23 Aug 2013:
Arsenic in Groundwater
May Affect 20 Million People in China
Nearly 20 million people in China are exposed to high levels of arsenic in the water they use for drinking and cooking, a new model based on geological and
hydrological data and well samples shows. The model predicts high arsenic concentrations
(10 micrograms per liter or greater) across more than 580,000 square kilometers, according to Chinese and Swiss researchers, who published their findings in Science
. Researchers had long known that some regions had high arsenic concentrations, but it would have taken several decades to test the millions of wells in China. The new prediction combined the most recent tests with data about the underlying geology, soil characteristics, and topography.
26 Jul 2013:
Parched New Mexico Reservoir
Reveals Effects of Prolonged Drought
A pair of satellite images released by NASA this week
shows the effects of a severe drought on New Mexico’s largest reservoir, where water levels are at their lowest
levels in four decades. Earlier this week, the U.S. Army Corps of Engineers estimated that Elephant Butte reservoir in southern New Mexico was holding about 65,057 acre-feet of water, only 3 percent of its capacity of 2.2 million acre-feet, largely as a result of prolonged drought conditions and unusually low spring snowmelt from nearby mountains. That represents the lowest water levels in the reservoir since 1972. From the mid-1980s to 2000 the reservoir was nearly filled to capacity, as illustrated in a 1994 satellite image, top, released by NASA. The reservoir, fed by the Rio Grande, provides water for about 90,000 acres of agricultural land and about half the city of El Paso, Tex.
15 Jul 2013:
Map Shows Possible Link
Between Warmer Springs and Large Fires
An interactive tool produced by the group Climate Central illustrates how rising temperatures and reduced snowpack in the western U.S. have corresponded with an increase in wildfires
in recent decades. Based on
federal wildfire data from 1970 to 2012, the graphic shows how large fires in some western states — including Arizona, Colorado, and Idaho — have doubled or even tripled in four decades, a period when the average spring and summer temperatures in 11 states increased by more than 1.5 degrees F. According to the Climate Central analysis, Arizona has experienced the highest average increase in spring temperatures, about 1 degree F, which has likely been a key factor in the steep increase in fires covering more than 1,000 acres. Another key factor has been the decrease in mountain snowpack. During several seasons, unusually low amounts of spring snow caused extended droughts that helped drive more big fires.
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.
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.
31 May 2013:
Getting More ‘Crop-per-Drop’
In World’s Driest Agricultural Regions
Improvements in irrigation in the world’s driest regions could significantly boost food production and water sustainability, according to a new study
. In an analysis of how water is used for 16 staple food crops worldwide, including in regions with similar climates, a team of researchers identified specific areas where major efficiency improvements can be made in the so-called “crop per drop” — or the amount of food produced per liter of water. According to their findings, published in the journal Environmental Research Letters
, about 40 percent of the available water in some dry regions is used to produce about 20 percent of the food calories. But in other regions with similar climate conditions, the productivity is much greater, said Kate A. Brauman, a researcher at the University of Minnesota’s Institute on the Environment. If these less-productive regions could improve their crop-per-drop productivity by even a modest amount, she said, “this would increase annual production on rain-fed croplands by enough to provide food for about 110 million people.”
24 May 2013:
Majority of Earth’s Population
Faces Water Shortages by Mid-Century
A conference of 500 of the world’s leading water scientists issued a stark declaration
at the end of a four-day meeting in Germany, warning that within two generations a majority of the people on the planet will face problems obtaining ample supplies of clean water. At the meeting, “Water in the Anthropocene,” the scientists said that the of over-pumping of underground aquifers, soaring populations, pollution, the over-use of fertilizers, and climate change are seriously threatening supplies of freshwater
around much of the globe. Continuing on the current path will mean that most of Earth’s population “will be living under the handicap of severe water pressure,” the scientists said, adding, “This handicap will be self-inflicted and is, we believe, entirely avoidable.” The conference proposed a wide range of solutions, including better study and monitoring of water supplies, basic reform in irrigation and agriculture, and innovation in the institutions that set national and global water policy.
17 Apr 2013:
Outdated Management, Drought
Threaten Colorado River, Report Says
Drought, mismanagement, and over-exploitation of its waters have made the Colorado River — the lifeblood of the arid Southwest and drinking water source for 36 million people — among the most vulnerable rivers in
the U.S., according to the group American Rivers. In its annual report on “America’s Most Endangered Rivers
,” the organization placed the 1,400-mile Colorado at the top of the list of threatened rivers, saying the iconic river “is so dammed, diverted, and drained that it dries to a trickle before reaching the sea.” Proposals to remove more than 300,000 acre-feet of new water from the river and its tributaries, coupled with a projected reduction in its flow of 10 to 30 percent because of global warming, will add further stress to the Colorado system
. According to the report, outdated water management systems also threaten the Flint River in Georgia, the San Saba River in Texas, and the Little Plover River in Wisconsin. In the U.S. Southeast, storage ponds for coal ash pose a threat to the Catawba River, a major source of drinking water for parts of North Carolina and South Carolina.
26 Mar 2013:
China’s Utility Giants
Vulnerable to Water Scarcity, Report Says
China’s five largest power utilities, which depend on water-intensive, coal-fired stations to generate electricity, are vulnerable to water supply disruptions because they are centered in the country’s water-scarce northern regions, a new report says. According to Bloomberg New Energy Finance
, the five power generators — Huaneng, Datang, Huadian, Guodian, and China Power Investment — operate hundreds of gigawatts of thermal plants in the industrial northeast, where water resources are increasingly strained. Eighty-five percent of China’s power-generating capacity is in water scarce regions, said Maxime Serrano Bardisa, one of the report’s coauthors. The report said that major technical and policy shifts will be required to avert serious disruptions, including the addition of systems that use less water, such as closed-cycle or air-cooled systems. Such improvements could cost the utilities $20 billion in retrofit costs, the report said.
18 Mar 2013:
New Chinese Premier
Vows To Tackle Pollution With ‘Iron Fist’
China’s new premier, Li Keqiang, has vowed aggressive government action
to curb the rampant pollution that has provoked growing public outrage, saying the country would phase out “backward production
Smog covers Beijing in January
facilities” that have contributed to dangerous health conditions in numerous regions. Speaking at his first press conference, Li said the government would set deadlines to address the public health controversy, exemplified by choking air pollution over Beijing that has kept air quality at dangerous levels
since the beginning of the year. Chronic air pollution problems in major metropolitan areas, coupled with a recent episode in which more than 12,000 rotting pig carcasses
were discovered in a river that provides Shanghai’s drinking water, have triggered growing public protest. While Li offered few specific solutions, he promised “vigorous” efforts to tackle pollution. “We need to face the situation and punish offenders with no mercy and enforce the law with an iron fist,” he said. “We shouldn’t pursue economic growth at the expense of the environment.”
13 Mar 2013:
New Desalination Process
Slashes Costs of Producing Fresh Water
Lockheed Martin, one of the world’s largest military contractors, has developed a process that company officials say significantly reduces the amount of energy needed to desalinate water
, an innovation that could help communities worldwide tackle the growing threat of water scarcity. According to the company, the new process uses ultra-thin carbon membranes with holes large enough to allow water to pass through, but small enough to block the salt molecules in seawater, Reuters reports. Because the membranes have holes as thin as a single atom, the process would require far less energy than existing desalination technologies, which rely on reverse osmosis, the company says. “It’s 500 times thinner than the best filter on the market today and a thousand times stronger,” said John Stetson, a Lockheed Martin engineer. “The energy that’s required and the pressure that’s required to filter salt is approximately 100 times less.” A 2011 study
found that desalination technology could be the cheapest approach to meeting the planet’s growing water needs.
08 Mar 2013:
Largest U.S. Dam Removal
Releases Huge Amount of Sediment
Scientists tracking the aftermath of the largest dam removal in U.S. history say the dismantling of a dam in northwestern Washington state has unleashed about 34 million cubic yards of sediment and debris
that built up
A plume of sediment at the mouth of the Elwha River.
for more than a century. While about one-third of the 210-foot Glines Canyon Dam on the Elwha River still stands, vast amounts of sediment are already flowing downstream, allowing University of Washington (UW) scientists a rare opportunity to track the discharges and study their ecological impacts. Scientists say it is unclear where much of the sediment will end up — or what the environmental consequences will be. In an ongoing study, they will use sophisticated technology to track particles in the water and monitor their accumulation on the ocean floor. Scientists say the sediment — enough to fill 3 million truckloads — could create murkier water conditions, threatening the reproduction of salmon and blocking light for marine life.
27 Feb 2013:
Oxfam Ranks Food Giants on
Sourcing and Environmental Policies
The group Oxfam has published an online scorecard assessing the agricultural sourcing of the world’s biggest food and beverage companies, rating them on factors that include water resource management, climate
awareness, and transparency. Using publicly available information, the “Behind the Brands
” campaign rates the 10 companies with the largest overall revenues — including Nestlé, PepsiCo, Unilever, Mars, and General Mills — on their awareness and responsiveness to these issues and supply chain management. According to Oxfam's analysis, Europe-based companies Nestlé and Unilever earned the highest scores overall, receiving good marks for water management and workers’ rights. Seven of the 10 companies received the lowest possible score for land management
. Associated British Foods, Kellogg’s, and General Mills received the lowest overall scores. Oxfam says the scoreboard will be updated regularly.
19 Feb 2013:
New Global Standard Aims
To Reduce Water Waste by Businesses
The UK-based Carbon Trust has introduced what it calls the first global standard on water management and reduction
in hopes of encouraging more sustainable water use by businesses. The new standard, created by members of the group along with four early-adopting companies, including Coca-Cola Enterprises, will require businesses to show that they are measuring their water use and reducing consumption on a year-to-year basis, Carbon Trust executive Tom Delay told BBC News
. “We look at the various water supply methods: mains, surface water abstraction, groundwater, and rainwater collection,” he said. The Carbon Trust, which already helps business and governments reduce energy use and carbon emissions, decided to expand into water issues since freshwater scarcity is closely linked with climate change. According to a 2009 report
, global freshwater demand will outpace currently available supplies by 40 percent by 2030. In a survey of 475 companies in the U.S., UK, China, and Brazil, the Carbon Trust found that just one out of seven businesses have set targets for water reduction and report their performances publicly.
13 Feb 2013:
Middle East Water Loss
Is Starkly Documented by NASA Satellites
A pair of gravity-measuring NASA satellites has documented a precipitous drop in freshwater supplies in the arid Middle East
over the past decade. NASA said that since 2003 parts of Turkey, Syria, Iraq, and Iran had lost 144 cubic kilometers of total stored freshwater, an amount roughly equivalent to the water in the Dead Sea. NASA researchers attributed 60 percent of the loss to increased pumping of groundwater from underground reservoirs. An additional 20 percent of the loss came from soil drying up and snowpack shrinking, while the remaining 20 percent came from loss of surface water in lakes and reservoirs, according to the NASA study, to be published Friday in the journal Water Resources Research.
A drought in 2007 exacerbated all of these trends, but even without the drought scientists said that the rapidly growing population in the heart of the Middle East was using too much water at a time of increasing concern over intensifying droughts caused by climate change. The GRACE satellites — short for Gravity Recovery and Climate Experiment — measure changes in gravity
, in this case caused by the falling of water reserves, which alters the earth’s mass.
Interview: What’s Damaging U.S.
Salt Marshes and Why It Matters
For centuries, salt marshes along the U.S. coast have been disappearing, with some experts estimating that 70 percent have been lost to development, rising seas,
and other threats. One factor scientists always thought marshes could withstand was nutrient enrichment, such as the flow of nitrogen and phosphorus from fertilizers and septic systems. But a nine-year study led by Marine Biological Laboratory scientist Linda Deegan shows that an over abundance of nutrients may be contributing to the demise of these salt marshes. In a Yale Environment 360
interview, Deegan describes the study's implications and the vital services that would be lost if marshes disappear, from nourishing marine species to providing a barrier for coastal communities during storms such as Hurricane Sandy. Read the interview
11 Dec 2012:
NASA Visualization Captures
Record Year for Wildfires in the U.S.
This year has been an unusually severe one for wildfires in the U.S., with more than 9.1 million acres of land burned through the end of November, federal officials say. The total affected area, which is depicted in a new NASA map, is already the third-largest since records were first kept
in 1960, and will likely break previous
records by year’s end. The most intense fires occurred in the western U.S., where several major fires during the early summer — sparked by a combination of drought, light winter snow pack, and the long-term effects of climate change — forced evacuations in some areas. In the visualization, which shows all fires that occurred between Jan. 1 and Oct. 31, areas of yellow and orange indicate larger and more intense fires, while many of the less intense fires, shown in red, represent prescribed burns started for brush clearing or agriculture and ecosystem management. The visualization was based on data collected by NASA satellites.
Interview: Designing Green Cities
To Meet 21st Century Challenges
Landscape architect Martha Schwartz is a passionate believer in the role that landscape can play in urban sustainability. Great landscape design, she says, can
Martha Schwartz Partners
moderate extreme heat, recycle water, reduce energy use, lower carbon emissions, and attract people to urban areas. Following these principles, her London-based firm, Martha Schwartz Partners
, has designed such projects as Dublin’s Grand Canal Square; Exchange Square, in Manchester, England; and Abu Dhabi’s Corniche beachfront area. In an interview with Yale Environment 360
, Schwartz, a professor at Harvard University’s Graduate School of Design, talks about the importance of incorporating cultural values in urban design, explains why the design of streets and parking lots is as important as the design of parks, and discusses why the U.S. lags behind many other nations in the greening of its cities. Read the interview
20 Nov 2012:
U.S.-Mexico Reach Accord
On Sharing Colorado River Water
The U.S. and Mexico have reached an agreement on how to share water from the Colorado River
, a five-year deal crafted to help both nations prepare for future droughts. Under the agreement, regional water agencies in California, Arizona, and Nevada will purchase nearly 100,000 acre-feet of water from Mexico’s share of the river, enough to cover 200,000 households for a year. In return, Mexico will receive $10 million to repair damage along hundreds of miles of irrigation canals caused by a 2010 earthquake — repairs that will bring thousands of acres of farmland back into production, according to the Los Angeles Times
. The U.S. will also promise to buy additional water and allow it to flow to the delta south of the border, a region that has seen reduced water flow in recent years
as U.S. water demands upstream have increased. In addition, Mexico will agree to take lesser water during periods of drought, but will be allowed to keep some of its water in Lake Mead
, the vast reservoir that straddles Nevada and Arizona, providing badly needed storage capacity.
02 Nov 2012:
Sea-Level Rise Projections
Ignored Critical Feedbacks, Researcher Says
A U.S. researcher says projected sea-level rise over the next century has been underestimated because current models fail to consider several critical feedbacks
that might accelerate rising seas in the coming decades. While the 2007 report of the Intergovernmental Panel on Climate Change predicted that global sea levels could rise 0.2 to 0.5 meters by 2100, current projections suggest that seas could rise a meter or more. One of the factors ignored by earlier models, says University of Colorado geologist Bill Hay, is the influx of warm, briny ocean water into the Arctic that occurs when melting fresh water is released, a phenomenon he says acts as a sort of “heat pump” in the Arctic, adding more ice-free waters, which then absorb more solar energy. According to Hay, who will present his findings at the annual meeting of The Geological Society of America, another factor that was ignored is the potential melting of large ice sheets in Greenland and western Antarctica. A third feedback, he said, is the vast amounts of groundwater being removed to address humankind’s surging water needs, much of which ultimately ends up in the oceans.
13 Sep 2012:
In Himalaya Mountains,
A Mixed Picture of Glacial Melting
A new study says that glaciers in the Himalayas are reacting to climate change in different ways
, with glaciers in the eastern and central Himalayas retreating at accelerating rates, while glaciers in the western Himalaya and Hindu Kush region are more stable and possibly even growing in places. According to a report by the National Research Council
, many of the glaciers of the Himalayan region are retreating at rates comparable to other parts of the world, but changes to glacial meltwater are not likely to make a significant difference in water availability at lower elevations, which rely more on monsoon rains and snowmelt. If the the current rate of glacial retreat continues, however, the report said that high-elevation areas of some river basins could see altered seasonal water flow. In addition, researchers say the melting of glaciers could affect regional water security during periods of drought or “similar climate extremes.” The Himalaya/Hindu Kush region is the source of several river systems — including the Indus, Ganges, and Brahmaputra — that supply drinking water and irrigation to 1.5 billion people.
06 Sep 2012:
Destruction of Tropical Forests
Reduces Regional Rainfall, Study Says
A new study has found that destruction of the world’s tropical forests may significantly reduce regional rainfall across large regions
, a phenomenon researchers say could have devastating effects for people living in and around the Amazon and Congo basins. Using satellite observations of rainfall and vegetation, as well as atmospheric wind flow patterns, researchers from the University of Leeds and the NERC Center for Ecology & Hydrology found that across 60 percent of the Amazon and Congo rainforests, air passing over extensive forest areas produces twice as much rain as air passing over areas with little vegetation. According to their findings, published in the journal Nature
, this effect in some cases can increase rainfall thousands of miles away. After combining these findings with projected deforestation rates and current trends, the researchers calculated that tropical forest loss could reduce rainfall across the Amazon basin during the wet season by 12 percent by 2050, and 21 percent during the dry season.
27 Aug 2012:
Desalination Sector Surges as
Technology Improves, Demand Grows
A new report predicts that global investment in water desalination projects will triple over a five-year period from 2011 to 2016
, driven by improvements in technology and a surge in companies entering the sector. According to Global Water Intelligence, investments in desalination plant installations will grow from $5 billion last year to $8.9 billion this year; by 2016, the report says, the sector could reach $17 billion. A critical factor has been the emergence of technologies that require less energy to make potable water from seawater, including a process called forward osmosis that uses less heat and power than existing reverse osmosis plants and could cut the cost of desalination by as much as 30 percent. Also driving this surge is growing demand in developing nations already facing water shortages, including China and India. “Those huge economies will not be able to step forward without a solution to water scarcity, and one of the solutions is going to be desalination,” Avshalom Felber, CEO of Israel-based IDE Technologies, told Bloomberg News.
24 Aug 2012:
Drought Conditions Trigger
Smallest Gulf ‘Dead Zone’ in Years
U.S. scientists say the nation’s worst drought in five decades has had at least one positive effect: the smallest so-called “dead zone” seen in the Gulf of Mexico in years
. In a 1,200-mile research cruise conducted in the
Algal blooms in the Gulf of Mexico
waters of the gulf this month, scientists from Texas A&M University found only 1,580 square miles of oxygen-depleted, or hypoxic, water in the gulf, compared with 3,400 square miles last August. The hypoxic zone is created when algal blooms, caused by large amounts of fertilizer and nutrients washing into the gulf, remove oxygen from the water and suffocate marine life. According to the researchers, hypoxia was found only in the waters near the Mississippi River delta, which accounts for nearly 90 percent of all freshwater runoff in the gulf; no hypoxia was observed off the Texas coast. “What has happened is that the drought has caused very little fresh-water runoff and nutrient load into the gulf, and that means a smaller region for marine life to be impacted,” said Steve DiMarco, an oceanographer at Texas A&M.
22 Aug 2012:
New Canadian Law Removes
Federal Oversight From Smaller Projects
Major revisions to Canada’s Environmental Assessment Act have stripped nearly 500 projects of federal oversight
in British Columbia alone, including major dam projects, gravel extraction operations, and the sinking of former warships as artificial reefs, according to a news report. The new screening assessments, the latest in a series of initiatives by Prime Minister Stephen Harper’s administration seen as weakening environmental regulation
, give an increased role in environmental oversight and enforcement to provinces. Speaking to the Vancouver Sun
, a spokesperson for the Canadian Environmental Assessment Agency said that the “numerous small, routine projects… posed little or no risk to the environment.” But Canadian environmental advocates warn that a reduced federal role in monitoring these hundreds of projects will ultimately place the province’s environment, particularly fish habitat, at increased risk. “The cumulative impacts of all the projects that they will no longer review will be great and it will take a few years for Canadians to appreciate that,” said Otto Langer, a former official with the federal fisheries department.
21 Aug 2012:
NASA Image Shows Low Waters
Of Drought-Stricken Mississippi River
A pair of NASA satellite images comparing water flow along the Mississippi River this month with August 2011
illustrates the effects of a severe summer drought along the critical waterway. The recent photo, taken just south
of Memphis, Tennessee on Aug. 8, reveals extensive sandbars that are newly exposed or far larger than they were a year ago. Numerous stretches of the river have become significantly narrowed by decreased water flow. The drought, the worst in 56 years, has left the Mississippi River at its lowest levels since 1988
, with some areas more than 12 feet lower than normal conditions at this time of year. Ninety-seven vessels were stranded by low waters near Greenville, Mississippi, where an 11-mile stretch of the river was closed for dredging. Near St. Louis, the U.S. Army Corps of Engineers has been forced to stop river traffic for up to 12 hours at a time in order to keep the shipping lane wide enough, according to Reuters.
16 Aug 2012:
Large Utah Tar Sands Mine
A Threat to Water Supplies, Groups Say
Two environmental organizations are fighting a Canadian company’s plan to mine a massive reserve of oil sands in eastern Utah, saying the project would tax water supplies in what is already the U.S.’s second-driest state
. In what would be the U.S.'s first large-scale oil sands mining operation, Calgary-based U.S. Oil Sands Inc. has already excavated a two-acre test mine at site called PR Spring and ultimately hopes to establish a sprawling, 6,000-acre mine as early as 2014. According to the Utah Geological Survey, about 25 billion barrels of bitumen are buried on state and federal land in this region — enough to meet the nation’s oil needs for more than three years. But according to a report by Inside Climate News
, it remains unclear whether there will be enough groundwater to support the industry long-term — not to mention the water needs of municipalities and private industries nearby. Two groups, Living Rivers and the Western Resource Advocates, are appealing U.S. Oil Sands’ mining permit, arguing that the state of Utah ignored the threat to groundwater supplies. According to a letter from the Utah Division of Oil, Gas and Mining, the mine is expected to use “116 gallons of water per minute on a 24-hour basis.”
16 Aug 2012:
Ocean Health Index Evaluates
State of Waters Around the Globe
An international team of researchers has released a new tool that evaluates the state of the world’s oceans
, a so-called Ocean Health Index that its creators say provides the first comprehensive assessment of the relationship
between the planet’s marine regions and human communities. While previous assessments of ocean health were based on the level of “pristineness,” this index is framed in terms of the benefits humans derive from the oceans and the extent to which communities maintain a sustainable marine environment. Using a wide range of criteria — including water quality, marine biodiversity, and the condition of coastal areas — the researchers ranked ocean areas worldwide on a scale from 0 to 100. According to their analysis, published in the journal Nature
, the global ocean received an overall score of 60, while scores for individual areas ranged from 36 to 86. The waters around Jarvis Island, near Hawaii, ranked highest
; the waters off the West African nation of Sierra Leone ranked lowest.
09 Aug 2012:
Overuse of Groundwater
Threatens Global Supplies, Study Says
A new study finds that nearly one-quarter of the world’s population lives in regions where water is being used faster than it can be replenished
. Using computer models of global groundwater resources and water use data, scientists from Canada and the Netherlands calculated that the planet’s “groundwater footprint” — the area above ground that relies on water from underground sources — is about 3.5 times larger than the aquifers themselves
. The study found that in most of the world’s major agricultural regions — including the Central Valley in California, the Nile delta region of Egypt, and the Upper Ganges in India and Pakistan— demand exceeds these reservoirs’ capacity for renewal. For example, the groundwater footprint for the Upper Ganges aquifer is more than 50 times the size of aquifer. “This overuse can lead to decreased groundwater availability for both drinking water and growing food,” said Tom Gleeson, a hydrologist at McGill University in Montreal and lead author of the study, published in the journal Nature
. According to the scientists, about 1.7 billion people, mostly in Asia, live in areas where water needs for humans and ecosystem services outstrip the ability of aquifers to replenish themselves.
31 Jul 2012:
Low Levels of Caffeine Found
In Waters of U.S. Pacific Northwest
In a new study, scientists document low levels of caffeine pollution in the waters off the Oregon coast, fresh evidence that contaminants from human waste are entering marine ecosystems with unknown risks to wildlife and human health. In a series of tests conducted at 14 coastal locations, researchers found that caffeine levels were higher — about 45 nanograms per liter — in remote waters, while levels were below reporting limits (about 9 nanograms per liter) near “potentially polluted” areas such as sewage treatment plants, the mouths of rivers, and larger communities, National Geographic reports
. According to the findings, published in the journal Marine Pollution Bulletin
, the higher levels are likely occurring near sites with on-site waste disposal systems that are subject to less monitoring than larger wastewater treatment plants. While the environmental effects of such low-level contamination are not known, experts say they are a reminder of the range of pollutants — from pharmaceuticals to artificial sweeteners — entering natural ecosystems through human waste.