated that the present day ice sheets keep vast amounts of climate gas methane in check. Ice sheets are heavy and cold, providing pressure and temperatures that contain methane in form of ice-like substance called gas hydrate. If the ice sheets retreat the weight of the ice will be lifted from the ocean floor, the gas hydrates will be destabilised and the methane will be released.

Studies conducted at CAGE have previously shown that ice sheets and methane hydrates are closely connected, and that release of methane from the seafloor has followed the retreat of the Barents Sea ice sheet some 20,000 years ago. But is all such release of the potent climate gas bound to be catastrophic?

Not necessarily, according to a new study published in Nature Communications. It shows that the methane was indeed released as the ice sheets retreated. However the seepage did not occur in one major pulse, but over a period of 7000 to 10000 years following the initial release.

 

Early Earth's air weighed less than half of today's atmosphere
May 10, 2016 07:23 AM - University of Washington

The idea that the young Earth had a thicker atmosphere turns out to be wrong. New research from the University of Washington uses bubbles trapped in 2.7 billion-year-old rocks to show that air at that time exerted at most half the pressure of today’s atmosphere.

Middle East drought in historical perspective
May 9, 2016 07:20 AM - Laurie Balbo, Green Prophet

A recent study released by the National Aeronautics and Space Administration (NASA) concludes that the current drought that began in 1998 in the eastern Mediterranean Levant  – which includes Cyprus, Israel, Jordan, Lebanon, Palestine, Syria, and Turkey – is the region’s worst dry spell since 1100 C.E.

NASA scientists reconstructed our regional drought history by studying records of tree rings, from dead and live specimens, across several Mediterranean countries to determine patterns of dry and wet years over a 900-year time span. Tree rings are good indicators of precipitation since dry years cause thin rings while thick rings show when water was plentiful. They concluded that the years between 1998 and 2012 were drier than any other period, and that the drought was likely caused by humans.

Ben Cook, lead author and climate scientist at NASA’s Goddard Institute for Space Studies and the Lamont Doherty Earth Observatory at Columbia University in New York City, said the range of regional weather events has varied widely over the last millennium, but the past twenty years stand out as extreme, falling outside the range of natural variability.

Greenland's ice sheet not losing ice in its interior
May 5, 2016 07:08 AM - Universtiy of Illinois

Scientists studying data from the top of the Greenland ice sheet have discovered that during winter in the center of the world's largest island, temperature inversions and other low-level atmospheric phenomena effectively isolate the ice surface from the atmosphere -- recycling water vapor and halting the loss or gain of ice.

A team of climate scientists made the surprising discovery from three years of data collected at Summit Camp, an arid, glaciated landscape 10,500 feet above sea level in the middle of the Greenland ice sheet.

"This is a place, unlike the rest of the ice sheet, where ice is accumulating," says Max Berkelhammer, assistant professor of earth and environmental sciences at the University of Illinois at Chicago. Berkelhammer is first author on the study, reported in Science Advances, an open-access online publication of the journal Science.

Why aren't hybrid car owners showing more loyalty to hybrids?
April 29, 2016 07:51 AM - Leon Kaye, Triple Pundit

Hybrid cars have come a long way since the first frumpy Toyota Prius debuted in Japan almost 20 years ago. The same can be said for electric cars since GM rolled out its EV1 in the late 1990s, only to backtrack, repossess and destroy all of them, infuriating its fans in the process. There are now dozens of hybrid models, and they enjoyed a surge in saleswhen gasoline prices spiked in 2007 and again in 2012. But more recently, their sales overall have been on the decline. Meanwhile electric vehicles are becoming more sophisticated, are improving their range and have seen sales on the uptick while the automakers have become more competitive in their advertising.

As expected, hybrid cars’ sluggish sales numbers have much to do with the fact that oil prices have been in a two-year slump while conventional gasoline engines keep getting cleaner and more fuel efficient. When hybrids started becoming more popular a decade ago, it was often assumed that when it came time for a new upgrade, owners would stay loyal and trade in one hybrid car for another.

 

Long-term exposure to particulate air pollutants associated with numerous cancers
April 29, 2016 06:52 AM - University of Birmingham

The study between the University of Birmingham and University of Hong Kong, published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, adds to growing concern around the health risks of prolonged exposure to ambient fine particulate matter.

Carbon dioxide fertilization is greening the Earth
April 28, 2016 07:08 AM - Samson Reiny, NASA

From a quarter to half of Earth’s vegetated lands has shown significant greening over the last 35 years largely due to rising levels of atmospheric carbon dioxide, according to a new study published in the journal Nature Climate Change on April 25.

The ohia tree is in trouble
April 25, 2016 01:08 PM - Richard Schiffman, Yale Environment360

The ʻohiʻa is Hawaii’s iconic tree, a keystone species that maintains healthy watersheds and provides habitat for numerous endangered birds. But a virulent fungal disease, possibly related to a warmer, drier climate, is now felling the island’s cherished `ohi`a forests.

Hawaii’s isolation, 2,390 miles from the North American mainland, has given the island chain a unique array of species found nowhere else, including the ʻohiʻa lehua, an evergreen in the myrtle family with delicate pom-pom-shaped flowers composed of clusters of showy stamens in a range of hues from red and orange to pale yellow. In 2010, homeowners on the Big Island of Hawaii began reporting that ʻohiʻa in their upland rainforest were dying without apparent cause. Researchers named the mysterious condition “Rapid ʻOhiʻa Death” (ROD). 

On Google Earth, you can see the telltale brown streaks in the Puna forest reserve, Hawaii's largest remaining upland rainforest located on the slope of Kilauea volcano, where many ʻohiʻa lehua (Metrosideros polymorpha) trees have already succumbed. If you scroll over 60 miles to the west to the other side of the island, the green canopy behind Kealakekua Bay on the Kona coast — where Captain James Cook first set foot on Hawaii and was later killed — is pocked with the bleached skeletons of dead and dying trees. 

Scenes like these have become commonplace in the American West, where several conifer species, weakened by long-term drought and warmer temperatures, have been decimated by bark beetles. Researchers are wondering if climate change may also have stressed ʻohiʻa trees, perhaps helping to trigger the current outbreak on Hawaii. 

The fungus clogs the vascular system of the trees, making them wilt and die as if from a drought.

An overall decrease in trade winds has created drier conditions in recent years in parts of the islands, at the same time that rising temperatures have warmed things up in the cool upland forests where ʻohiʻa thrive. 

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