Biodiesel won't drive down global warming

Biodiesel won't drive down global warming

EU legislation to promote the uptake of biodiesel will not make any difference to global warming, and could potentially result in greater emissions of greenhouse gases than from conventional petroleum derived diesel. This is the conclusion of a new study reported today in Chemistry & Industry, the magazine of the SCI.

Analysts at SRI Consulting compared the emissions of greenhouse gases by the two fuels across their overall life cycles from production to combustion in cars.

The results show that biodiesel derived from rapeseed grown on dedicated farmland emits nearly the same amount of greenhouse gas emissions (defined as CO2 equivalents) per km driven as does conventional diesel.

However, if the land used to grow rapeseed was instead used to grow trees, petroleum diesel would emit only a third of the CO2 equivalent emissions as biodiesel.

Petroleum diesel emits 85% of its greenhouse gases at the final stage, when burnt in the engine. By contrast, two-thirds of the emissions produced by rapeseed derived biodiesel (RME) occur during farming of the crop, when cropland emits nitrous oxide (N2O), otherwise known as laughing gas, that is 200-300x as potent a greenhouse gas as CO2.

The results of this analysis should have big implications for policymakers. The 2003 EU Biofuels Directive aims to increase the levels of biofuels to 5.75% of all transport fuels by 2010, up from roughly 2% currently. This will be further increased to a 10% share in 2010, the Commission announced in January this year.

Transportation currently accounts for more than a fifth of all greenhouse gas emissions emitted in the EU. Rapeseed-derived biodiesel is the major renewables-derived biofuel used across Europe and, as well as helping to improve energy security, is expected to play an important role in helping to meet the EU's Kyoto commitment to reduce levels of greenhouse gas emissions by 8% by 2012 relative to 1990 levels, and by 20% by 2020.

Scientists Track Impact of Asian Dust and Pollution on Clouds, Climate Change

Scientists Track Impact of Asian Dust and Pollution on Clouds, Climate Change

Scientists using one of the nation's newest and most capable research aircraft are launching a far-reaching field project this month to study plumes of airborne dust and pollutants that originate in Asia and journey to North America.

The plumes are among the largest such events on Earth, so great in scope that scientists believe they might affect clouds and weather across thousands of miles while interacting with the Sun's radiation and playing a role in global climate.

Known as PACDEX (Pacific Dust Experiment), the project will be led by scientists at the National Center for Atmospheric Research (NCAR) and the Scripps Institution of Oceanography. NCAR's main sponsor, the National Science Foundation (NSF), will provide most of the funding. The first mission will be launched in late April, depending on weather patterns in Asia. It will continue for two months.

To study the changes in the plumes as they move through the atmosphere from Japan to the western United States, the PACDEX team will deploy the NSF HIAPER, a modified Gulfstream-V aircraft, which is operated and maintained by NCAR. This newly configured plane has a range of about 6,000 miles and can cruise from just a few hundred feet above Earth's surface to over 50,000 feet. These features enable scientists to study the plumes across thousands of miles and at different levels of the atmosphere.

"Aerosol pollutants, such as those to be studied in PACDEX, account for the largest uncertainties in climate forcing," said Jay Fein, program director in NSF's Division of Atmospheric Sciences, which funded the experiment. "PACDEX is addressing this challenging and societally relevant science question."

While many particles in the plumes, such as sulfates, cool the planet by blocking solar radiation from reaching Earth, some particles such as black carbon absorb sunlight as well and therefore may amplify the effects of global warming. PACDEX will help scientists refine computer models of greenhouse gas emissions and improve forecasts of future climate change, both for the entire globe and for specific regions that are especially affected by dust and pollutants.

"PACDEX will open a window into what happens to the atmosphere as these massive plumes cross the Pacific Ocean and affect clouds, precipitation, and the amount of sunlight that reaches Earth," explains NCAR scientist Jeff Stith, a principal investigator on the project. "We want to determine how the various particles of dust and pollutants influence clouds and climate, and how far downwind those effects occur."

"PACDEX comes at a crucial time in our efforts to understand the regional impacts of global warming," says V. Ramanathan, a PACDEX principal investigator based at the Scripps Institution of Oceanography. "It will also help us help us examine how the dust and soot modifies storm tracks and cloud systems across the Pacific, which influence North American weather patterns in major ways. By focusing on these plumes, PACDEX will shed light on one of the major environmental issues of this decade."

As Asia's economies boom, scientists are increasingly turning their attention to the plumes, which pack a combination of industrial emissions (such as soot, smog, and trace metals) and dust from storms in regions such as Central Asia's Gobi Desert.

The plumes can alter global temperatures by interacting with large-scale, mid-latitude cloud systems over the Pacific that reflect enormous amounts of sunlight and help regulate global climate.

The plumes also may affect regional precipitation patterns because water vapor molecules adhere to microscopic particles of dust and pollutants to form water droplets or ice particles that eventually grow and fall out of the clouds as rain or snow.

In addition, the dust and pollutants reduce the amount of light reaching Earth, contributing to a phenomenon known as global dimming that can affect both temperatures and precipitation.

The Gulfstream-V will carry an array of instruments that will enable scientists to both measure clouds and bring dust, pollutants, and cloud particles into the aircraft for study. Scientists will capture ice particles from clouds, evaporate them, study the residue, and then try to recreate the particle in a special moistened chamber to mimic the temperature and moisture conditions that enabled the original ice particle to form.

The international research team will include scientists from U.S. and Asian organizations.

U.S. organizations include NCAR, Scripps, NASA, NOAA, Arizona State University, Colorado State University, Naval Research Laboratory, Oregon State University, University of Alaska, University of Colorado, and the University of Iowa.

Asian organizations include the Japanese National Institute for Environmental Studies, Lanzhou University and Peking University in China, and Seoul National University in Korea.

Undersea vent suggests snake-headed mythology

Undersea vent suggests snake-headed mythology | Science Blog

A new "black smoker" -- an undersea mineral chimney emitting hot, iron-darkened water that attracts unusual marine life -- has been discovered at about 8,500 feet underwater by an expedition currently exploring a section of volcanic ridge along the Pacific Ocean floor off Costa Rica.

Expedition leaders from Duke University; the Universities of New Hampshire, South Carolina and Florida; and the Woods Hole Oceanographic Institution (WHOI) in Massachusetts have named their discovery the Medusa hydrothermal vent field. The researchers are working aboard WHOI's research vessel Atlantis, and the expedition is funded by the National Science Foundation.

The researchers picked that name to highlight the presence of a pink form of the jellyfish order Stauromedusae as well as numerous spiky tubeworm casings that festoon the vent chimney and bring to mind "the serpent-haired Medusa of Greek myth," said expedition leader Emily Klein, a geology professor from Duke's Nicholas School of the Environment and Earth Sciences http://www.nicholas.duke.edu/ .

The bell-shaped jellyfish sighted near the vent "are really unusual, and the ones we found may be of a different species because nobody has seen types of this color before," added Karen Von Damm, an earth sciences professor and hydrothermal vent specialist on the expedition from the University of New Hampshire's Institute for the Study of Earth, Oceans and Space http://www.eos.sr.unh.edu/.

The scientists are exploring the ocean bottom with Jason II http://www.whoi.edu/marops/vehicles/jason/, a remotely controlled robotic vehicle operated by WHOI. Using Jason's mechanical arms and a temperature probe, they logged water temperatures of 335 degrees Celsius (635 degrees Fahrenheit) at the vent's opening.

"Despite the great temperature of the vent water, it doesn't boil until 390 C because pressures on the ocean floor are so great, about 200 times the pressure at sea level," Klein said. The tremendous pressures result from the weight of almost two miles of seawater pressing down from above.

"Frankly, it's astonishing that a rich ecology thrives in these extreme environments," Klein added. She noted, however, that while all the organisms near vents are adapted to the high pressures at these depths, not all experience extremely high temperatures.

"The temperature of the ocean floor is about 2 C (35 F) and there is a strong temperature gradient as you move away from the vent, so animals living a few inches away may experience temperatures only a few degrees above normal for the ocean floor."

Von Damm said that the heat-tolerant tubeworms found living on Medusa's chimneys, a type known as Alvinellids, are commonplace on vents in the equatorial Pacific and thrive on high-iron fluids.

According to the expedition's website, http://www.nicholas.duke.edu/OSCexpedition/, Jason has also retrieved two other types of tubeworms -- Tevnia and Riftia -- from the vent area for expedition scientists and graduate students to examine and preserve.

The researchers aboard Atlantis are on the scene principally to study the geology of a complex section of the East Pacific Rise, one of the "mid-ocean ridge" systems where new crust is made as the earth spreads and releases molten lava.

According to Von Damm, scientists often have found mid-ocean ridges wherever there are geothermal vents warmed by heat energy from the underlying volcanic conduits. "Each new vent sighting sparks fresh excitement, because each one is different," she said.

"Every vent has a little different chemistry, and that helps us understand the processes going on in the ocean crust," she said. "Each one gives us a different piece of the puzzle. And biologists have found more than 500 new species at vents since they were first discovered."

The Medusa vent was discovered on Easter Sunday morning, right after the scientists aboard Atlantis had completed an Easter egg hunt. Scott White, a geology professor from the University of South Carolina, had just come on duty as the watch leader when Jason II found an area rich in the types of organisms typically found near vents.

"We all knew it would be special when we found all the creatures living there after looking at relatively barren lava flows for several days," White said. He diverted the robot to investigate the animals more closely and "within seconds there was a spire of a hydrothermal chimney looming out of the darkness at the edge of Jason's camera lights," he added.

Vent specialist Von Damm had just begun the watch shift when the first black smoker image appeared on a video screen in the Jason II control room. Since Jason's video output is also piped to screens elsewhere around Atlantis, Klein saw it at about the same time.

"Suddenly everybody came running from all over the ship to see what was going on," Von Damm recalled. "I was smiling a lot. I was very happy."

"I jumped out of my chair and went running up a deck to see it in person," added Duke's Klein. "I have been going to sea for 20 years and have been hoping to find my first hydrothermal vent site, and finally I have.

"And I'm ecstatic."

Climate catastrophes in the Solar System

Climate catastrophes in the Solar System

Earth sits between two worlds that have been devastated by climate catastrophes. In the effort to combat global warming, our neighbours can provide valuable insights into the way climate catastrophes affect planets.

Modelling Earth's climate to predict its future has assumed tremendous importance in the light of mankind's influence on the atmosphere. The climate of our two neighbours is in stark contrast to that of our home planet, making data from ESA's Venus Express and Mars Express invaluable to climate scientists.

Venus is a cloudy inferno whilst Mars is a frigid desert. As current concerns about global warming have now achieved widespread acceptance, pressure has increased on scientists to propose solutions.

The key weapon in a climate scientist's arsenal is the climate model, a computer programme that uses the equations of physics to investigate the way in which Earth's atmosphere works. The programme helps predict how the atmosphere might change in the future.

"To members of the public it must seem like climate models are crystal balls, but they are actually just complex equations" says David Grinspoon, Denver Museum of Nature and Science, and one of Venus Express's interdisciplinary scientists.

The more scientists look at those equations, the more they realise just how complicated Earth's climate system is. Grinspoon puts the predicament like this: "In fifty or a hundred years, we will know whether today's climate models were right but if they are wrong, by then it will be too late."

To help increase confidence in the computer models, Grinspoon believes that scientists should look at our neighbouring planets. "It seems that both Mars and Venus started out much more like Earth and then changed. They both hold priceless climate information for Earth," says Grinspoon.

The atmosphere of Venus is much thicker than Earth's. Nevertheless, current climate models can reproduce its present temperature structure well. Now planetary scientists want to turn the clock back to understand why and how Venus changed from its former Earth-like conditions into the inferno of today.

They believe that the planet experienced a runaway greenhouse effect as the Sun gradually heated up. Astronomers believe that the young Sun was dimmer than the present-day Sun by 30 percent. Over the last 4 thousand million years, it has gradually brightened. During this increase, Venus's surface water evaporated and entered the atmosphere.

"Water vapour is a powerful greenhouse gas and it caused the planet to heat-up even more. This is turn caused more water to evaporate and led to a powerful positive feedback response known as the runaway greenhouse effect," says Grinspoon.

As Earth warms in response to manmade pollution, it risks the same fate. Reconstructing the climate of the past on Venus can give scientists a better understanding of how close our planet is to such a catastrophe. However, determining when Venus passed the point of no return is not easy. That's where ESA's Venus Express comes in.

The spacecraft is in orbit around Venus collecting data that will help unlock the planet's past. Venus is losing gas from its atmosphere, so Venus Express is measuring the rate of this loss and the composition of the gas being lost. It also watches the movement of clouds in the planet's atmosphere. This reveals the way Venus responds to the absorption of sunlight, because the energy from the Sun provides the power that allows the atmosphere to move.

In addition, Venus Express is charting the amount and location of sulphur dioxide in the planet's atmosphere. Sulphur dioxide is a greenhouse gas and is released by volcanoes on Venus.

"Understanding all of this will help us pin down when Venus lost its water," says Grinspoon. That knowledge can feed into the interpretation of climate models on the Earth because although both planets seem very different now, the same laws of physics govern both worlds.

Understanding Mars' past is equally important. ESA's Mars Express is currently investigating the fate of the Red Planet. Smaller than the Earth, Mars is thought to have lost its atmosphere to space. When Martian volcanoes became extinct, so did the planet's means of replenishing its atmosphere turning it into an almost-airless desert.

"What happened on these two worlds is very different but either would be equally disastrous for Earth. We are banking on our ability to accurately predict Earth's future climate," says Grinspoon. Anything that can shed light on our own future is valuable. That is why the study of our neighbouring worlds is vital.

So, when planetary scientists talk of exploring other worlds, they are also increasing their ability to understand our own planet.

Fish oil may help kidney disease sufferers

Fish oil may help kidney disease sufferers

Fish oil, it's been touted as an answer to Alzheimers, arthritis and even weight-loss but now a Queensland University of Technology researcher will test its health benefits in people with chronic kidney disease.

Dietitian Rachel Zabel, from QUT's Institute of Health and Biomedical Innovation, will investigate the effects of fish oil on patients with kidney disease undergoing dialysis.

Ms Zabel said daily doses of fish oil in the form of a tablet or liquid had been shown to decrease inflammation - a common problem in people with kidney disease.

"Research shows that patients with kidney disease on dialysis experience a range of complications thought to relate to chronic inflammation," she said.

"They can have poor nutritional status, disturbed appetite and a lower quality of life."

Ms Zabel said fish oils had known anti-inflammatory properties due to their high concentration of Eicosapentaenoic Acid (EPA).

"EPA has been used successfully in other population groups with chronic inflammation including people with osteoarthritis and cancer cachexia, however the anti-inflammatory effects have not yet been applied to patients on dialysis," she said.

As part of Ms Zabel's study, participants will be given a daily dose of fish oil, and tests will be conducted to measure changes in inflammation and appetite.

The 12-week study will seek to determine the success of fish oil as a treatment option for inflammation in people with chronic kidney disease.

Ms Zabel said, with one in three people in Australia at risk of developing chronic kidney disease, improving the quality of life for sufferers was essential.

"The incidence of chronic kidney disease is increasing," she said.

"One in seven people over the age of 25 have at least one clinical sign of chronic kidney disease and every day five Australians commence dialysis or transplantation to stay alive.

"While fish oil won't cure kidney disease, it may provide a better quality of life for sufferers."

The study is being conducted in collaboration with the Wesley Hospital.

Ice Retreating Faster Than Computer Models Project

Ice Retreating Faster Than Computer Models Project

Arctic sea ice is melting at a significantly faster rate than projected by even the most advanced computer models, a new study concludes. The research, by scientists at the National Center for Atmospheric Research (NCAR) and the University of Colorado's National Snow and Ice Data Center (NSIDC), shows that the Arctic's ice cover is retreating more rapidly than estimated by any of the 18 computer models used by the Intergovernmental Panel on Climate Change (IPCC) in preparing its 2007 assessments.

The study, "Arctic Sea Ice Decline: Faster Than Forecast?" will appear tomorrow in the online edition of Geophysical Research Letters. It was led by Julienne Stroeve of the NSIDC and funded by the National Science Foundation, which is NCAR's principal sponsor, and by NASA.

"While the ice is disappearing faster than the computer models indicate, both observations and the models point in the same direction: the Arctic is losing ice at an increasingly rapid pace and the impact of greenhouse gases is growing," says NCAR scientist Marika Holland, one of the study's co-authors.

The authors compared model simulations of past climate with observations by satellites and other instruments. They found that, on average, the models simulated a loss in September ice cover of 2.5 percent per decade from 1953 to 2006. The fastest rate of September retreat in any individual model was 5.4 percent per decade. (September marks the yearly minimum of sea ice in the Arctic.) But newly available data sets, blending early aircraft and ship reports with more recent satellite measurements that are considered more reliable than the earlier records, show that the September ice actually declined at a rate of about 7.8 percent per decade during the 1953-2006 period.

"This suggests that current model projections may in fact provide a conservative estimate of future Arctic change, and that the summer Arctic sea ice may disappear considerably earlier than IPCC projections," says Stroeve.

Thirty years ahead of schedule

The study indicates that, because of the disparity between the computer models and actual observations, the shrinking of summertime ice is about 30 years ahead of the climate model projections. As a result, the Arctic could be seasonally free of sea ice earlier than the IPCC- projected timeframe of any time from 2050 to well beyond 2100.

The authors speculate that the computer models may fail to capture the full impact of increased carbon dioxide and other greenhouse gases in the atmosphere. Whereas the models indicate that about half of the ice loss from 1979 to 2006 was due to increased greenhouse gases, and the other half due to natural variations in the climate system, the new study indicates that greenhouse gases may be playing a significantly greater role.

There are a number of factors that may lead to the low rates of simulated sea ice loss. Several models overestimate the thickness of the present-day sea ice and the models may also fail to fully capture changes in atmospheric and oceanic circulation that transport heat to polar regions.

March ice

Although the loss of ice for March is far less dramatic than the September loss, the models underestimate it by a wide margin as well. The study concludes that the actual rate of sea ice loss in March, which averaged about 1.8 percent per decade in the 1953 -2006 period, was three times larger than the mean from the computer models. March is typically the month when Arctic sea ice is at its most extensive.

The Arctic is especially sensitive to climate change partly because regions of sea ice, which reflect sunlight back into space and provide a cooling impact, are disappearing. In contrast, darker areas of open water, which are expanding, absorb sunlight and increase temperatures. This feedback loop has played a role in the increasingly rapid loss of ice in recent years, which accelerated to 9.1 percent per decade from 1979 to 2006 according to satellite observations.

Walt Meier, Ted Scambos, and Mark Serreze, all at NSIDC, also co-authored the study.

NCAR