Science & Technology
07 Jul 2015:
Self-Driving Taxis Could Spur
Major Cuts in Carbon Emissions, Study Says
By 2030, self-driving electric taxis could cut greenhouse gas emissions from car travel in the U.S. by up to 94 percent, if they were
Prototype of a small, self-driving electric taxi
to replace conventional personal vehicles, according to
an analysis published in the journal Nature Climate Change
. Autonomous taxis are projected to cut carbon emissions primarily through a process known as "right-sizing," or deploying a car that is specifically tailored to match occupancy needs of each particular trip. Right-sizing is cost-effective for both the fleet owner and for passengers, the researchers say, and companies and research groups are currently exploring how to efficiently manufacture small one- and two-seat vehicles. Optimal routing, smoother acceleration and braking, and a cleaner electric grid in 2030 would also contribute to lower carbon emissions. Autonomous taxis are projected to reduce emissions by 63 to 82 percent compared to hybrid cars likely to be on the road in 2030, and by 94 percent over a 2014 gasoline-powered model, the study found.
29 Jun 2015:
Rain Harvesting Could Provide
Major Economic Benefit in India, Study Finds
Collecting precipitation in rain barrels could result in significant savings for many people in India, according to
an analysis of
precipitation data collected by a NASA satellite. Estimates showed that harvested rain could provide at least 20 percent of average indoor water demand, or entirely irrigate a household vegetable garden. The savings associated with a vegetable garden could be between 2,500 and 4,500 rupees per year (39 to 71 U.S. dollars) — an amount equivalent to half a year’s rent in an average 1-bedroom apartment in an Indian city. In a country where the distribution of potable water is a challenge, rainwater is an untapped resource that could provide significant benefits, the researchers write in the Urban Water Journal
Photo Gallery: Scenes From
The Golden Age of Animal Tracking
Scientists are following the lives of animals in more detail than ever before, thanks to a new generation of tracking and tagging devices. From beluga whales that collect data on the Arctic Ocean to ducks that help track the spread of avian flu, data gathered by and about animals is being used to identify conservation hotspots, reduce human-animal conflicts, and monitor the health of the planet. In an e360
gallery, we look at some intriguing projects that have used state-of-the-art animal tracking and monitoring technology.
View the gallery.
24 Jun 2015:
Global Fine Particle Pollution
On the Rise Despite Regional Improvements
Air pollution from fine particulate matter has decreased significantly in North America and western Europe over the
Fine particulate air pollution levels, 2010-2012
past two decades, but increases in East and South Asia have more than made up for those improvements, as these maps based on NASA satellite data
show. The U.S. and Europe have many PM 2.5 ground-based monitoring stations, but large swaths of Africa, Asia, Central America, and South America are unmonitored. To fill these gaps, researchers have been developing techniques that use satellite data to better estimate PM 2.5 levels around the globe. They've found that, as a whole, the worsening PM 2.5 pollution in Asia outweighed improvements in North America and Europe, and global PM 2.5 concentrations have increased by 2.1 percent per year since 1998.
22 Jun 2015:
Researchers Look to Design of
Owl Wings to Make Quieter Wind Turbines
A new type of coating for wind turbines inspired by the shape of owl wings may dramatically cut noise associated with onshore
Australian masked owl in flight
wind farms, according to
research from the University of Cambridge. The scientists found that an owl's flight feathers have a microscopic down-like covering and numerous other intricate design details that smooth the passage of air over the wing, scattering sound as the owl flies. To replicate the structure, the researchers looked at designing a covering that would scatter the sound generated by a turbine blade in the same way. Early tests of their prototype material, a 3D-printed plastic coating, demonstrated that it could significantly quiet wind turbines without any appreciable impact on aerodynamics. Since wind turbines are heavily braked in order to minimize noise, the new technology could mean that turbines could spin at much higher speeds, producing more energy while making less noise.
19 Jun 2015:
Jet Contrails Can Affect
Air Temperature in Some Areas, Study Shows
Jet contrails can mimic the weather impact of clouds and significantly affect daytime and nighttime air temperature
Persistent jet contrails
swings — by up to 6 degrees Fahrenheit in some locales — researchers from Penn State have shown
. Data from the three days following September 11, 2001, when air travel was highly restricted, had shown that jet contrails — thin clouds composed of ice crystals condensed from an aircraft's exhaust — likely had an effect on air temperatures. To study the issue over a longer time period, the researchers looked at daily temperature data from locations in the South and Midwest that often see persistent jet contrails. They found that contrails, like clouds, depress the difference between daytime and nighttime temperatures, typically lowering daytime highs and raising nighttime lows. In the South, this amounted to a 6 degree F reduction in daily temperature range, and in the Midwest, roughly a 5 degree F reduction.
17 Jun 2015:
Harnessing Evaporation Could
Yield More Power than Wind, Study Shows
Using the energy produced by evaporating water, researchers at Columbia University have shown
that they can
A miniature car driven by evaporation.
power a small toy car and a flashing light — the first step, they say, in harnessing an immense energy source that could rival power production from wind and waves. The devices they built use bacterial spores that can absorb humidity and, in doing so, expand and contract with enough force to push and pull pistons and drive a rotary engine. The spores pack more energy, pound for pound, than other materials used in engineering for moving objects, said researcher Ozgur Sahin, who co-authored the study published in Nature Communication
. When evaporation energy is scaled up, he says, it could one day produce electricity from giant floating power generators that sit on bays or reservoirs or rotating machines like wind turbines that sit above water.
Interview: Is Cloning Mammoths
Science Fiction or Conservation?
Biologist Beth Shapiro has published a new book, How to Clone a Mammoth
, that looks at the many
questions — both technical and ethical — surrounding any attempt to revive extinct species. In a Yale Environment 360
interview, Shapiro, associate director of the Paleogenomics Institute at the University of California at Santa Cruz, explains why she believes new gene-editing technology could benefit critical ecosystems and living species that are now endangered. “We are in the midst of an extinction crisis,” she says. “Why would we not use whatever technologies are available to us, assuming we can go about doing it in a reasonable and ethical way?”
Read the interview.
16 Jun 2015:
Human Data Can Improve
Ecosystem Service Models, Study Says
Protected forests in Brazil, Costa Rica, Indonesia, and Thailand have prevented the release of more than 1 billion tons
Aerial view of the Amazon rainforest in Brazil.
of carbon dioxide into the atmosphere, an ecosystem service worth at least $5 billion, Georgia State University economists found
. Their conclusion about the monetary benefit of those forest protections is based on a new method they derived for valuing services such as carbon capture, conservation, and improvements in air and water quality. Instead of relying on modeling alone, the new method uses interviews and on-the-ground data to see how conservation programs affect human behavior and impact ecosystems. By combining the two types of information — environmental models and social science data — public officials can gain more realistic insights into how a particular policy might affect the environment and the people who interact with it, the researchers write in the Proceedings of the National Academy of Sciences
15 Jun 2015:
Biodiversity Limits Parasites
In Humans, Wildlife, and Plants, Study Says
High biodiversity generally limits outbreaks of disease among humans and wildlife, University of South Florida researchers write in the Proceedings of the National Academy of Sciences
. The new research is the first to quantitatively support the controversial "dilution effect hypothesis," which warns that human-driven biodiversity losses can exacerbate parasite outbreaks. Much of the debate surrounding this idea concerns whether it applies generally or only to a few select parasites. After reviewing more than 200 published scientific assessments, the USF team found "overwhelming" evidence that the dilution effect applies broadly to many parasitic species in humans and wildlife. They also found that plant biodiversity reduces the abundance of herbivore pests. The results have implications for public health efforts, the researchers say, and make a case for better management of forests, croplands, and other ecosystems.
10 Jun 2015:
Jet Fuel from Sugarcane
Cuts Aviation Carbon Emissions, Study Says
Converting sugarcane to jet fuel can reduce greenhouse gas emissions from air travel by up to 80 percent and the process could be scaled up to produce commercially viable amounts
of fuel, say researchers from the University of California, Berkeley. The new technique they developed, which is described in the Proceedings of the National Academy of Sciences
, relies on complex chemical reactions involving sugars and waste biomass from sugarcane. That crop, unlike the sugar beet, can be grown on marginal lands so it does not displace food production — a major concern that has tempered enthusiasm for biofuels in general. Jet fuel, which is responsible for roughly 2 percent of all carbon emissions, has been difficult to synthesize from biomass because of its stringent quality requirements. Biofuels were approved for commercial aviation as recently as 2011, and researchers have been seeking a viable production method for nearly a decade.
08 Jun 2015:
Reforming Mobile Phone Industry
Helps Profits and Environment, Study Says
Mobile phone manufacturers and the environment would both benefit from producing less-complex phones that
Millions of unused phones are discarded each year.
use "the cloud" — a network of remote servers connected to the Internet — to carry out power-intensive tasks, researchers say
. The current business model encourages consumers to upgrade devices frequently with little incentive to recycle them, researchers write in the International Journal of Life Cycle Assessment
. There are roughly 85 million unused phones in the U.K. alone, the researchers note, and replacing the gold they contain — not to mention copper, silver, and other rare metals
— would cost nearly $170 million and release an equivalent of 84,000 tons of CO2. Moving to a "cloud-based" system where heavy computing is done on remote servers would allow manufacturers to produce less-complex phones that are designed to last longer and require fewer valuable metals, the analysis found.
02 Jun 2015:
Pollution From Carbon Monoxide
Has Fallen Steadily Since 2000, Data Show
As these NASA satellite maps show
, carbon monoxide levels have decreased appreciably in much of the world since 2000, thanks to
Global carbon monoxide levels as of 2014
improved pollution controls on vehicles and factories and fewer forest fires. Carbon monoxide, which is produced whenever carbon-based fuels are burned, contributes to the formation of ozone, a pollutant that can have adverse health effects. A NASA satellite carrying a sensor called MOPITT — Measurements of Pollution in the Troposphere — measures carbon monoxide levels. Higher concentrations of CO are depicted on the map in orange and red and lower concentrations in yellow. NASA said that the decrease in CO levels from 2000 to 2014 was particularly noticeable in the northern hemisphere thanks to technological and regulatory innovations that have led to lower pollution levels from vehicles and industry. Carbon monoxide levels also have decreased in the southern hemisphere since 2000, due largely to a reduction in deforestation fires.
29 May 2015:
Ozone Benefits of Montreal
Protocol Already Widespread, Study Says
The planet's protective ozone layer is in far better shape today thanks to the United Nations' Montreal Protocol, which came
Ozone hole without the Montreal Protocol
into force in 1987 and restricted the use of ozone-depleting substances such as CFCs, according to a new study in Nature Communications
. The researchers used 3D atmospheric chemistry modeling to look at what might have happened to the ozone layer had the treaty not been implemented. The findings suggest that the Antarctic ozone hole would have grown by an additional 40 percent by 2013 and, had ozone-depleting substances continued to increase, the ozone layer would have become significantly thinner over other parts of the globe. A very large ozone hole over the Arctic would have occurred during the exceptionally cold Arctic winter of 2010-2011 — colder temperatures cause more loss — and smaller Arctic ozone holes would have become a regular occurrence.
Designed for the Future:
Practical Ideas for Sustainability
From packing materials made of mushrooms to buildings engineered to cool and power themselves, sustainable design can play a key role in helping people adapt to a changing planet. That’s a central message of the new book Designed for the Future
, in which more than 80 experts in sustainable design — architects, journalists, urban planners, and others — are asked to point to a specific project that gives them hope that a sustainable future is possible. Their selections vary widely, from communities that leave no carbon footprint to cutting-edge technological research programs. An e360
gallery highlights a few of the projects they say have inspired them.
View the gallery.
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.