Science & Technology
22 May 2015:
Many Trees in Southeast U.S.
Closely Related to Tree Species in Asia
DNA studies show that more than half the trees and shrubs in southern Appalachia can trace their ancestry to eastern Asia.
A flowering dogwood tree
Based on molecular studies of more than 250 species of trees and shrubs from Georgia to Virginia, researchers at Duke University found close ties between East Asian species, such as dogwoods, and species in the southeastern U.S. Forests throughout the northern hemisphere were joined together by the supercontinent Laurasia as recently as 180 million years ago. Then, as the great northern land mass broke into continents, eras of glaciation wiped out various tree species. Forest remnants hung on in China, Japan, small parts of Europe, and Appalachia, which explains the similarity in tree species. The research was published in the American Journal of Botany.
14 May 2015:
Biologically Inspired Coating
Will Improve Solar Panels, Researchers Say
Key characteristics of moths’ eyes, which are anti-reflective, and lotus leaves, which are water-repellant, inspired a new type of glass coating that could significantly improve the efficiency of solar panels, say researchers at Oak Ridge National Laboratory
. The extremely durable coating can be customized to be fog-resistant, anti-reflective, and superhydrophobic — meaning it repels water drops so efficiently that they barely make contact with the solar panel surface, literally bouncing off and carrying away dirt and dust that hamper performance. The key component is a nanostructured layer of glass film that, under a microscope, has a porous texture resembling coral, which helps the solar cells absorb more light, the researchers say. Reflecting less sunlight means a 3 to 6 percent increase in light-to-electricity conversion efficiency and power output, studies show. The coating can be fabricated using standard industry techniques, the researchers say, making it easy and inexpensive to scale up and incorporate in current products.
06 May 2015:
Backyard Bird Feeders May Put
Native Species at a Disadvantage, Study Says
Backyard bird feeders tend to attract aggressive, introduced bird species while discouraging native species that eat
A sparrow eats at a backyard bird feeder.
insects and nectar, essentially restructuring urban bird communities and skewing them toward non-native species, a new study
says. Data based on nearly 600 surveys of 18,000 birds from 33 species in New Zealand show that yards with bird feeders tended to attract non-native omnivores such as house sparrows, spotted doves, and blackbirds. Outdoor areas without bird feeders had significantly more native bird species such as the grey warbler, whose diet consists mainly of insects. Although the population trends reversed when feeders were removed, the researchers say that over time bird feeders in urban areas likely give non-native bird species a competitive and reproductive edge over native species.
05 May 2015:
Pollen May Play Surprising
Role in Climate and Cloud Formation
Grains of pollen may be seeding clouds and affecting the planet's climate in unexpected ways, University of Michigan researchers
Grains of pollen can break into even smaller particles.
write in the journal Geophysical Research Letters
. Scientists had assumed that pollen particles were too large to remain in the atmosphere long enough to interact with the sun's radiation or trigger cloud formation. The study found, however, that pollen grains are capable of disintegrating into much smaller particles and that exposure to humidity can accelerate pollen's breakdown. Using a cloud-making laboratory chamber, the researchers showed that six common types of pollen — ragweed and oak, pecan, birch, cedar, and pine trees — could break into particles small enough to draw moisture and form clouds. "What happens in clouds is one of the big uncertainties in climate models right now," author Allison Steiner said.
30 Apr 2015:
Volcanic Eruption in Chile Could
Have an Effect on Climate, NASA Data Show
Calbuco volcano, which erupted in southern Chile last week for the first time since 1972, has been injecting climate-changing
Sulfur dioxide from Calbuco volcano
gases directly into an upper layer of the atmosphere, NASA satellite data
show. The particularly explosive eruption shot sulfur dioxide, an acrid-smelling gas that can cause respiratory problems at ground level, up into the stratosphere, where it reacts with water vapor to create sulfate aerosols that reflect sunlight and can sometimes have a slight cooling effect. So far, Calbuco has released an estimated 0.3 to 0.4 million tons of sulfur dioxide (SO2) as high as 13 miles, where it will last much longer and travel much farther than if released closer to the earth's surface. The SO2 will gradually convert to sulfate aerosol particles, but it is not clear yet whether there will be a cooling effect associated with Calbuco's eruption, researchers say.
24 Apr 2015:
Long-Term CO2 Record by Keeling
Named National Historic Chemical Landmark
The Keeling Curve — a long-term record of rising carbon dioxide in the planet’s atmosphere — will be named a National Historic
Chemical Landmark, the American Chemical Society announced
yesterday. The late geochemist Charles David Keeling began collecting precise, systematic data on atmospheric CO2 concentrations at Hawaii's Mauna Loa Observatory in 1958. Since then, the rigorous and continuous measurements have become the most widely recognized record of humans' impact on the planet, helping to illustrate the link between rising CO2 levels from burning fossil fuels and global warming. Other works highlighted by National Historic Chemical Landmark program include the discovery of penicillin, deciphering of the genetic code, and the works of Rachel Carson, Thomas Edison, and George Washington Carver.
Interview: Oklahoma’s Clear Link
Between Earthquakes and Energy
In recent years, Oklahoma has experienced a stunning increase in the number of earthquakes. Yet despite numerous
studies to the contrary, state officials have remained skeptical of the link between this seismic boom and oil and gas activity. That ended last month with the announcement by the Oklahoma Geological Survey that oil and gas wastewater injection wells were, indeed, the “likely” cause of “the majority” of that state’s earthquakes. Oklahoma geologist Todd Halihan, who has examined this issue, welcomed the announcement. In an interview with Yale Environment 360
, Halihan outlines some ways that the abnormal seismic activity in Oklahoma might be tamped down. But he also explains why he believes the problem has no quick or easy fixes.
Read the interview.
20 Apr 2015:
Record Amount of E-Waste
Generated Globally in 2014, Report Finds
A record amount of electronic waste was discarded in 2014, with a total of 41.8 million tons of personal electronics and household
2014 saw a record amount of e-waste.
appliances hitting landfills worldwide, a new report
from the United Nations University found. The highest per-capita totals of so-called "e-waste" came from Scandinavian and European countries — Norway topped the list, followed by Switzerland, Iceland, and Denmark — and China and the U.S. were responsible for the largest volumes overall. Nearly 60 percent of e-waste by weight came from electronic components and wiring in large and small kitchen, bathroom, and laundry appliances, and 7 percent was discarded mobile phones, calculators, personal computers, and printers, the report said. It also found that less than one-sixth of all discarded electronics were properly recycled, and an estimated $52 billion in gold, copper, silver, and recoverable materials went to waste.
17 Apr 2015:
New Mapping Tool Could
Lower Cost of Finding Geothermal Energy
A new online mapping tool could help governments and investors evaluate the geothermal energy potential for locations around
the globe through satellite measurements, lowering the risks and costs involved in developing this clean energy source, its creators say. The tool
uses gravity measurements from European Space Agency (ESA) satellites to look for certain characteristics unique to geothermal reservoirs, including areas with thin crusts, subduction zones, and young magmatic activity. This helps determine which locations are most likely to possess geothermal energy potential, narrowing the search — and cost — for prospectors. The project, which is a partnership between the ESA and the International Renewable Energy Agency (IRENA), will "help make a strong business case for geothermal development where none existed before,” said a director at IRENA.
16 Apr 2015:
Researchers Discover New
Source of Methane in the Arctic Ocean
A large reservoir of methane — a greenhouse gas many times more potent than carbon dioxide — was recently discovered on
Knipovich Ridge in the Arctic Ocean
Knipovich Ridge in the central Arctic Ocean, according to
research published in the journal Geology
. The methane in this deposit is locked up in icy crystals of water and gas called hydrates, and it was produced by abiotic geological processes rather than by microbes breaking down organic matter, as most methane is, the authors explain. Until now, scientists had not known that hydrates could contain this type of methane. "Up to 15,000 gigatons of carbon may be stored in the form of hydrates in the ocean floor, but this estimate is not accounting for abiotic methane," said co-author Jürgen Mienert. "So there is probably much more."
15 Apr 2015:
Entries Invited for e360
Contest For Best Environmental Videos
The second annual Yale Environment 360 Video Contest is now accepting entries. The contest honors the best environmental videos. Entries must be videos that focus on an environmental issue or theme, have not been widely viewed online, and are a maximum of 15 minutes in length. Videos that are funded by an organization or company and are primarily about that organization or company are not eligible. The first-place winner will receive $2,000, two runners-up will each receive $500, and all winning entries will be posted on Yale Environment 360
. The contest judges will be Yale Environment 360
editor Roger Cohn, New Yorker
writer and e360
contributor Elizabeth Kolbert, and documentary filmmaker Thomas Lennon. The deadline for entries is June 15, 2015.
08 Apr 2015:
Clay Shows Promise in
Capturing CO2 from Power Plants
Common clay can be just as effective as more advanced materials in capturing carbon dioxide emissions
from power plants, according to research by Norwegian and Slovak scientists. One particular type of clay mineral, known as smectite, was especially effective in absorbing CO2 emissions, the researchers said in the journal Scientific Reports.
One possible use for clay would be to incorporate it into filters or scrubbers in smokestacks at power plants, the scientists said. They said their research into clay’s CO2-absorbing capabilities is preliminary and would not be available for commercial use anytime soon. But the scientists said clay offers many benefits compared to some other expensive and potentially toxic CO2-scrubbing materials.
27 Mar 2015:
Metals Used in High Tech
Are Becoming Harder to Find, Study Says
Metals critical to newer technologies such as smartphones, infrared optics, and medical imaging will likely become harder
This chart shows the criticality of 62 metals.
to obtain in coming decades, according to
Yale researchers, and future products need to be designed to make reclaiming and recycling those materials easier. The study, the first to assess future supply risks to all 62 metals on the periodic table, found that many of the metals traditionally used in manufacturing — zinc, copper, aluminum, lead, and others — show no signs of vulnerability. But some metals that have become more common in technology over the last two decades, such as rare earth metals
, are available almost entirely as byproducts, the researchers say. "You can't mine specifically for them; they often exist in small quantities and are used for specialty purposes," said Yale scientist Thomas Graedel. "And they don't have any decent substitutes."
25 Mar 2015:
Dutch Energy Company Heats
Homes With Custom-Built Computer Servers
A Dutch energy company is installing radiator-sized computer servers — which infamously generate large amounts of
A radiator-sized computer server installed in a home.
waste heat as they churn out data — in residential homes to offset energy costs, company representatives said
this week. In the trial program, Rotterdam-based Eneco has equipped a handful of houses with custom-built computer servers designed to heat rooms as the servers process data for a variety of corporate computing clients. Eneco and the company behind the radiator-servers, Nerdalize
, expect each one to reduce a home's heating expenses by roughly $440 over the course of a year. Eneco will cover all computing-related energy costs, the company said, but they expect the program to reduce server maintenance costs by up to 55 percent through preventing complications that arise when servers overheat. In summer months, the server-radiators will redirect excess heat outside the home, its designers say.
16 Mar 2015:
El Niño and La Niña Can Predict
Severity of Tornado Season, Study Says
El Niño and La Niña conditions can help predict the frequency of tornadoes and hail storms in some of the most
Tornado near El Reno, Okla., in May 2013.
susceptible regions of the U.S., new research
published in the journal Nature Geoscience
shows. Scientists have been using El Niño and La Niña conditions, which can be identified months before the climate cycles actually develop, to make more accurate forecasts of droughts, flooding, and hurricane activity. Now, a team of researchers says they can also forecast how active the spring tornado season will be based on the state of El Niño or La Niña in December, and sometimes even earlier. Moderately strong La Niña events lead to more tornadoes and hail storms over portions of Oklahoma, Texas, Kansas, and other parts of the southern U.S., the study shows, whereas El Niño patterns suppress the storms. Scientists have detected El Niño conditions over the past few weeks, which indicates that this spring will be a relatively quiet one for severe storms in the southern U.S., the authors say.
11 Mar 2015:
Warming To Sharply Increase
For Remainder of 21st Century, Paper Says
Within a decade, the earth — and particularly the northern hemisphere — will begin warming at rates unprecedented in the last 1,000 to 2,000 years, according to new research
in the journal Nature Climate Change
. Examining the rate of temperature increases in 40-year intervals over the past 2,000 years, the scientists concluded that temperatures had fluctuated up or down by about 0.2 degrees F over each interval. In the past 40 years, however, warming has approached 0.4 degrees F per decade. And beginning in 2020, temperatures could start to rise by 0.7 degrees F per decade and continue at that rate until at least 2100. Warming will be especially pronounced in the Arctic, where temperatures are expected to soar by 1.1 degrees F by 2040. The scientists warned that such greenhouse gas-driven warming is moving the planet into an unstable climatic state.
03 Mar 2015:
Photographs of Amazon Forest
Added to Google Street View Collection
Detailed views of the Amazon rainforest, its rivers, and indigenous communities are the latest additions to Google's
"Street View" collection, the company announced
this week. The imagery — captured while boating down 500 kilometers of rivers, walking along 20 kilometers of trails, and ziplining through dense forest — reveals stunning views
of the Amazon from the top of its canopy to the forest floor. The photos also capture daily life in 17 communities of local people who live deep within the rainforest and along the Rio Mariepauá, one of the Amazon River's largest tributaries. The images were collected in partnership with the conservation organization Amazonas Sustainable Foundation, which hopes that sharing in-depth photographs of the area will help promote conservation efforts.
Interview: How Climate Change
Helped Lead to Conflict in Syria
Before Syria devolved into civil war, that country experienced its worst drought on record. The consequences of this disaster
included massive crop failures, rising food prices, and a mass migration to urban areas. In a new study
in the Proceedings of the National Academy of Sciences
, researchers suggest the drought and its ensuing chaos helped spark the Syrian uprising. They make the case that climate change was responsible for the severity of the drought. Colin Kelley, a climatologist at the University of California, Santa Barbara, was the study’s lead author. In an interview with Yale Environment 360
, Kelley explains that long-term precipitation and soil temperature trends in Syria and the rest of the region correlate well with climate change models, demonstrating, he says, that the record-setting drought can’t be attributed to natural variability.
Read the interview.
26 Feb 2015:
Heat-Trapping Effects of
CO2 Measured in Nature for First Time
Scientists have long understood how carbon dioxide traps heat in the atmosphere and contributes to global warming, but the phenomenon had not been directly documented
at the earth's surface outside of a laboratory — until now. Writing in the journal Nature
, researchers present 11 years of field data on carbon dioxide's capacity to absorb thermal radiation emitted from the surface of the earth. The results agree with theoretical predictions of the greenhouse effect associated with fossil fuel combustion, researchers say, and provide further confirmation that calculations used in climate models are on track when it comes to representing the impact of CO2 emissions. "We see, for the first time in the field, the amplification of the greenhouse effect because there's more CO2 in the atmosphere to absorb what the earth emits in response to incoming solar radiation," says Daniel Feldman, a scientist at Berkeley Lab and lead author of the study.
23 Feb 2015:
Large-scale Pumping Can
Return Oxygen To Deep Waters, Study Finds
A team of Danish and Swedish scientists reports
that they have restored oxygen to the waters
Deploying instruments in Byfjord, Sweden.
of a deep fjord that had suffered from a long-term lack of oxygen. The researchers used large pumps to mix oxygen-rich surface water into the deeper parts of the fjord's water column — which had long been anoxic due to its depth and geological setting — and after only two months higher oxygen concentrations became detectable in the bottom waters. "In the later phase of the experiment the entire water column began to look healthy," the researchers said, noting that bacterial species that live in well-oxygenated waters had begun to appear. Low oxygen levels make waters uninhabitable to most forms of life, and anoxic waters often harbor only a few types of bacteria, some of which produce significant levels of greenhouse gases.
16 Feb 2015:
Space-Based Measurments Can
Track Global Ocean Acidity, Researchers Say
An international team of scientists has developed new methods for studying the acidity of the oceans from space,
Global ocean alkalinity measured from space.
according to research
published in the journal Environmental Science and Technology
. Currently, scientists must rely on measurements taken from research vessels and sampling equipment deployed in oceans to determine acidity — which rises as the oceans absorb CO2 from the atmosphere — but this approach is expensive and geographically limited. The new techniques use satellite-mounted thermal cameras to measure ocean temperature and microwave sensors to measure salinity. Together these measurements can be used to assess ocean acidification more quickly and over much larger areas than has been possible before.
12 Feb 2015:
Mange in Yellowstone Wolves
Documented Through Thermal Images
Researchers with the U.S. Geological Survey are using thermal video cameras to study how mange is affecting
Thermal image of a wolf with mange on its legs.
wolves in Yellowstone National Park, as shown in this video
. Mange is a highly contagious skin disease caused by mites that burrow into the skin of dogs and wolves, causing infections, hair loss, irritation, and intense itching. The urge to scratch can be so overwhelming that the wolves neglect resting and hunting, researchers say
, leaving them vulnerable to hypothermia, malnutrition, and dehydration, which can eventually lead to death. Thermal imagery allows scientists to document the extent of hair loss and the actual loss of heat associated with different stages of infection. Red patches on a wolf's legs, as shown in this image, indicate rapid heat loss caused by mange.
11 Feb 2015:
Learning About Geoengineering
Spurs More Agreement on Climate, Study Says
Geoengineering, an experimental series of technologies aimed at counteracting the effects of climate change, could potentially diminish political polarization over global warming, according to new research
. Roughly 3,000 participants in a study displayed more open-mindedness toward evidence of climate change and more agreement on the significance of such evidence after learning about geoengineering technologies, according to a study conducted by researchers at Yale and other universities. Participants became more polarized when they were told that curbing climate change would require reducing greenhouse gas emissions, the researchers report. The findings come after a report this week from the U.S. National Research Council
recommended limited government-sponsored research into the use of sulfate aerosols, a potential geoengineering strategy known as albedo modification.
06 Feb 2015:
Maine’s Iconic Lobsters
Face Threats From Ocean Acidification
Maine’s lobster fishery, worth $1.7 billion
to the state and a vital source of employment, could be
threatened by acidifying ocean waters
A Maine lobster
and rising sea temperatures, according to a new report. The report
, issued by a state commission, called increasingly acidic ocean waters — caused by the absorption of CO2 from the atmosphere — an “urgent matter” that needs to be addressed by state and local governments and the fishing infustry. Facing the prospect that increasing acidity could interfere with the ability of lobsters to make their shells, the commission set forth a handful of goals, including a stepped-up research effort on the acidification of the coast’s waters and its impact on crustaceans. Maine lawmakers have already introduced legislation for limits on industrial and agricultural runoff, which contribute to coastal water acidification.
05 Feb 2015:
Ultra-Efficient Solar Cells
Can Be Adapted for Rooftops, Research Finds
Extremely efficient solar cells similar to those used in space may soon be ready for installation on residential rooftops, according to a report
in Nature Communications
. Concentrated photovoltaic (CPV) systems, which use lenses and curved mirrors to focus sunlight onto small solar cells, produce energy much more efficiently than conventional solar panels — 40-percent efficiency compared to less than 20 percent for standard silicon systems. But they are typically the size of billboards and have to be positioned very accurately to track the sun throughout the day. Now researchers have overcome these obstacles by developing a CPV system that uses miniaturized gallium-arsenide photovoltaic cells, 3D-printed plastic lens arrays, and a moveable focusing mechanism. The new system is small and light enough to fit on a residential rooftop and should be inexpensive to produce, researchers say.
04 Feb 2015:
Plant-Like Sea Slug Can Steal
Genes From its Food, Researchers Report
The emerald green, leaf-shaped sea slug known as Elysia chlorotica
can live for months at a time by
photosynthesizing its own food, like a plant does, but until recently scientists did not understand how the slug acquired and maintained this rare ability. A recent report in the journal The Biological Bulletin
shows that the slug steals genes and chloroplasts
— the cellular machinery that converts sunlight into food — from algae that the slug eats. Genes lifted from the algae can maintain cholorplasts in the slug for up to nine months, the researchers say — much longer than the chloroplasts would last in the algae themselves. Moreover, the slug can pass on those stolen genes to its offspring. The process is a mechanism of rapid evolution, says one of the study's authors.
02 Feb 2015:
Many California Farms and
Orchards Idled By Drought, NASA Maps Show
In 2014 — the driest year ever recorded in California — farms and orchards in the state's Central Valley took a major hit
Status of CA farms in 2011 (left) and 2014 (right).
and many agricultural plots were left fallow, as shown in these maps based on NASA satellite data
. The maps depict the status of crop cultivation in California in August 2011 and August 2014. Brown pixels show farms and orchards that have been left fallow, or “idled,” since January 1 in each year. Green pixels show plots where at least one crop was grown during the year. The most recent year with average or above average precipitation across the state was 2011, and, as the map shows, relatively little agricultural land was left fallow that year. In 2014, a much higher proportion of farms and orchards were idle.
15 Jan 2015:
Underwater Kelp Forests Mapped
In New Citizen Science Project
grow along roughly 25 percent of the world’s coastlines and provide valuable habitat and nutrients for many types of aquatic life. Now, research by the “Floating Forests
” project is shedding light on how these underwater kelp forests are affected by climate change. The project is using NASA satellite data to observe changes in kelp forests over a period of more than four decades. The catch: No accurate way to automate the process exists, so the researchers rely on an international team of nearly 3,500 citizen scientists to mark the bright green kelp forests, which contrast with the deep blues of the ocean in the images.
06 Jan 2015:
Penguin Watch Projects Asks
Citizen Scientists to Monitor Birds' Habits
, a citizen science project launched by researchers from the University of Oxford in the U.K., is enlisting the
Group of Gentoo penguins
public's help in counting penguins in some 175,000 photos from locations across the Southern Hemisphere. Researchers are monitoring five penguin species — Gentoo, Chinstrap, Adelie, Rockhopper, and King penguins — and recording information on the number of adults, chicks, and eggs, as well as their winter behavior, breeding success, and travel habits. The project is especially useful for monitoring penguins' winter behavior, for example, because it's logistically difficult for the researchers to visit these locations in winter, they say
, and the images are far too numerous for researchers to view on their own. Understanding how the penguins live day-to-day should help shed light on how the penguins will respond to an increasingly volatile climate, the team says.
05 Jan 2015:
U.S. Cities Are Significantly
Brighter than German Cities, Scientists Say
German cities emit several times less light per capita than similarly sized American cities, according to new research
published in the journal Remote Sensing
Berlin, Germany, at night
Moreover, the differences in light emission become more dramatic as city size increases: Light per capita increases with city size in the U.S. but decreases in Germany. Factors such as the type of lamps used and architectural elements like the width of the streets and the amount of trees are likely behind the differences, the researchers say. Energy-efficient LED street lighting
is currently being installed in many cities worldwide, and the researchers expect this to change the nighttime environment in many ways — for example, by reducing the amount of light that shines upward. The study also found that, in major cities in developing countries, the brightest light sources were typically airports or harbors, whereas the brightest areas in large European cities are often stadiums and city centers.