Back on the Brink: Will the Lead
In Bullets Finally Kill Off the Condor?

by ted williams
The California condor, the largest bird in North America, was saved from extinction by a captive breeding program that increased its numbers in the wild. But now the condor is facing a new and pernicious threat — the lead from bullets used by game hunters.
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Interview: Climate Pioneer’s Son
Ponders a Worrisome CO2 Milestone

Climate scientist Ralph Keeling has followed in the footsteps of his renowned father, Charles David Keeling, who in 1958 became a pioneering figure in humanity’s struggle to combat climate change when he developed an accurate method of measuring CO2 in the atmosphere and tracking its increase. Today, his son is the director of the Scripps CO2 Program, which was founded by his father and last week reported that global carbon dioxide concentrations had passed an alarming milestone of 400 parts per million. In an interview with Yale Environment 360, Ralph Keeling discusses his father’s work, reflects on the meaning of CO2 levels climbing higher than they’ve been in at least 800,000 years, and expresses hope that crossing the 400 ppm mark may play a role in awakening the public to the dangers of runaway climate change. “It feels a little bit like we’re moving into a new era,” said Keeling. “Bringing about change requires people to be aware of what’s going on.”
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17 May 2013: ‘Artificial Forest’ Nanosystem
Mimics Photosynthesis, Researchers Say

U.S. scientists have developed what they say is the first integrated nanosystem capable of replicating the process of photosynthesis, a sort of “artificial forest” that could one day lead to the production of hydrogen that could be used to power fuel cells. Composed of nanowire structures — including silicon “trunks” and titanium oxide “branches” — the system mimics the role played by chloroplasts in promoting photosynthesis in green plants. By assembling the “trees” in a dense array, resembling a miniature forest, the network lowers sunlight reflection and provides more surface area for hydrogen-producing reactions, the scientists say. “We’ve integrated our nanowire nanoscale heterostructure into a functional system that mimics the integration in chloroplasts and provides a conceptual blueprint for better solar-to-fuel conversion efficiencies in the future,” said Peidong Yang, a chemist with the Lawrence Berkeley National Laboratory and co-author of the study, published in the journal NANO Letters. The lab of Daniel Nocera at Harvard University is doing related research into so-called artificial leaves.

16 May 2013: Scientist’s U.S. Road Trip
Reveals Unexpected Methane Emissions

Methane measurements collected during a scientist’s road trip across the U.S. indicate that local emissions of the potent greenhouse gas are higher than previously known in many regions. Using a gas chromatograph mounted to the roof of a rented camper, Ira Leifer of the University of California, Santa Barbara, collected air samples from Florida to California, finding the highest methane concentrations in areas with significant refinery activity — such as Houston, Texas — and in a region of central California with oil and gas production. He found that methane concentrations exceeded the levels estimated by the U.S. Department of Energy, particularly in areas near industrial fossil fuel extraction sites. The results point to the importance of targeting these “fugitive” methane emissions in parallel with efforts to reduce CO2 emissions. Leifer's findings were published in the journal Atmospheric Environment.

Interview: Telling the Life Story of
Ginkgo, the Oldest Tree on Earth

Botanist Peter Crane sees the ginkgo as more than just a distinctive tree with foul-smelling fruits and nuts prized for reputed medicinal properties. To Crane, author of a new book, Ginkgo, the tree is an oddity in nature because it is a single species with no known living relatives; a living fossil that has been essentially unchanged for more than 200 million years; and an inspiring example of how humans can help a species survive. In an interview with Yale Environment 360, Crane, dean of the Yale School of Forestry & Environmental Studies, talks about what makes the ginkgo unique and what makes it smell, how its toughness and resilience has enabled it to thrive as a street tree, and what the ginkgo’s long history says about human life on earth. The ginkgo, which co-existed with the dinosaurs, “really puts our own species — let alone our individual existence — into a broader context,” says Crane.
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15 May 2013: Glaciers on Everest Disappearing
As Temperatures Rise, Snowfall Declines

The glaciers on Mount Everest and the surrounding region have shrunk by 13 percent in the last five decades as temperatures have risen and snowfall has declined in that section of the Himalaya, according to a new study. Using satellite imagery and topographic maps, a team of scientists found that the majority of glaciers on Everest, the world’s tallest mountain, and in the surrounding Sagarmatha National Park are retreating at an accelerating rate. In the last 50 years, the snowline in the Everest region has shifted up by an average of 590 feet (180 meters), said Sudeep Thakuri, a Ph. D. student at the University of Milan and leader of the research team, which presented its findings at a conference in Cancún, Mexico. Because glaciers are melting faster than they are being replenished, researchers say, rock and debris that were previously hidden under snow are now exposed and absorbing heat.

14 May 2013: Shifting Petrel Diets Suggest
Effect of Humans on Ocean Food Web

An analysis of the bones of ancient and modern Hawaiian petrels has revealed that modern petrels, which forage in the open ocean, are eating prey lower on the food chain than in centuries past, a dramatic shift that coincides with the rise of industrial fishing. In tests conducted on petrel bones collected over three decades in the Hawaiian islands, a team of scientists found that the bones from 4,000 to 100 years ago contained higher ratios of nitrogen-15 and nitrogen-14 isotopes than the more recent bones, suggesting that the earlier birds ate bigger prey before changes in the food web composition of the Northeast Pacific. According to the scientists, the nitrogen ratio started to decline in the decades after the early 1950s, when industrial fishing started to extend beyond the continental shelves. “Our bone record is alarming because it suggests that open-ocean food webs are changing on a large scale due to human influence,” said Peggy Ostrom, a zoologist at Michigan State University and co-author of the study, published in the Proceedings of the National Academy of Sciences.

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