12 Jul 2013:
Europe’s Offshore Wind Sector
Is Growing, But Troubles Lie Ahead
European nations installed a record number of offshore wind turbines
during the first half of 2013, adding more than twice the capacity installed during the same period in 2012, according to the European Wind Energy Association (EWEA), an industry group. A total of 277 new turbines in seven wind farms were fully connected to the grid during the six-month period, adding 1,045 megawatts of capacity, with another 130 turbines installed but awaiting connection, the group says in a new report
. Although the new turbines bumped Europe’s total offshore wind energy capacity to 6,040 megawatts, officials say the sector’s growth is already slowing as a result of regulatory uncertainty in key countries. While European nations such as Germany and the UK have relied on large-scale wind projects to achieve renewable energy targets by 2020, the lack of a binding target for 2030 will cause growth to stall, said Justin Wilkes, EWEA’s policy director. “Financing of new projects has slowed down with only one project reaching financial close so far this year,” he said.
11 Jul 2013:
‘Peak Oil’ Concerns Overstated
As Demand Will Fall, Study Predicts
Researchers say concerns that humanity will inevitably reach a moment of “peak oil,” which would be followed by a crippling decline in supplies, are unwarranted
because global demand for oil is approaching its own peak
. Writing in the journal Environmental Science & Technology
, researchers from Stanford University and the University of California-Santa Cruz (UCSC) say that dire projections of peak oil mistakenly assume that an increasingly wealthy planet will continue to rely heavily on oil. On the contrary, they say, the link between economic growth and oil is breaking down as a result of increased energy efficiency, lower prices for alternative fuel sources, urbanization, and limits on consumption by the wealthy. While the researchers project surging global demand for airline travel and various forms of freight transportation, there will be less reliance on oil, with conventional oil demand declining after 2035.
10 Jul 2013:
Massive Iceberg Calves
Off Antarctica’s Pine Island Glacier
A massive chunk of Antarctica’s fastest-moving ice stream, the Pine Island Glacier, dropped into the Amundsen Sea this week
, nearly two years after
Click to enlarge
Alfred Wegener Institute/German Space Agency
Pine Island Glacier, 2011-2013
scientists first observed a crack in the glacier tongue. German scientists, who have been tracking the progress of the ice mass since NASA satellites first observed the crack in 2011, say the calved iceberg measured 720 square kilometers (278 square miles). There is no conclusive proof that climate change triggered the ice break, said Angelika Humbert, an ice researcher at the Alfred Wegener Institute. But shifting wind patterns around Antarctica are bringing warmer waters to the surface of the Southern Ocean in West Antarctica, which is hastening the thinning of some glaciers. Humbert said those warmer waters are causing the Pine Island Glacier to flow more rapidly into the Amundsen Sea.
09 Jul 2013:
Coal Emissions in China Slash
5.5 Years off Life Expectancy, Study Says
The life expectancy of people living in northern China is 5 ½ years less than in southern China
as a result of the north’s notoriously bad air pollution, largely due to the burning of coal, according to a new study. In an analysis
of air quality recordings from 90 Chinese cities from 1981 to 2000 and mortality data from the 1990s, a team of researchers estimated that high air pollution will cost the roughly 500 million people living north of the Huai River a combined 2.5 billion years of life expectancy compared with people living in the south. Writing in the Proceedings of the National Academy of Sciences
, the researchers say increased mortality, attributable to cardiorespiratory illness
, is the unintended consequence of a Chinese policy that from 1950 to 1980 provided free coal for boilers in cities north of the Huai, but not for those living in the south.
08 Jul 2013:
Crowdsourcing Project Targets
Open-Source Tool for Ocean Research
A team of marine researchers is developing a blueprint for an inexpensive tool to collect oceanographic data, a venture they hope will make ocean science more accessible
to other scientists, educators, and marine enthusiasts. Using an open-access model
, the researchers hope to build their own CTD, a widely used oceanographic instrument that collects information on ocean temperature, depth, salinity, and density. While CTDs are vital to marine research, the technology can be prohibitively expensive for some “citizen scientists,” with costs running $5,000 to $25,000 per instrument. Traditional CTDs are small, cylindrical instruments that are dropped from boats and relay data back to shipboard computers. Using a crowdsourcing website, organizers of the so-called OpenCTD project are raising funds to design a CTD capable of collecting ocean data down to 200 meters at a cost of about $200.
05 Jul 2013:
Largest Offshore Wind Farm
Opened in North Sea Off British Coast
British Prime Minister David Cameron has inaugurated the world’s largest offshore wind farm
, a 630-megawatt project capable of producing enough electricity to power 500,000 homes. The $2.3 billion project — located 12 miles offshore in the North Sea, east of London — is being operated by an international consortium that includes China’s Dong Energy, German’s E.ON, and Abu Dhabi’s Masdar. The so-called London Array
project, which contains 175 turbines, began producing energy in April but was officially inaugurated yesterday by Cameron. The project’s opening solidifies the UK’s position as a global leader in offshore wind energy. The country currently produces 3 gigawatts of power from wind energy and by 2020 aims to develop 18 gigawatts, much of it from offshore wind power installations.
03 Jul 2013:
Flexible Glass Solar Cells
Could Boost Effectiveness of Solar Shingles
U.S. researchers have developed a solar shingle made of flexible glass that could emerge as an alternative to conventional roof shingles and drive down the costs of
Corning’s Willow Glass
rooftop solar energy systems. Unlike conventional solar panels, which are bulky and breakable, the new solar cell built by the National Renewable Energy Laboratory is durable enough to last for decades, according to MIT’s Technology Review
. While typical panels must be mounted on top of asphalt shingles, the glass solar shingles can be nailed directly onto a roof instead of conventional shingles. The cells are made of a pliable material called Willow Glass, which was developed by Corning, the company that also makes the so-called Gorilla glass for iPhone screens. According to researchers, the glass can also utilize cadmium telluride — which can compete on a cost basis with more widely used silicon solar cells — as the solar cell material.
02 Jul 2013:
Drought Tolerance in Plants
Boosted by New Synthetic Chemical
Scientists have identified a chemical that helps plants better tolerate drought conditions
, a discovery they say could help boost crop production as extreme weather
Click to enlarge
Cutler Lab/UC Riverside
Soybean plant, right, treated with quinabactin
conditions become more common. After testing thousands of different molecules, researchers at the University of California, Riverside found and named a chemical, quinabactin, that caused the pores, or stomata, in Arabidopsis plants to close firmly, thus preventing water loss. The action is similar to the way a naturally occurring stress hormone, known as abscisic acid (ABA), performs in drought-tolerant plant varieties. While it was previously known that ABA triggers the closing of stomata pores during dry periods, the hormone is far too expensive to apply in agricultural fields, scientists say. Writing in the Proceedings of the National Academy of Sciences
, the researchers report that the synthetic chemical mimics the effects of ABA but is much simpler chemically and cheaper to produce.
01 Jul 2013:
Climate Change Driving
More Active El Niño Cycles, Study Says
A new analysis of tree-ring data indicates that the climate cycle known as the El Niño – Southern Oscillation (ENSO) has been more active during the latter part of the 20th century than at any other time during the past seven centuries
, suggesting that global warming is affecting this climate phenomenon. Using data from 2,222 tree-ring chronologies from the tropics and mid-latitudes in both the northern and southern Hemispheres, a team of scientists determined that ENSO-related behavior in the late 20th century was far greater than the natural variability reflected in data going back to 1300. A naturally occurring climate cycle, ENSO is characterized by warmer ocean temperatures off the west coast of South America, a phenomenon that can cause major droughts, floods, and extreme weather across the Pacific. According to Jinbao Li, a scientist at the University of Hawaii and lead author of the study published in the journal Nature Climate Change
, greenhouse gases are altering the planet’s radiation balance and thus intensifying ENSO cycles.
28 Jun 2013:
Global Biodiversity Maps
Show Species Health Down to Local Level
U.S. researchers have published a series of data-rich maps that identify the world’s conservation priority
Density of biodiversity, South America
hotspots with a level of detail they say is 100 times finer than previous assessments
. Using the latest data on more than 21,000 species of mammals, amphibians, and birds, the maps produced by North Carolina State University researchers provide a snapshot of biodiversity health at a 10-kilometer-by-10-kilometer scale, comparable to the geographic scale at which critical conservation decisions are made. The color-coded maps reveal patterns of biodiversity for the different types of species
. Researchers hope the information will help policymakers make best use of scarce conservation resources to protect the world’s most vulnerable species. The paper was published in the Proceedings of the National Academy of Sciences
27 Jun 2013:
New Bird Species Identified
In Crowded Outskirts of Phnom Penh
A team of scientists in Cambodia has identified a new species of lowland tailorbird
recently captured in the densely populated outskirts of Phnom Penh. Originally
An adult male Cambodia tailorbird
caught and photographed in 2009 during a routine sampling for avian influenza, the small wren-sized bird was initially misidentified as a known type of tailorbird until the photographs caught the attention of scientist Simon Mahood of the Wildlife Conservation Society. Following genetic analysis of other individuals collected in the region, scientists confirmed that the bird — which has white cheeks, a rich cinnamon-colored crown, and distinct vocal characters — was indeed a new species. According to an article co-authored by Mahood in Forktail
, a journal of the Oriental Bird Club, the so-called Cambodia tailorbird (Orthotomus chaktomuk
) is known to exist only in a dense, lowland scrub ecosystem that is declining in size and quality.
26 Jun 2013:
Exposure to Lead Costs
Developing Nations $1 Trillion Annually
The exposure of children to toxic lead, and the subsequent declines in IQ and earning potential, costs the developing world nearly $1 trillion annually
, according to a new report. Based on the average lead levels in children under the age of 5, researchers from New York University found that Africa suffers the greatest costs from lead exposure, losing an estimated $137.7 billion annually, or about 4 percent of its gross domestic product (GDP). In Latin America, the costs are about $142.3 billion, the study found, while in Asian nations the costs are about $699.9 billion. By comparison, the annual costs in the U.S. and Europe, where exposure to lead has decreased significantly in recent decades, are about $50 billion and $55 billion, respectively. The report said lead consumption has increased worldwide
since the early 1970s, largely because of rising demand for lead batteries. The study was published in Environmental Health Perspectives
25 Jun 2013:
President Obama Unveils
Sweeping U.S. Plan To Tackle Climate Change
President Obama today unveiled a long-awaited national strategy to tackle climate change
, a sweeping plan that will include cutting carbon emissions at power plants, protecting the coastline from rising seas, and a
greater U.S. role in global climate talks. Calling the need to address climate change a “moral obligation,” Obama asked the U.S. Environmental Protection Agency to develop strict new standards on carbon pollution from existing power plants
, the largest source of emissions, by June 2014, and complete standards for new plants by October. He also committed $7 billion for climate mitigation and adaptation projects, and $8 billion in incentives for energy efficiency and other innovations, including carbon capture technologies. Overall, the president’s strategy aims to cut U.S. carbon emissions by 17 percent from 2005 levels by 2020.
24 Jun 2013:
Houston to Buy Half of its
Electricity From Renewable Sources
The city of Houston has agreed to purchase half its electricity from renewable energy sources
, a step that makes the Texas city the nation’s largest municipal buyer of green energy. In a contract signed with Reliant Energy, Houston committed to buying more than 140 megawatts of renewable power from July 1, 2013 through June 30, 2015, locking in nearly 623,000 megawatts of clean power annually. According to city officials, the government committed $2 million — less than 1 cent per kilowatt-hour — through the purchase of renewable energy credits that will be used to fund alternative energy projects. “Houston is already known as the energy capital of the world, but we are committed to becoming the alternative energy capital of the world as well,” Mayor Annise Parker said in a statement
. In addition to investing in wind energy, the city touted major solar projects at municipal sites and efforts to streamline its solar power-permitting process.
21 Jun 2013:
Illegal Fires in Sumatra
Send Dangerous Pollution to Singapore
Billowing smoke from illegal fires on the Indonesian island of Sumatra has engulfed Singapore this week, pushing air pollution to record levels
consecutive days. The smoke, which is captured in a new NASA satellite image
, has created an acrid blanket of smog across the region and historic levels of air pollution. According to government officials, Singapore's air pollution index reached 401 on Friday, a level considered hazardous for breathing. Before this week, the previous high was 226. The smoke has been blowing east toward southern Malaysia and Singapore
from Sumatra, where farmers set illegal fires to clear land for new crops during the mid-year dry season. The fires are yet another sign of the large-scale deforestation taking place on Sumatra.
20 Jun 2013:
Global Reports Underline
Threats to Planet’s Bird Species
New global research underlines the rising threats facing the world’s bird species, with three reports providing evidence that climate change, overfishing, and unsustainable agriculture are taking a heavy toll on
Puffins along the Maine coast.
avian populations worldwide. The U.S. Fish and Wildlife Service (FWS) reports that numbers of some migratory bird populations in Maine — including Arctic terns and puffins — have plummeted in recent years
because their food supplies are disappearing as a result of commercial fishing and the shifting of fish to cooler waters, which is making it more difficult for some birds to feed their young. In a separate study, scientists predict that rising sea levels will devastate habitat for some migratory shore birds
in the coming decades. Higher sea levels, the study predicts, will flood 23 percent to 40 percent of the intertidal habitats for several shorebird species, triggering population declines of as much as 70 percent. Overall, one in eight bird species globally is at risk of extinction
, according to a new report by BirdLife International
19 Jun 2013:
Study Maps Likely Wildlife
Migration Corridors as Climate Warms
The southeastern U.S., eastern Canada, and the Amazon Basin could become three of the more heavily used wildlife thoroughfares as species are forced to relocate
Click to enlarge
University of Washington
Wildlife corridors in the southeastern U.S.
in response to warming temperatures in the future, according to a new study
. In an analysis of how nearly 3,000 species of mammals, birds, and amphibians in the Western Hemisphere will have to travel to find more hospitable climes — and the human-built barriers, such as cities and agricultural land, that could stand in their way — scientists from the University of Washington found that some regions will see far more animal movement than others. In the southeastern U.S., the Appalachian Mountains are expected to provide a conduit for species movement, as are northern regions of the eastern U.S., including the area around the Great Lakes, the study found. According to the study, published in Ecology Letters
, the findings can help guide conservation and land use planning along these critical migration corridors.
Interview: Coal-Fired Plants and the
Struggle for Environmental Justice
As the NAACP’s Environmental and Climate Justice Director, Jacqueline Patterson often finds her work questioned by constituents of the venerable civil rights
organization. “Some of the communities I work in were like, ‘Well, we’re dealing with double digit unemployment and people dying of AIDS, people being racially profiled, high murder rates. How is melting ice caps and polar bear extinction going to become a priority for us?’” In an interview with Yale Environment 360
, Patterson discusses how she answers that thorny question and outlines the reasons behind the NAACP’s campaign to shut down coal-fired plants, which disproportionately affect minority communities. She also talks about the often-difficult relationship between environmental justice organizations and major U.S. green groups. “We need more joint strategizing on how we can collaborate more effectively," she says. Read the interview
18 Jun 2013:
Low-Cost Deals and Incentives
Drive Record Sales of Electric Cars
After years of sluggish sales, the market for electric vehicles has surged in recent months in response to an escalating price war among automakers
that has helped reduce the high up-front costs that have slowed the emerging EV sector. Since Nissan reduced the price of its electric Leaf by $6,400 to $19,000 earlier this year — a move that tripled sales of the car compared with the same time period last year — competitors such as Chevy, Fiat, Mitsubishi, Honda, and Toyota have responded with similar low-cost deals and buyer incentives, Time
magazine reports. Within days of cutting the lease price for its Fit EV from $389 per month to $259 per month, Honda dealerships in California sold every model of the EV, forcing the automaker to apologize to customers who were then placed on a waiting list. But while the price war is driving EV sales and boosting consumer interest in the emerging green technologies, it is unclear whether it will be good for business in the long term. Chrysler, which owns Fiat, reported earlier this year
that the company loses $10,000 for each Fiat 500e EV it sells.
17 Jun 2013:
Changes in Jet Stream Triggered
Record Greenland Melt in 2012, Study Says
An unusual shift in the jet stream triggered the historic level of surface ice melt
that occurred across Greenland last summer, a new study says. Using satellite data and a computer model simulation, scientists from the University of Sheffield found that a high-pressure system developed in the mid-troposphere over Greenland for much of the summer, pushing warm southerly winds over the western edge of the ice sheet and creating a “heat dome” over Greenland. According to the study, published in the International Journal of Climatology
, this unprecedented event caused record melting across virtually the entire ice sheet, including on Summit Station, Greenland’s highest peak. Ocean temperatures and Arctic sea ice retreat, meanwhile, played a minimal part in the record surface ice melt, the scientists reported. The study predicted that the record ice melt of 2012 is not likely to be “climatically representative of future ‘average’ summers” during the coming century.
14 Jun 2013:
Nicaragua Approves New Canal
Linking Atlantic and Pacific Oceans
Nicaragua has approved plans to build a $40 billion cross-country canal
linking the Atlantic and Pacific oceans, a project that would rival the Panama Canal but is raising major concerns about impacts on regional
water supplies and the environment. Lawmakers yesterday granted Hong-Kong-based HK Nicaragua Canal Development Investment Co. a 50-year concession to study, and possibly construct, a 180-mile canal that advocates say would better accommodate the massive cargo ships and supertankers needed to handle the increased trade between Asia and the Americas. Major questions remain, however, about whether the canal will ever be built. Environmental advocates warn that water needed to operate the massive infrastructure project would deplete the region’s freshwater supplies.
13 Jun 2013:
Population Could Be 11 Billion
By End of the Century, UN Report Says
United Nations report
projects that the world population could reach nearly 11 billion by 2100
, about 8 percent more than predicted just two years ago. The projected increase largely stems from the fact that the fertility rate in Africa has declined more slowly than expected, with demographers now forecasting that the number of people on the continent could nearly quadruple this century, from from about 1.1 billion today to about 4.2 billion. “The fertility decline in Africa has slowed down or stalled to a larger extent than we previously predicted, and as a result the African population will go up,” said Adrian Raftery, a professor of statistics and sociology at the University of Washington, who helped develop the statistical method used in the report. The total world population passed 7 billion in 2011. According to the new report, 8 of the top 10 increases in national populations by 2100 will occur in Africa, led by Nigeria, where the number of people is expected to jump from 184 million to 914 million.
12 Jun 2013:
Bird-Mimicking Mobile Apps
Harmful to Species, UK Groups Say
Wildlife officials in the UK are urging people not to use mobile phone apps that mimic bird songs in nature reserves, warning that the devices can harm some sensitive species
, particularly during breeding season.
Icon for Chirp! app
The increasingly popular apps, which use recordings of bird calls to lure the birds closer for photographs or better viewing, can distract birds from critical tasks, such as feeding their young, according to the Royal Society for the Protection of Birds. The Dorset Wildlife Trust (DWT), a conservation group that oversees 42 reserves, is discouraging the use of the mobile apps at its reserves
, calling it an intentional disturbance of sensitive species such as the Nightjar, a nocturnal bird that has experienced a recent recovery in the area. “I’m sure visitors would be devastated if they realized the possible disturbance they were causing to wildlife,” said Chris Thain, a manager at DWT’s Brownsea Island reserve.
11 Jun 2013:
Growing Number of Pests
Developing Resistance to GM Crops
An increasing number of pest species are developing resistance to crops genetically engineered to be toxic to insects
, according to new research. In an analysis of 77 studies conducted in eight countries, a team of U.S. and French scientists found that five of 13 major pest species had become resistant to so-called Bt cotton or corn plants, which are genetically modified to exude a bacterium, Bacillus thuringiensis
, that is toxic to insects. While researchers say all insects inevitably adapt to threats such as pesticides, the study found that farmers who planted non-Bt crops in nearby “refuges” were more likely to slow that resistance. “Either take more stringent measures to delay resistance, such as requiring larger refuges, or this pest will probably evolve resistance quickly,” said Bruce Tabashnik, a professor at the University of Arizona and lead author of the study published in the journal Nature Biotechnology
. The total land area planted annually with Bt crops has increased from 1.1 million hectares in 1996 to more than 66 million hectares in 2011.
Interview: How Detergent Became
A Catalyst for Green Innovation
Adam Lowry is the co-founder and “chief greenskeeper” of Method
, a small but rapidly growing company that has been a leader in the field of manufacturing
environmentally friendly cleaning and personal care products. Indeed, it was Method that pioneered the use of concentrated laundry detergent, an environmentally beneficial innovation that has been embraced by all the giant brands. Lowry and his partner, Eric Ryan, founded Method in 2001 and today the firm has more than $100 million in revenues and sells its products in retailers like Target and Whole Foods. In an interview with Yale Environment 360
, Lowry discusses how his company has managed to profit from sustainability, why major corporations have been slow to embrace environmental innovations, and how plastic trash in the Pacific Ocean made its way into Method’s bottles of hand soap. Early on, says Lowry, “we recognized that our little business had the ability to catalyze much bigger change.” Read the interview
10 Jun 2013:
Carbon Emissions Increased
1.4 Percent in 2012, IEA Reports
Global energy-related carbon dioxide emissions increased by 1.4 percent in 2012
, a pace that could lead to a temperature increase of as much as 5.3 degrees C (9 degrees F) over pre-industrial times, according to the International Energy Agency’s (IEA) latest World Energy Outlook
. Despite significant improvements in some regions, including the U.S. and Europe, a record 31.6 gigatons of carbon dioxide were emitted worldwide during the year, including a 5.8-percent increase in Japan
, where more fossil fuels were burned to compensate for reductions in nuclear power. While the rate of emissions growth in China was dramatically lower than in recent years, it still emitted 3.8 percent more carbon dioxide in 2012 than in 2011. In its report, the IEA encouraged four strategies to prevent what it says will be a catastrophic temperature increase: improved energy efficiency in buildings, industry, and transportation; a reduction in construction and use of coal-fired plants; reduced methane emissions; and a partial phaseout of fossil fuel consumption subsidies.
07 Jun 2013:
New Map of Antarctica Provides
Clearest Glimpse of Subglacial Continent
British scientists have unveiled the most detailed topographical map available yet of Antarctica
, a vast dataset that provides a penetrating 3-D view of the
Click to enlarge
NASA Goddard Space Flight Center
Antarctica's subglacial terrain
frozen continent down to the bedrock level and could offer insights into how it will respond to climate change. Based on millions of measurements collected over decades, the British Antarctic Survey
’s Bedmap2 project illustrates the continent with a level of clarity not previously available, including a vivid look at the mountain landscapes buried in ice and valleys that run deeper than had been known. The scientists say better understanding the landscape will help them predict the behavior of Antarctica’s ice sheet in future decades and the extent to which melting could increase sea levels. The map was based on data collected by satellites, land-based surveys, and ice-penetrating measurements of the subglacial bedrock
06 Jun 2013:
Carbon Emissions in Brazil
Dropped 39% from 2005 to 2010, Report Says
Greenhouse gas emissions in Brazil fell by nearly 39 percent from 2005 to 2010
, largely because of reductions in the amount of forest loss, according to a new government report. Overall, Brazil emitted the equivalent of 1.25 billion tons of carbon dioxide in 2010, which was more than 10 percent lower than 1990 levels. About 76 percent of the reductions were the product of a dramatic decline in deforestation across the Amazon and surrounding savannahs, according to the government inventory. That decline was driven by the country’s conservation policies, including stricter enforcement of land use laws, expansion of protected regions, and stronger local incentives to achieve environmental goals. For the first time, agriculture accounts for the largest share of emissions. In fact, rising emissions from agriculture and the energy sector threaten to offset improvements achieved through reduced forest loss, experts warn.
05 Jun 2013:
First Amphibian Declared Extinct
‘Rediscovered’ in Israel’s Hula Valley
A team of scientists says it has “rediscovered
” in northern Israel the first amphibian declared extinct by the International Union for Conservation of Nature (IUCN), a species of frog that turns out to be the only
surviving member of an extinct genus of frogs. First discovered in Israel’s Hula Valley in the 1940s, the Hula painted frog was presumed gone when Hula Lake dried up in the late 1950s, and it was declared extinct in 1996. But since an individual frog was discovered during a patrol in Hula Nature Reserve in 2011, an additional 10 specimens have been found, according to a study published in the journal Nature Communications
. And while the frog had originally been categorized as a member of the Discoglossus
group of painted frogs, which are found across northern and western Africa, genetic analysis has revealed that the Hula frog is more closely related to a genus of frogs, Latonia
, that were common across Europe during prehistoric periods but considered extinct for a million years. “In other words,” the study says, “the Hula painted frog is a living fossil.”
04 Jun 2013:
Nanofilter System Can Deliver
Clean Water to Rural Families for $2.50
Indian scientists have developed a filter system they say can provide clean water to rural families for less than $2.50 per year
and help reduce incidences of diarrhea that cause tens of thousands of deaths in the developing world annually. Writing in the Proceedings of the National Academy of Sciences
, researchers from the Indian Institute of Technology Madras (IITM) describe the filter, which contains a composite of nanoparticles, held within a sieve, that emit a stream of silver ions that eradicate water-based microbes. In producing the filter, the team used a material called aluminium oxyhydroxide-chitosan, which, because of its structure and the diameter of the silver nanoparticles, is optimal for releasing the silver ions at temperatures of between five to 35 degrees C. In addition, the material is widely available, and environmentally friendly, and it keeps concentrations of the silver ions below safe drinking water standards, lead author Thalappil Pradeep told ScieDev.Net
. So far, the scientists have installed the filters in water treatment plants in West Bengal, but are now seeking a company to produce the devices for widespread use.