18 Aug 2011:
Extreme Weather Disasters
Take Record Toll in U.S. in 2011
The U.S. has already tied the record for the number of extreme weather events causing more than $1 billion in damage in one year, with the cumulative tab so far reaching $35 billion
, government officials said. According to the National Oceanic and Atmospheric Administration (NOAA), there have been nine separate natural disasters
causing damages that totaled more than $1 billion, including summer flooding along the Missouri River, a crippling drought across the southern plains and Southwest, and a series of devastating tornadoes across the Midwest in April. “I don’t think it takes a wizard to predict 2011 is likely to go down as one of the more extreme years for weather in history,” Jack Hayes, director of the National Weather Service, told reporters, noting that the hurricane season has barely begun. While NOAA officials said there is an urgency to make the U.S. more “weather ready,” its administrator, Jane Lubchenco, warned that failure to fund a new satellite would make it impossible to forecast severe weather events
far enough in advance to save lives. In Texas, this summer’s record drought has caused an estimated $5.2 billion in crop and livestock losses
, by far the largest annual loss in state history.
18 Aug 2011:
UK Otter Populations Rebound
Two Decades After Near Extinction
Environmental officials say otter populations have returned to every county in the United Kingdom
, just two decades after pollution had nearly wiped them out. At least two otters have been found building homes
along rivers in Kent, the last county where the animals had not been found in recent decades, according to the UK’s Environment Agency. Wildlife experts say the animal began disappearing in the mid-1950s, probably as a result of powerful organochlorine pesticides washing into their river habitats. While the chemicals were banned in the mid-1960s, populations of the animal continued to decline; by the late-1970s, a study found otters in only 5 percent of sites where they once lived. Programs to clean up England’s rivers, which brought back fish to once-polluted waterways, and legal protection of the otter began to reverse the trend in the 1990s, as otters began to return eastward from strongholds in the west. The latest survey of otter populations, conducted between 2009 and 2010, found the animal in 60 percent of 2,940 locations where they were once found.
17 Aug 2011:
Water Risk Mapping Project
Attracts Major Global Companies
Several global corporations have joined a World Resources Institute project that is developing a new database and mapping tools to help companies manage their water resources and reduce risk. The Aqueduct project
— which so far has enlisted companies such as Coca-Cola, General Electric, and Dow Chemical
use hydrological modeling and a wide range of data to identify water supplies globally, track water use trends, and provide insights into regions facing potential risks, including physical, regulatory and socioeconomic factors. So far, the project has developed a water risk atlas that calculates risks associated with the Yellow River Basin in northern China. Later this year, the project will release similar mapping tools for other high-priority river basins, including the Colorado River in the U.S., the Murray Darling River in Australia, the Orange-Sequ River in Africa, and China’s Yangtze River. In addition to helping heavily water-dependent companies identify potential supply problems, the tool is expected to assist water and wastewater solutions companies in identifying regions and clients in need of risk mitigation.
11 Aug 2011:
U.S. Panel Endorses Fracking
As Members Are Faulted for Industry Ties
A U.S. Energy Department advisory panel has issued a qualified endorsement of the controversial shale gas exploitation technique of hydraulic fracturing,
but a group of scientists charges that the panel’s recommendations are tainted because six of its seven members have current financial ties to the natural gas industry. The panel’s report says that hydraulic fracturing, or “fracking,” could be a productive way of extracting natural gas if the industry follows a set of strict guidelines. These include disclosing the chemicals used in the fracking process, adopting rigorous standards for air pollution emissions from fracking wells, and monitoring nearby water supplies for contamination from fracking. But the panel is largely silent on which state or federal agencies should regulate fracking, and whether regulators should apply to it laws such as the Safe Drinking Water Act. The Environmental Working Group (EWG) issued a letter, signed by 28 scientists from 22 universities, criticizing the panel for its industry ties,
including more than $1.4 million paid to panel chairman John Deutch of MIT from 2006 to 2009. The EWG accused the panel of conducting “advocacy-based science” and said that at a minimum Deutch should be replaced by a person with no industry ties.
09 Aug 2011:
Israel Expands Desalination;
Study Touts New Salt-Removing Technology
Israel has announced plans to build a $423 million (1.5 billion shekel) desalination plant in the Mediterranean coastal city of Ashdod that officials say will provide 100 million cubic meters of water annually
, or about 15 percent of the nation’s drinking water needs. When completed in 2013, the reverse osmosis plant will join four other Israel plants that combined will meet three-quarters of the nation’s household water needs. Finance Minister Yuval Steinitz said expansion of desalination operations is critical as Israel looks to prevent depletion of its main freshwater source, the Sea of Galilee. Meanwhile, a recent Yale University study
found that desalination technology could provide the best hope for meeting the world’s growing water needs. But rather than using reverse osmosis technology, which researchers say is nearing its potential for maximum energy efficiency, researchers suggest that the greatest efficiency gains could occur in pre- and post-treatment stages of desalination. “All of this will require new materials and a new chemistry, but we believe this is where we should focus our efforts going forward,” said Menachem Elimelech, a Yale professor of chemical and environmental engineering.
05 Aug 2011:
Rising CO2 Levels Could Offset
Drying Effects of Higher Temperatures
As the world warms, rising temperatures are expected to dry out the planet’s semi-arid rangelands. But a new study by U.S. scientists suggests that the effects of that drying are likely to be offset
by the way in which plants react to elevated concentrations of CO2 in the atmosphere. Higher temperatures increase water loss to the atmosphere, but scientists from the U.S. Department of Agriculture (USDA) found that higher CO2 levels also cause leaf pores, or stomata, to partially close, which actually slows the evaporation process. The scientists are conducting an 8-year study on dry grasslands in Wyoming, and are simulating future climate conditions — when temperatures could rise by 5 degrees F and atmospheric CO2 concentrations could soar from today’s 390 parts per million to 600 ppm — by using infrared heaters and CO2 piped into experimental plots. The preliminary results of their studies, published in the journal Nature
, show that dry grasslands are likely to experience no change in soil water and that warm season grasses may actually grow more quickly under future climate conditions. Dry rangelands make up roughly one third of the Earth’s surface and USDA scientists say their research may help ranchers and farmers plant grasses and crops that are likely to fare better as temperature and CO2 levels increase.
03 Aug 2011:
Crops With Deeper Roots
Could Boost CO2 Storage, Study Says
Breeding crops with deeper roots could significantly reduce atmospheric levels of carbon dioxide
and make crops more drought resistant, according to a study by a researcher at the University of Manchester. Reporting in the journal, Annals of Botany
, professor Douglas Kell calculated that breeding crops whose roots extend 2 meters underground, rather than the 1-meter roots common to many crops, could double the amount of carbon captured from the atmosphere. Kell reported that creating crops and plants with deeper and bushier roots would also lead to more water and nutrient retention and produce more sustainable plant yields as the world warms and droughts increase in water-stressed regions. “This doubling of root biomass from a nominal 1 meter to 2 meters is really the key issue,” said Kell.
25 Jul 2011:
U.S. Land in Flood Plains
Could Increase 45 Percent, Study Says
The amount of U.S. land located within flood plain zones is expected to increase by 40 to 45 percent
by the end of this century, according to a study of the impacts of climate change on the federal flood insurance program. The study, which will be released later this summer, projects that a widening threat of rising waters along ocean coastlines and in river valleys as a result of climate change — including rising seas, greater downpours and more intense coastal storms — could double the number of policies in the National Flood Insurance Program (NFIP) by 2100, ClimateWire
reports. The federal program now insures about 5.6 million homes and businesses and is valued at $1.2 trillion. Mark Crowell, a geologist with the Federal Emergency Management Agency (FEMA), told a conference that the findings suggest “a need for FEMA to incorporate the effects of climate change more directly into various aspects of the NFIP.” A recent study predicted that rising sea levels could inundate 9 percent of the land in 180 U.S. cities
14 Jun 2011:
Severe Drought in Europe
Threatens Crops and Nuclear Power Output
One of Europe’s most severe droughts in a century is threatening crop production, shrinking some rivers to near-record low levels, and raising the specter that France may experience blackouts as some river-cooled
nuclear power plants may be forced to shut down
. In France, the warmest and driest spring in half a century may significantly slash wheat yields. In addition, with 44 of France’s 58 nuclear reactors cooled by river water, officials are closely monitoring whether power production may have to be reduced, since sending overheated water from the plants back into low, warm rivers could cause major ecological problems. In Germany, where spring water levels in many rivers are the lowest they’ve been in a century, yields of crops such as rapeseed oil are expected to drop by 20 percent. And England’s southeast, the country’s breadbasket, is experiencing a severe drought, while many other parts of the UK are on the brink of drought. Overall, rainfall across Europe this year is only 40 to 80 percent of the average precipitation from 1951 to 2000.
17 May 2011:
New Geothermal System Taps
Heat Without Geological Risks, Firm Says
A U.S. startup says it has developed an enhanced geothermal system (EGS) that engineers say can tap into heat from the Earth’s interior without any associated risks of triggering earthquakes or polluting underground aquifers
. While typical EGS processes require developers to pump liquids into deep wells at high pressure, a process that has on occasion trigged small earthquakes, GTHerm
has developed an approach that doesn’t require fracturing or water cooling. Instead, the process includes installation of a solid-state heat exchanger, or “heat nest,” at the bottom of the well that can more efficiently draw heat from surrounding rock with the help of a highly conductive grout encasing the heat exchanger. Fluid is sent down the well in a closed loop that carries the heat back to the surface, where it creates steam that drives electricity-generating turbines. “We’re basically a heat pump on steroids,” said Michael Parrella, CEO and founder of the Connecticut-based company. The company, which is now testing the commercial feasibility of the technology, hopes to have demonstration plants in place as early as 2012.
26 Apr 2011:
Future Water Stress
Detailed In U.S. Report on Western States
A new U.S. government report on water in the American West in the 21st century forecasts that temperatures in the region will soar by 5 to 7 degrees F., major rivers such as the Rio Grande and Colorado could
Click to enlarge
U.S. Department of Interior
Projected precipitation change, 2070-2099
see reductions in flow of up to 20 percent
, and less snow will fall and will melt earlier. The report
, released by the U.S. Department of the Interior, said that while the Pacific Northwest is likely to see an increase in precipitation in the 21st century, the southwestern U.S. will become even drier, seriously straining water supplies in a region whose population has been rising rapidly in recent decades. The report, presented by Interior Secretary Ken Salazar, analyzed future water conditions in eight major western river basins, from the Columbia River in Oregon and Washington to the Rio Grande along the Mexican border. Overall, the report said, the region can expect a decline in the April 1st snowpack, which means that many western rivers are likely to experience significant reductions of flow in the summer. The report also said that the increasing use of water in drilling for natural gas in underground shale formations is likely to further strain the West’s water supplies.
25 Apr 2011:
U.S. Company Halts “Fracking”
While It Investigates Causes of Blowout
A large U.S. producer of natural gas from underground shale formations says it will suspend the controversial drilling practice of hydraulic fracturing
, or fracking, at seven well sites until it has investigated the causes behind a drilling accident last week. Chesapeake Energy has halted its fracking operations following a blowout in Bradford County in northeastern Pennsylvania that led to a spill of thousands of gallons of drilling fluid. Fracking — which involves blasting a mixture of water, sand, and chemicals deep underground to shatter shale formations and free natural gas trapped within — now accounts for 23 percent of U.S. natural gas production. But the rapid spread of hydraulic fracturing is causing increasing concern among environmentalists and some local residents
, who contend the process is leading to pollution of water supplies in regions rich in shale-gas. Chief among these regions is the Marcellus Shale formation, which extends across various eastern states, including Pennyslvania. Because of these concerns, fracking is currently banned in some regions, including the watershed for New York City’s water supplies
Invasive Mussels Trigger
Major Ecological Shift in Great Lakes
The rapid spread of non-native mussels in the Great Lakes has caused an unprecedented ecological shift in lakes Michigan and Huron
, stripping the massive freshwater lakes of life-supporting algae, according to a new study by University of Michigan researchers. While
Michigan Sea Grant
A quagga mussel
the increased number of zebra mussels has been observed in the lakes for decades, an even greater threat in recent years has been the spread of the closely related quagga, a fingernail-sized mussel that thrives in the lakes’ deep muddy bottoms. Each quagga mussel, billions of which now blanket the bottoms of lakes Huron and Michigan, filters about a quart of water daily, and feeds on algae that is a critical food source for other lake organisms — including the shrimplike Diporeia, which has long been a pillar of the Great Lakes’ food chain. Researchers say algal production in both lakes in 2008 was 80 percent lower than in the 1980s, a phenomenon that coincided with the spread of the quagga. “These are astounding changes, a tremendous shifting of the very base of the food web in those lakes into a state that has not been seen in the recorded history of the lakes,” said Mary Anne Evans, lead author of the study, which will be published in the journal Environmental Science & Technology
17 Mar 2011:
Canada’s Boreal Forest Holds
Largest Store of Unfrozen Freshwater
Canada’s 1.3 billion-acre boreal forest contains more unfrozen freshwater than any other ecosystem on the planet
, according to a new report by the Pew Environmental Group. With about 25 percent of the world’s wetlands, millions of lakes, and thousands of rivers, the boreal forest contains about 197 million acres of freshwater. Its extensive undammed rivers are a refuge for many of the planet’s sea-run migratory fish, including half of the remaining populations of North Atlantic salmon. And its role as a massive carbon vault provides an estimated $700 billion annually as a buffer to climate-related food and water shortages globally, according to the report, which is the first of its kind. But the Canadian boreal has also been increasingly targeted for large-scale industrial activities, with more than 180 million acres already affected by forestry, road building, mining, oil and gas extraction, and hydropower. While more than 12 percent of the boreal is already strictly protected, the report recommends more water-focused conservation efforts, including conservation of the entire Mackenzie River watershed.
14 Mar 2011:
African Corn Faces Threat
From Even Moderate Warming, Study Shows
A review of crop trial data from thousands of sites across Africa shows that a temperature increase of 1 degree C (1.8 F) could cause declines in corn harvests in two-thirds of the continent’s maize-growing regions
. Drawing on previously unstudied data from 20,000 trials of corn yields across Africa from 1999 to 2007, an international team of researchers found that the longer corn crops are exposed to temperatures above 30 degrees C (86 F), the more yields decline. And under drought conditions, the researchers found that more than 75 percent of corn-growing regions suffered yield declines of at least 20 percent as temperatures rose 1 degree C. Researchers from the International Maize and Wheat Improvement Center, reporting in the journal Nature Climate Change
, said the results surprised them because maize was assumed to be among the more heat-tolerant crops. The researchers reached their conclusions after gathering data from the 20,000 trial sites and then comparing it with temperature and rainfall data. They said the results show that corn, a staple crop for many Africans, could suffer significant yield declines if, as predicted, higher temperatures and drought impact Africa in the future.
11 Mar 2011:
China Commits $30 Million
To Clean Up Polluted River in E360 Video
Chinese officials said the government is planning to spend 200 million yuan ($30 million) to clean up the Baojiagou River, a badly polluted waterway that is the subject of "The Warriors of Qiugang," the Academy Award-nominated film
co-produced by Yale Environment 360
. China Daily
reported that Chen Yun, head of the Bengbu City Environment Protection Bureau, said the city is planning to invest the money in water-quality improvements
. The government also invited local people to report any cases of pollution to officials, according to China Daily
. "The Warriors of Quigang" – which was nominated for a 2011 Academy Award for Best Documentary (Short Subject) and can be seen online exclusively at Yale Environment 360
– documents the struggle of the people of Qiugang against a polluting chemical factory in their village that was poisoning their air, their fields, and their drinking water; the plant was eventually shut down in late 2008 and was relocated.
04 Mar 2011:
As CO2 Levels Have Risen,
Plants Are Releasing Less Water, Study Says
A study of plant samples from the past 150 years shows that as atmospheric concentrations of carbon
dioxide have steadily increased, the density and size of pores that allow plants to breathe has decreased, also reducing the plants’ transpiration of water
. The undersides of leaves contain pores, or stomata, that enable plants to absorb CO2 and release water into the air. When researchers at Indiana University and Utrecht University in the Netherlands examined leaves from Florida herbarium collections dating back 150 years, and compared them with leaves from the same plant species today, they found that the density of stomata has decreased 34 percent, presumably because greater atmospheric concentrations of CO2 have enabled the plants to absorb sufficient CO2 with fewer pores. That decrease in stomata has led to a “huge reduction in the release of water into the atmosphere,” said one of the researchers. These change have occurred as atmospheric concentrations of CO2 have risen from about 290 parts per million to 390 million today. Should CO2 concentrations double in the future, the researchers — reporting in the journal Proceedings of the National Academy of Sciences
— said that the amount of water released by plants could be cut by half, which would have a profound impact on the global hydrological cycle.
03 Mar 2011:
Control of Invasive Shrub with
Asian Beetles Yields Huge Water Savings
Researchers say an Asian beetle may help control the spread of tamarisk
, an invasive Eurasian shrub responsible for water loss across the southwestern United States. After allowing the tamarisk leaf beetle to devour leaves for one year in a 4,500-acre area dominated by the shrub in the Great Basin of Nevada, scientists from the University of California Santa Barbara (UCSB) found that about 2,500 acre-feet of water that would have otherwise been consumed by the plant remained in the ground. “This is roughly the same amount of water that would be used to irrigate 1,000 agricultural acres in a year,” said Tom Dudley, a UCSB biologist. At about $185 per acre-foot, this amount of water could provide annual water needs for 5,000 to 10,000 households, he said. Introduced into North America more than a century ago, tamarisk, also known as saltcedar, now occupies more than a million acres of riverside habitat
, displacing native trees, degrading habitat quality for wildlife and exacerbating erosion and sedimentation. The shrub is also flammable, which increases the risks of wildfire.
For the last two decades, strange things have been happening to frogs. Some frog populations have high rates of limb deformities, while others have high incidences of “intersex” — traits associated with both males and females, such as male
David K. Skelly
frogs whose testes contain eggs. David K. Skelly, professor of ecology at Yale University’s School of Forestry & Environmental Studies, set out to discover what was causing these deformities, which some researchers were attributing to an agricultural pesticide. His work has implicated human activity, but not in the way many researchers had thought. In an interview with Yale Environment 360
, Skelly describes what chemicals may be causing these abnormalities and explains why this phenomenon may have troubling implications not only for amphibians, but for other vertebrates, including humans. Skelly says one thing is clear: The deformities showing up in frogs are almost certainly not caused by a single chemical, but rather by a whole suite of substances — including medicines excreted by humans into the environment — that act in concert to mimic hormones like estrogen or cause other ill effects.
Read the interview
17 Feb 2011:
Heavier Downpours Linked
To Increasing Greenhouse Gas Emissions
A comprehensive computer analysis of heavy precipitation events in the Northern Hemisphere from 1951 to 1999 has shown that the intense downpours that have hit many countries in recent decades are at least partly the result of human influence on climate
. Reporting in the journal Nature
, a team of climate scientists said their analysis showed that the likelihood of extreme precipitation on any given day rose by about 7 percent over the last half of the 20th century. The study, the first of its kind, said that detailed computer analyses showed that the increase in severe rainstorms and heavy snowfalls could not be explained by natural variability in the atmosphere. The study did not include the many extreme precipitation events of the past decade, including catastrophic floods in Pakistan, China, Australia, the United Kingdom, and parts of the United States. The study seems to confirm what many climate scientists have been forecasting for years — that as the Earth warms, heavy precipitation events will become increasingly common because warmer air carries more water vapor.
24 Jan 2011:
New Water Resource Tool
Maps Ground Permeability Worldwide
Canadian researchers have produced a map illustrating the permeability of the porous surface rocks and sediments worldwide
, a tool they say will emerge as a critical resource in water resource management and climate modeling. Using recent lithology results documenting rock types worldwide, scientists at the University of British Columbia were able to map how easily fluids should be able to flow at depths of more than 325 feet (100 meters). Earlier models achieved depths of only about 6 ½ feet (2 meters). “Using our permeability data and maps, we can now evaluate sustainable groundwater resources as well as the impact of groundwater on past, current and future climate at the global scale,” said Tom Gleeson, a researcher at UBC and lead author of the study
published in Geophysical Research Letters
. Groundwater accounts for about 99 percent of the fresh, unfrozen water on the planet.
21 Jan 2011:
Species of ‘Bearded’ Crayfish
Discovered in Waters of U.S. South
U.S. biologists have discovered a new and distinct species of crayfish
in Tennessee and Alabama that is twice the size of other species, an example of a new species being discovered in a well-explored area.
Courtesy of Carl Williams
Researchers from the University of Illinois at Urbana-Champaign and Eastern Kentucky University found the first specimen under a large rock in the deep waters of a Tennessee creek after hearing reports of similar findings. The new species of crustacean, called Barbicambarus simmonsi
, is about five inches long and has an unusual “bearded” antennae as a result of the presence of tiny hair-like bristles called setae. “This isn’t a crayfish that someone would have picked up and just said, ‘Oh, it’s another crayfish,’ and put it back,” said Chris Taylor, curator of crustaceans at the Illinois Natural History Survey and co-discoverer of the crayfish. Researchers say the species is extremely difficult to find; it took numerous visits to the region to find enough samples to confirm that they had discovered a new species.
18 Jan 2011:
Groundwater Overuse May Make
Arsenic More Common in South Asian Wells
A century of exploitation of groundwater supplies has drawn down water tables across Vietnam, making it difficult to avoid water contaminated with arsenic even at deeper depths
, according to a new study. In tests of 512 private wells reaching depths of 10 to 50 meters (33 to 164 feet), researchers found that 27 percent contained arsenic levels exceeding World Health Organization health standards, putting 3 million people at risk. In the region around densely-populated Hanoi, it has become difficult to tap water that is not contaminated no matter how far down drills reach, according to the study published in the journal Nature
. According to researchers, it may be likely that the toxic element could become common in deep aquifers across South Asia, posing significant health risks and economic costs associated with water purification. Exposure to arsenic can trigger numerous conditions, from lesions, to anemia to cancer.
14 Jan 2011:
U.S. Revokes Permit For
Biggest Mountaintop Removal Project
The U.S. Environmental Protection Agency (EPA) has revoked a permit for a large mountaintop removal mining project in West Virginia
, saying it would use “destructive and unsustainable mining practices” that would threaten the health and water supplies of the surrounding Appalachian communities. While the EPA said mining projects elsewhere in the state could continue, agency officials rescinded a permit under the Clean Water Act
for Arch Coal’s proposed 2,300-acre Spruce Mine operation in Logan County, a controversial project that would dump mining debris into more than 7 miles of rivers. The decision could affect dozens of other mountaintop removal mining projects, in which companies blast off the tops of mountains
to get at the coal seams below. Across Appalachia, the practice has buried more than 2,000 miles of streams and damaged more than a million acres of forest. Peter Silva, EPA’s assistant administrator for water, said, “We have a responsibility to protect water quality and safeguard the people who rely on clean water.” Watch an e360 video on mountaintop mining
06 Jan 2011:
Satellites Will be Used
To Better Manage Irrigation Projects
NASA researchers have developed a computer program that will use satellite data, information from wireless sensors in fields, and weather observations to help farmers more efficiently irrigate their fields
. Irrigation accounts for nearly 70 percent of water use in the U.S., and NASA scientists say that their high-tech approach could improve irrigation efficiency by 20 to 25 percent.
Satellite view of Salinas, Calif.
NASA is doing a test project with farmers and vineyard managers in California’s San Joaquin Valley, one of the most intensively farmed regions in the U.S. The project will combine temperature and moisture data from soil sensors with satellite data on crop growth to estimate irrigation needs of individual farms and then distribute that information in near real-time to farmers via computers or hand-held devices. Using that information, farmers can precisely determine how much water to release into their fields and vineyards, enabling them to use less water to produce the same yield.
20 Dec 2010:
Market for Desalination Plants
Expected to Grow by $87 Billion by 2016
More than $88 billion will be invested in desalination technologies worldwide from 2010 to 2016
as regions face dwindling supplies of freshwater and steep population growth, according to a new report. Declining costs associated with several key desalination technologies — including reverse osmosis — will make saltwater-to-freshwater treatment a more affordable option, according to the report by Pike Research. “Desalination is becoming more affordable; thus, an increased number of people can benefit from an almost unlimited resource — seawater,” the report says. The global installed capacity is expected to grow by about 55 million cubic meters per day during that period, representing a 9-percent annual growth rate. About 54 percent of that growth will occur in the Middle East and North Africa.
10 Dec 2010:
Increasing Drought Seen
As Temperatures Rise in U.S., Study Says
A comprehensive study of 99 water sub-basins in the United States shows that rising temperatures, which cause more evaporation and reduce soil moisture, will increase the likelihood of drought
in many areas of the U.S. Earlier studies have shown that meteorological drought, based on shifting precipitation patterns in a warming world, was likely to affect regions such as the southwestern U.S. But Gary Yohe of Wesleyan University, along with colleagues from MIT and Industrial Economics Inc., looked at the prospects for hydrological drought, which is based on both precipitation and the effects of rising temperatures. Looking at three different CO2 emissions scenarios, Yohe and his colleagues said they were confident that the impacts of hydrological drought on agriculture and water availability would be increasingly negative and widespread as temperatures increase. The southwestern U.S. and Rocky Mountain states are projected to see the largest increases in drought frequency. The study, published in Environmental Research Letters
, said that with good planning, these regions should be able to soften the impact of increasing droughts by exploiting excess water storage capacity.
08 Dec 2010:
Increased Plant Growth Caused
By Rising C02 Could Have a ‘Cooling Effect’
Increases in plant growth expected as a result of a projected doubling of carbon dioxide levels in the atmosphere could create a cooling effect that would help reduce future global warming
, according to new NASA computer models. Specifically, researchers say that increased leaf growth that occurs when more carbon dioxide is in the atmosphere will likely increase evapotranspiration, which will have a cooling effect. According to the new model, this cooling effect would offset warming temperatures by 0.3 degrees C (0.5 degrees F) globally and 0.6 degrees C (1.1 degrees F) over land, compared to models in which the effects were not included, said Lahouari Bounoua, a researcher at the Goddard Space Flight Center and lead author of the study published in the journal Geophysical Research Letters
. The cooling effect would not be strong enough to offset rising temperatures, Bounoua said, but would temper those increases.
06 Dec 2010:
Coal-based Pavement Sealant
Is Leading Source of Toxin in U.S. Lakes
A coal-based sealant sprayed on pavement for parking lots, playgrounds, and driveways is the leading contributor of a toxic pollutant found in U.S. lakes and reservoirs
, according to a new study. Samples of sediments collected from the bottom of lakes and reservoirs in 40 urban areas by the U.S. Geological Survey revealed high levels of polycyclic aromatic hydrocarbons (PAHs), a probable carcinogen that is also toxic to fish and other marine life. On average, about half of the PAHs came from coal-tar sealants. Vehicles account for about one-fourth of the remaining pollutants, and coal combustion contributes about 20 percent, according to the study, published in the journal Science of the Total Environment
. Coal-tar pavement sealants — derived from the waste produced in the coking of steel — have been banned in several U.S. cities, including Austin, Texas, and Washington, D.C. An alternate asphalt-based sealant contains levels of PAHs that are 1,000 times lower than coal-tar sealants
03 Dec 2010:
Toxic Pollutants Found
at Remote Heights of Mount Everest
Scientists have found harmful levels of heavy metal pollutants on remote reaches of Mount Everest
, an indication of the great distances industrial air pollution can travel. Every snow sample collected at altitudes between 5,334 and 7,772 meters (17,500 to 25,498 feet) contained levels of cadmium and arsenic that exceeded U.S. safety standards, according to researchers at the University of Southern Maine in Gorham, while every soil sample contained unsafe levels of cadmium. According to the study
, published in the journal Soil Survey Horizons
, toxin levels were highest toward the top of the mountain, which suggests that high-altitude winds had carried the toxins from Asian industrial sites. Researchers called the results a reason for concern because mountaineers rely on melted snow for drinking water and high winds may also kick up toxins located in the soil. “People at Everest base camp often wear ventilators, simply because there is so much dust,” said Samantha Langley-Turnbaugh, one of the researchers.