Buckyballs enhance carbon capture

A press release from Rice University: Rice University scientists have discovered an environmentally friendly carbon-capture method that could be equally adept at drawing carbon dioxide emissions from industrial flue gases and natural gas wells.

The Rice lab of chemist Andrew Barron revealed in a proof-of-concept study that amine-rich compounds are highly effective at capturing the greenhouse gas when combined with carbon-60 molecules. The research is the subject of an open-access paper today in Nature’s online journal Scientific Reports.

“We had two goals,” Barron said. “One was to make the compound 100 percent selective between carbon dioxide and methane at any pressure and temperature. The other was to reduce the high temperature needed by other amine solutions to get the carbon dioxide back out again. We’ve been successful on both counts.”

Tests from one to 50 atmospheric pressures showed the Rice compound captured a fifth of its weight in carbon dioxide but no measurable amount of methane, Barron said, and the material did not degrade over many absorption/desorption cycles.

Carbon-60, the soccer ball-shaped molecule also known as buckminsterfullerene (or the “buckyball”) was discovered at Rice by Nobel Prize laureates Richard Smalley, Robert Curl and Harold Kroto in 1985. The ultimate curvature of buckyballs may make them the best possible way to bind amine molecules that capture carbon dioxide but allow desirable methane to pass through.

The Rice lab used buckyballs as crosslinkers between amines, nitrogen-based molecules drawn from polyethyleneimine. The lab produced a brown, spongy material in which hydrophobic (water-avoiding) buckyballs forced the hydrophilic (water-seeking) amines to the outside, where passing carbon dioxide could bind to the exposed nitrogen.

When Barron and his team began combining carbons and amines several years ago, they noticed an interesting progression: Flat graphene absorbed carbon dioxide well, multiwalled nanotubes absorbed it better, and thinner single-walled nanotubes even better. “That suggested the curvature was important,” Barron said. “C-60, being a sphere, has the highest possible curvature among carbon materials.”...

Carbon-60 molecules, also known as buckyballs, were combined with amines in a compound that absorbs a fifth of its weight in carbon dioxide. It shows potential as an environmentally friendly material for capturing carbon from natural gas wells and industrial plants. (Courtesy of the Barron Research Group/Rice University)

Recycling industrial waste water

Space Daily via SPX: A research group composed of Dr. Martin Prechtl, Leo Heim and their colleagues at the University of Cologne's Department of Chemistry has discovered a new method of generating hydrogen using water and formaldehyde.

The generation of hydrogen from liquids is of particular interest when it comes to fuel cell technologies. The results of the project, entitled "Selective and mild hydrogen production using water and formaldehyde", have recently been published in the journal Nature Communications.

Among other applications, the new approach can be used to recycle industrial waste water contaminated by formaldehyde to break down the contaminants whilst simultaneously generating hydrogen.

With the aid of this method, it is possible to reclaim an important raw material from industrial waste water. Prechtl and his colleagues have also identified an air-stable and robust catalyst that can be employed with the technique. The researchers have already filed a corresponding patent application....

A water treatment plant at Bret Lake, Switzerland, shot by Rama, Wikimedia Commons,  under the Creative Commons Attribution-Share Alike 2.0 France license

New long-lived greenhouse gas discovered

A press release from the University of Toronto media room: Scientists from U of T’s Department of Chemistry have discovered a novel chemical lurking in the atmosphere that appears to be a long-lived greenhouse gas (LLGHG).  The chemical – perfluorotributylamine (PFTBA) – is the most radiatively efficient chemical found to date, breaking all other chemical records for its potential to impact climate.

Radiative efficiency describes how effectively a molecule can affect climate. This value is then multiplied by its atmospheric concentration to determine the total climate impact.

PFTBA has been in use since the mid-20th century for various applications in electrical equipment and is currently used in thermally and chemically stable liquids marketed for use in electronic testing and as heat transfer agents.  It does not occur naturally, that is, it is produced by humans. There are no known processes that would destroy or remove PFTBA in the lower atmosphere so it has a very long lifetime, possibly hundreds of years, and is destroyed in the upper atmosphere.

“Global warming potential is a metric used to compare the cumulative effects of different greenhouse gases on climate over a specified time period,” said Cora Young who was part of the U of T team, along with Angela Hong and their supervisor, Scott Mabury.  Time is incorporated in the global warming potential metric as different compounds stay in the atmosphere for different lengths of time, which determines how long-lasting the climate impacts are.

Carbon dioxide (CO2) is used as the baseline for comparison since it is the most important greenhouse gas responsible for human-induced climate change.  “PFTBA is extremely long-lived in the atmosphere and it has a very high radiative efficiency; the result of this is a very high global warming potential. Calculated over a 100-year timeframe, a single molecule of PFTBA has the equivalent climate impact as 7100 molecules of CO2,” said Hong....

Smokestacks in Champaign, Illinois, shot by Dori, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 United States license

Two thirds of eastern US rivers are alkaline

Futurity: Human activities are changing the basic chemistry of rivers in ways that could have major consequences for urban water supplies and aquatic ecosystems.

In the first survey of its kind, researchers looked at long-term records of alkalinity trends in 97 rivers from Florida to New Hampshire. They found that over time spans of 25 to 60 years, two-thirds of the rivers had become significantly more alkaline.

Increased alkalinity complicates drinking water and wastewater treatment, encourages algae growth, and can hasten the corrosion of metal pipe infrastructure. At high alkalinity levels, ammonia toxicity can also harm irrigated crops and fish in rivers.

 “The change across so many larger rivers of the eastern U.S. is a big surprise,” says study co-author Michael Pace, an environmental scientist in the University of Virginia.

Among the rivers affected are those that provide water for Washington, DC, Philadelphia, Baltimore, Atlanta, and other major cities, the researchers report. Also affected are rivers that flow into water bodies already harmed by excess algae growth, such as the Chesapeake Bay....

Susquehanna River at sundown, shot by fishhawk, Wikimedia Commons via Flickr,  under the Creative Commons Attribution 2.0 Generic license

Improving crop yields in a world of extreme weather events

Iqbal Pittalwala in UC Riverside News: Farmers in the United States witnessed record-breaking extremes in temperature and drought during the last two summers, causing worldwide increases in the costs of food, feed and fiber.  Indeed, many climate scientists caution that extreme weather events resulting from climate change is the new normal for farmers in North America and elsewhere, requiring novel agricultural strategies to prevent crop losses. Now a research team led by Sean Cutler, a plant cell biologist at the University of California, Riverside, has found a new drought-protecting chemical that shows high potential for becoming a powerful tool for crop protection in the new world of extreme weather.

Named “quinabactin” by the researchers, the chemical mimics a naturally occurring stress hormone in plants that helps the plants cope with drought conditions. Study results appear online this week in the Proceedings of the National Academy of Sciences.

All land plants have intricate water sensing and drought response systems that are tuned to maximize their fitness in the environments they live in. For example, plants in environments with low water grow slowly so that they do not consume more water than is available. “But since farmers have always desired fast-growing varieties, their most valued strains did not always originate from drought-tolerant progenitors,” explained Cutler, an associate professor of plant cell biology. “As a result, we have crops today that perform very well in years of plentiful water but poorly in years with little water. This dilemma has spawned an active hunt for both new drought-tolerant crops and chemicals that farmers might use for improving crop yield under adverse conditions.”

Working on Arabidopsis, a model plant used widely in plant biology labs, Cutler and his colleagues focused their efforts on tinkering with one of the plant endogenous systems involved in drought responses.  Plant leaves are lined with tiny pores, called stomata, which dynamically open and close to control the amount of water lost to the environment by evaporation. So that the plants can acquire carbon dioxide from the atmosphere, the pores need to be open some of the time, resulting in some loss of water.

...To address this problem, Cutler and his team searched through many thousands of molecules to identify inexpensive synthetic chemicals that could activate the receptors by mimicking ABA. The team found and named quinabactin, a molecule they show is almost indistinguishable from ABA in its effects, but much simpler chemically and therefore easier to make than ABA. By studying how the new molecule activates the ABA receptors that are involved in drought tolerance, the team also has learned more about the underlying control logic of the stress response system and provided new information that can be used for others interested in developing similar molecules.

“This is a competitive arena that includes agrichemical giants who are busily working to bring similar drought-protecting molecules to market, so this is a landmark discovery because quinabactin is the first-in-class synthetic molecule of its kind,” Cutler said....

The image shows quinabactin (in color) docked inside its receptor protein (in gray). IMAGE CREDIT: CUTLER LAB, UC RIVERSIDE.

The contribution of particulate matter to forest decline

Bonn University: Air pollution is related to forest decline and also appears to attack the protecting wax on tree leaves and needles. Bonn University scientists have now discovered a responsible mechanism: particulate matter salt compounds that become deliquescent because of humidity and form a wick-like structure that removes water from leaves and promotes dehydration. These results are published in “Environmental Pollution”.

Nature conservationists call it “lingering illness”, and the latest report on the North-Rhine Westphalian forest conditions confirms ongoing damage. Bonn University scientists have now shown that salt deposits on leaves may decrease the drought tolerance of trees, thereby contributing to forest decline. “Our study reveals that so-called wax degradation on pine needles may develop from deposited particulate matter”, says Dr. Jürgen Burkhardt from the Institute of Crop Science and Resource Conservation. Wax helps to protect leaves and needles from water loss.

It has long been known that air pollutants accelerate wax ageing and that “wax degradation” is closely related to forest damage. “Wax degradation was addressed by many studies in the 1980s and 90s, but sound explanations for both the degradation mechanism and the high correlation with forest damage have yet been missing”, Dr. Burkhardt reports. Previous approaches assumed chemical reactions for wax degradation, whereas the present study reveals physical reasons. “The deposition of hygroscopic salts is capable of decreasing the drought tolerance of trees”, co-author Shyam Pariyar says.

...Recently, regional forest damage has been reported in the western USA and other parts of the world. A relationship with increasing climate change-type drought has been proposed, but the newly discovered mechanism involving particulate matter might contribute to the regional forest damage. “Particularly because air concentrations of hygroscopic particles have largely increased within the last decades”, says Dr. Burkhardt...

A foggy forest near the northern Rhine, shot by Thomas Klein-Hitpaß (Rototom), Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Toxic waste sites cause healthy years of life lost

Terra Daily via SPX: Toxic waste sites with elevated levels of lead and chromium cause a high number of "healthy years of life lost" in individuals living near 373 sites located in India, Philippines and Indonesia, according to a study by a Mount Sinai researcher published online in Environmental Health Perspectives.

The study leader, Kevin Chatham-Stephens, MD, Pediatric Environmental Health Fellow at the Icahn School of Medicine at Mount Sinai, presented the findings at the Pediatric Academic Societies (PAS) annual meeting in Washington, DC.

"Lead and hexavalent chromium proved to be the most toxic chemicals and caused the majority of disease, disability and mortality among the individuals living near the sites," said Dr. Chatham-Stephens, first author. The study titled, "The Burden of Disease from Toxic Waste Sites in India, Indonesia, and the Philippines in 2010," was a joint research partnership between Mount Sinai and the Blacksmith Institute.

Eight chemicals were sampled and collected at the toxic waste sites in 2010. The samples were then measured for pollutant levels in the soil and water and then compared with the 8,629,750 individuals who were at risk of exposure around these sites in order to calculate the loss of years of equivalent full health.

Researchers calculated healthy years of life lost due to ill-health, disability or early death, in disability-adjusted life years (DALY), a measure of overall disease burden used by the World Health Organization. One DALY represents the loss of one year of equivalent full health. In this study, the total number of lost years of full health or DALYs was 828,722....

A lead bead, shot by Jurii, Wikimedia Commons, under the Creative Commons Attribution 3.0 Unported license

New Fischer-Tropsch catalyst invented in Amsterdam

University of Amsterdam News: Inspired by patents from the 1960’s audio cassette recording industry, UvA chemists now developed a new Fischer-Tropsch catalyst. It can be used for the making of synthetic fuels from natural gas and biomass. This week the research on the new nanocobalt-ironoxide catalyst was published as a VIP article in Angewandte Chemie. The catalyst was patented by the Total S.A. oil and gas company.

Roberto Calderone, Raveendran Shiju and Gadi Rothenberg from the Heterogeneous Catalysis and Sustainable Chemistry group (Van ‘t Hoff Institute for Molecular Sciences) succeeded in growing nanometer-thin cobalt shells on iron oxide particles. These new materials are excellent Fischer-Tropsch (F-T) catalysts, giving good diesel fractions.

The Fischer-Tropsch process is used for producing fuels from synthesis gas, which in turn is made from natural gas, biomass or coal. The large reserves of shale gas and natural gas currently changing the world energy market have raised interest in F-T technology. But there is a catch: F-T reactors are huge, and typically use hundreds of tons of catalyst.

Cobalt-based catalysts are the optimal choice for synthesizing middle distillate fuels such as diesel and kerosene with F-T technology. But cobalt is also expensive. In 2009 the Total Gaz & Power company contacted Rothenberg’s group to develop a new F-T catalyst together. The UvA researchers took up the challenge to design a cheaper catalyst that can be prepared on a very large scale, yet performs at least as well as pure cobalt.

The UvA team sought to meet these restraints with the so-called surface nucleation of a cobalt phase onto iron oxide colloids. They were inspired by the method that companies such as TDK used in the 1960s for producing magnetic tapes for audio cassettes. The standard recording materials in these cassettes were polymer-based tapes containing cigar-shaped cobalt-doped iron oxide particles.

After two years of hard work they achieved a cheap, reliable, efficient and, most importantly, scalable method for synthesizing spherical core-shell catalyst particles. The particles have an average diameter of 10 nanometer (nm) and consist of a 8 nm magnetite (iron oxide) core with a cobalt oxide shell of only 1 nm. The new catalysts were then tested in collaboration with research groups of Andreas Jess in Bayreuth and Andrei Khodakov in Lille. They proved to be excellent Fischer-Tropsch catalysts, giving good diesel fractions....

Link found between climate change, ozone loss and possible increase in skin cancer incidence

EurekAlert: For decades, scientists have known that the effects of global climate change could have a potentially devastating impact across the globe, but Harvard researchers say there is now evidence that it may also have a dramatic impact on public health.

As reported in a paper published in the July 27 issue of Science, a team of researchers led by James G. Anderson, the Philip S. Weld Professor of Atmospheric Chemistry, are warning that a newly-discovered connection between climate change and depletion of the ozone layer over the U.S. could allow more damaging ultraviolet (UV) radiation to reach the Earth's surface, leading to increased incidence of skin cancer.

In the system described by Anderson and his team, water vapor injected into the stratosphere by powerful thunderstorms converts stable forms of chlorine and bromine into free radicals capable of transforming ozone molecules into oxygen. Recent studies have suggested that the number and intensity of such storms are linked to climate changes, Anderson said, which could in turn lead to increased ozone loss and greater levels of harmful UV radiation reaching the Earth's surface, and potentially higher rates of skin cancer.

"If you were to ask me where this fits into the spectrum of things I worry about, right now it's at the top of the list," Anderson said. "What this research does is connect, for the first time, climate change with ozone depletion, and ozone loss is directly tied to increases in skin cancer incidence, because more ultraviolet radiation is penetrating the atmosphere."...

Studying soil to predict the future of earth's atmosphere

Brigham Young University: When it comes to understanding climate change, it’s all about the dirt. A new study by researchers at BYU, Duke and the USDA finds that soil plays an important role in controlling the planet’s atmospheric future.

The researchers set out to find how intact ecosystems are responding to increased levels of carbon dioxide in the atmosphere. The earth’s current atmospheric carbon dioxide is 390 parts per million, up from 260 parts per million at the start of the industrial revolution, and will likely rise to more than 500 parts per million in the coming decades.

What they found, published in the current issue of Nature Climate Change, is that the interaction between plants and soils controls how ecosystems respond to rising levels of CO2 in the atmosphere. “As we forecast what the future is going to look like, with the way we’ve changed the global atmosphere, often times we overlook soil,” said BYU biology professor Richard Gill, a coauthor on the study. “The soils matter enormously and the feedbacks that occur in the soil are ultimately going to control the atmosphere.”

The research shows that even in the absence of climate change, humans are impacting vital ecosystems as the composition of the earth’s atmosphere changes. They observed that changes in atmospheric CO2 caused changes in plant species composition and the availability of water and nitrogen. Researchers worry that if the ability of plants and soils to absorb carbon becomes saturated over time then CO2 in the atmosphere will increase much more quickly than it has in the past.

“We don’t just have to be concerned about climate change, we have to be concerned about the other changes in atmospheric chemistry,” Gill said. “Globally we’re changing the earth’s atmosphere and we know that is going to influence the systems we depend on. To forecast those changes, you have to understand deeply what is happening in soils.”...

Undergraduate Sarah Karlinsey measures photosynthesis levels at a site near Ephraim, Utah. From the BYU website

Today’s environment influences behavior generations later

Eric Sorensen at Washington State University News: Researchers at The University of Texas at Austin and Washington State University have seen an increased reaction to stress in animals whose ancestors were exposed to an environmental compound generations earlier. The findings, published in the latest Proceedings of the National Academy of Sciences, put a new twist on the notions of nature and nurture, with broad implications for how certain behavioral tendencies might be inherited.

The researchers—David Crews at Texas , Michael Skinner at Washington State and colleagues—exposed gestating female rats to vinclozolin, a popular fruit and vegetable fungicide known to disrupt hormones and have effects across generations of animals. The researchers then put the rats’ third generation of offspring through a variety of behavioral tests and found they were more anxious, more sensitive to stress, and had greater activity in stress-related regions of the brain than descendants of unexposed rats.

"We are now in the third human generation since the start of the chemical revolution, since humans have been exposed to these kinds of toxins,” says Crews. "This is the animal model of that. The ancestral exposure of your great grandmother alters your brain development to then respond to stress differently,” says Skinner. "We did not know a stress response could be programmed by your ancestors’ environmental exposures.”

The researchers had already shown exposure to vinclozolin can effect subsequent generations by affecting how genes are turned on and off, a process called epigenetics. In that case, the epigenetic transgenerational inheritance altered how rats choose mates....

An illustration of the interrelation between genetics and epigenentics (drawn from cancer research, but the idea is similar), from the National Institutes of Health

Bark beetle may affect air quality, climate

Tim Crosby in the Saluki Times at Southern Illinois University at Carbondale: If you’ve traveled to a forested national park out West in recent years, you may have noticed two things. First, a growing number of lodgepole pine trees are dying, victims of the bark beetle.  And secondly, atmospheric haze, caused in part by tiny solid particles suspended in the air, is becoming a problem.

A study by a researcher at Southern Illinois University Carbondale shows these two phenomena may be related, tied together by chemistry and climate change factors. Kara Huff Hartz, assistant professor of chemistry and biochemistry in the College of Science, has authored a study appearing today (May 23) in the journal Environmental Science & Technology, a division of the American Chemical Society. The study, which Huff Hartz conducted by collecting gas specimens from bark beetle-infested and non-infested lodgepole pines, shows a large increase in the gases given off by the beetle infestations, which could enhance airborne particulate matter problems and haze in the area.

The findings will bring better understanding to atmospheric maladies such as particulate matter, which can cause health problems in the very young and old, as well as other problems. It also may provide a window into understanding the links between climate change and environmental inputs such as volatile organic compounds (VOCs), which come from both natural and anthropogenic sources.

...Airborne particulate matter is a well-known health hazard that involves solids smaller in diameter than a human hair suspended in the atmosphere where they can be inhaled. Depending on the type, concentration and location, particulate matter can also impact climate by causing haze, preventing rain or leading to cooling, Huff Hartz said....

A bark beetle gallery in a pine tree, shot by L. Shyamal, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 2.5 Generic license

Exploring the chemistry of thunderstorms

NASA: NASA researchers are about to fly off on a campaign that will take them into the heart of thunderstorm country. The Deep Convective Clouds and Chemistry (DC3) field campaign will use an airport in Salina, Kan., as a base to explore the impact of large thunderstorms on the concentration of ozone and other substances in the upper troposphere. The campaign is being led by the National Center for Atmospheric Research in Boulder, Colorado, and is funded by the National Science Foundation (NSF) and NASA.

"Thunderstorms provide a mechanism for rapid lifting of air from the surface to higher altitudes in a matter of minutes to hours," said James Crawford of NASA's Langley Research Center in Hampton, Va., and a member of the mission's scientific steering committee. "This allows molecules that are short-lived and more abundant near the surface to be transported to the upper troposphere in amounts that could not happen under normal atmospheric conditions," he said.

Additional chemical impacts come from the production of nitrogen oxides by lightning, but the details of these processes are not well understood.

"All of this together has an influence on ozone in the coldest part of the atmosphere where it exerts the largest influence on climate," Crawford said. "Of the chemicals we'll be studying, nitrogen oxides in particular are key to the creation of ozone and are produced both naturally by lightning and by human activity through the burning of fossil fuels."

The campaign is scheduled to run from May 15 to June 30. NASA partners include Langley, Goddard Space Flight Center in Greenbelt, Md., Marshall Space Flight Center in Huntsville, Ala., Ames Research Center at Moffett Field, Calif. and Dryden Flight Research Center in Edwards, Calif...

A thunderstorm shot by Rolf van Melis (RvM), Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Ocean acidification linked to larval oyster failure

Oregon State University: Researchers at Oregon State University have definitively linked an increase in ocean acidification to the collapse of oyster seed production at a commercial oyster hatchery in Oregon, where larval growth had declined to a level considered by the owners to be “non-economically viable.”

A study by the researchers found that elevated seawater carbon dioxide (CO2) levels, resulting in more corrosive ocean water, inhibited the larval oysters from developing their shells and growing at a pace that would make commercial production cost-effective. As atmospheric CO2 levels continue to rise, this may serve as the proverbial canary in the coal mine for other ocean acidification impacts on shellfish, the scientists say. Results of the research have just been published in the journal, Limnology and Oceanography.

“This is one of the first times that we have been able to show how ocean acidification affects oyster larval development at a critical life stage,” said Burke Hales, an OSU chemical oceanographer and co-author on the study. “The predicted rise of atmospheric CO2 in the next two to three decades may push oyster larval growth past the break-even point in terms of production.”

....“The early growth stage for oysters is particularly sensitive to the carbonate chemistry of the water,” said George Waldbusser, a benthic ecologist in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “As the water becomes more acidified, it affects the formation of calcium carbonate, the mineral of which the shell material consists. As the CO2 goes up, the mineral stability goes down, ultimately leading to reduced growth or mortality.”...

Pacific oysters, shot by David Monniaux and modified by Peter Gugerell, Wikimedia Commons, under the Creative Commons Attribution 2.5 Generic license

NASA finds sea ice driving arctic air pollutants

NASA: Drastic reductions in Arctic sea ice in the last decade may be intensifying the chemical release of bromine into the atmosphere, resulting in ground-level ozone depletion and the deposit of toxic mercury in the Arctic, according to a new NASA-led study.

The connection between changes in the Arctic Ocean's ice cover and bromine chemical processes is determined by the interaction between the salt in sea ice, frigid temperatures and sunlight. When these mix, the salty ice releases bromine into the air and starts a cascade of chemical reactions called a "bromine explosion." These reactions rapidly create more molecules of bromine monoxide in the atmosphere. Bromine then reacts with a gaseous form of mercury, turning it into a pollutant that falls to Earth's surface.

Bromine also can remove ozone from the lowest layer of the atmosphere, the troposphere. Despite ozone's beneficial role blocking harmful radiation in the stratosphere, ozone is a pollutant in the ground-level troposphere.

A team from the United States, Canada, Germany, and the United Kingdom, led by Son Nghiem of NASA's Jet Propulsion Laboratory in Pasadena, Calif., produced the study, which has been accepted for publication in the Journal of Geophysical Research- Atmospheres. The team combined data from six NASA, European Space Agency and Canadian Space Agency satellites; field observations and a model of how air moves in the atmosphere to link Arctic sea ice changes to bromine explosions over the Beaufort Sea, extending to the Amundsen Gulf in the Canadian Arctic.

"Shrinking summer sea ice has drawn much attention to exploiting Arctic resources and improving maritime trading routes," Nghiem said. "But the change in sea ice composition also has impacts on the environment. Changing conditions in the Arctic might increase bromine explosions in the future."...

Bromine explosion on March 13, 2008 across the western Northwest Territories in Canada looking toward the Mackenzie Mountains at the horizon, which prevented the bromine from crossing over into Alaska. The bromine explosion is depicted in the foreground by the red-orange areas, while the green shades at high altitudes on the mountains represent areas where there was no increase in bromine. Image credit: NASA/JPL-Caltech/University of Bremen

Ocean acidification on track to be among the worst of the last 300 million years

Scott K. Johnson in Ars Technica: Some like to point to cycles when dismissing climate change, brushing off warming as simply being the thing that happens right before cooling. In this view, concern about climate change is akin to the naïve worry that half of schools are performing below average. This is why we need context. We need to know whether an observed change is more like a world premiere or a familiar re-run.

A new paper in Science examines the geologic record for context relating to ocean acidification, a lowering of the pH driven by the increased concentration of carbon dioxide in the atmosphere. The research group (twenty-one scientists from nearly as many different universities) reviewed the evidence from past known or suspected intervals of ocean acidification. The work provides perspective on the current trend as well as the potential consequences. They find that the current rate of ocean acidification puts us on a track that, if continued, would likely be unprecedented in last 300 million years.

...While the authors frequently point out the difficulty in teasing apart the effects of ocean acidification and climate change, they argue that this is really an academic exercise. It’s more useful to consider the witches’ brew with all the ingredients—acidification, temperature change, and changes in dissolved oxygen—since, historically, those have come together. That combination produces unequivocally bad news.

The authors conclude, “[T]he current rate of (mainly fossil fuel) CO2 release stands out as capable of driving a combination and magnitude of ocean geochemical changes potentially unparalleled in at least the last ~300 [million years] of Earth history, raising the possibility that we are entering an unknown territory of marine ecosystem change.”

From 2007: Estimated change in sea surface pH from the pre-industrial period (1700s) to the present day (1990s). Δ pH here is in standard pH units. This change is caused by the invasion of anthropogenic CO2 (see Ocean acidification). Image by Plumbago, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Protecting the climate by reducing fluorinated greenhouse gas emissions

EMPA, a research institute of the ETH (Zurich): The Montreal Protocol led to a global phase-out of most substances that deplete the ozone layer, such as chlorofluorocarbons (CFCs). A happy side-effect of the gradual ban of these products is that the Earth’s climate has also benefited because CFCs are also potent greenhouse gases.

However, now a "rebound effect" threatens to accelerate the rate of global warming. Hydrofluorocarbons (HFCs), which have been used in recent years in increasing quantities as substitutes for CFCs, are also climatically very active and many are also extremely long-lived. In the renowned journal Science an international team of researchers recommends that the most potent of these gases also be regulated. This could save the positive side effect of the Montreal Protocol for the global climate.

.... Since the year 2000 the radiative forcing (a measure of the effect on the climate of chemical substances) of all ozone-depleting substances including CFCs has remained at a more or less constant value of 0.32 W/m2, compared to a value of 1.5 W/m2 for CO2. Had the Montreal Protocol recommendations not been implemented, today’s value would be approximately double this figure, i.e. 0.65 W/m2. Putting things another way, the CFC ban has prevented the equivalent of 10 billion tonnes of CO2 being emitted into the atmosphere in 2010, five times the annual reduction target set by the Kyoto Protocol.

Velders, Reimann and their co-authors fear that this positive effect will soon be negated by HFC emissions, which are currently increasing at 10 to 15% annually. n their article they state that «the HFC contribution to climate change can be viewed as an unintended negative side effect» of the Montreal Protocol. At the moment the effect is still small – about 0.012 W/m2 for all CFC substitutes combined. But it is beyond question that radiative forcing due to HFCs will rise significantly in future as a result of increasing demand and production for these substances, above all in threshold and developing countries. The atmospheric scientists estimate that this value will rise to between 0.25 und 0.4 W/m2 by the year 2050. The greatest problem is presented by saturated HFCs, which are extremely stable and survive in the atmosphere for up to 50 years, exhibiting a long-term global warming potential of up to 4000 times higher than CO2. For Empa researcher Reimann the situation is clear: "Long-lived HFCs should no longer be used in these quantities."...

Space-filling model of the 2,3,3,3-tetrafluoropropene molecule, a hydrofluorocarbon used as a refrigerant, created by Ephemeronium, public domain

Peatland carbon storage is stabilized against catastrophic release of carbon

American Chemical Society: Concerns that global warming may have a domino effect —unleashing 600 billion tons of carbon in vast expanses of peat in the Northern hemisphere and accelerating warming to disastrous proportions — may be less justified than previously thought. That’s the conclusion of a new study on the topic in ACS’ journal Environmental Science & Technology.

Christian Blodau and colleagues explain that peat bogs — wet deposits of partially decayed plants that are the source of gardeners’ peat moss and fuel — hold about one-third of the world’s carbon. Scientists have been concerned that global warming might dry out the surface of peatlands, allowing the release into the atmosphere of carbon dioxide and methane (a greenhouse gas even more potent than carbon dioxide) produced from decaying organic matter. To see whether this catastrophic domino effect is a realistic possibility, the scientists conducted laboratory simulations studying the decomposition of wet bog peat for nearly two years.

Far from observing sudden releases of greenhouse gases, they found that carbon release and methane production slowed down considerably in deeply buried wet peat, most likely because deeper peat is shielded from exchange of water and gases with the atmosphere. In connection with previous work, the study concluded that “even under moderately changing climatic conditions,” peatlands will continue to sequester, or isolate from the atmosphere, their huge deposits of carbon and methane....

Peat exploitation in the nature conservation area (!) of "Ewiges Meer" ("Eternal lake"), a big moor lake in East Frisia, NW Germany. Shot by Christian Fischer, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

The first true view of global erosion

Joshua E. Brown in the University of Vermont News talks about a cool method for measuring erosion. I always knew that someone would find a use for beryllium-10!: ...For more than a century, scientists have looked for ways to measure and compare erosion rates across differing landscapes around the globe—but with limited success. “Knowing the background rate of erosion for a place is extremely important,” says University of Vermont geologist Paul Bierman, “if you want to compare it to what’s coming off the landscape today because of human impacts like agriculture, development, and forestry.”

Since the mid-1980’s, measurements of a rare radioactive element—beryllium-10 that appears in quartz bombarded by cosmic rays in the top few feet of Earth’s surface—have greatly improved geologists’ ability to estimate erosion rates. But these experiments have been done on a local or regional scale, using a variety of methods, calculation constants, and corrections. Comparisons between climate zones and differing rock types have been difficult—cutting off a global perspective.

Now Bierman and his graduate student, Eric Portenga, have taken twenty years worth of this disparate data, compiled 1599 measurements from eighty-seven sites around the world, and recalculated it with a single, up-to-date method. Their work, “provides the first broad, standardized view of pre-human, geologic erosion rates,” they write in “Understanding Earth’s eroding surface with 10Be,” published in the August edition of GSA Today, an open-access journal, available online July 26, 2011.

...The method used in this new study can provide a good tool for measuring the sustainability of modern agricultural practices, Bierman notes, since the beryllium-10 data shows the rate at which landscapes have been changing in the recent geologic past: the last thousand to several-hundred-thousand years. “If human impacts result in rates faster than we measure, it’s non-sustainable,” he says.

...“Following this study, we can start to answer big questions like, ‘how does climate drive erosion?’” says Bierman. In other words, a clearer picture of what global erosion has looked like in the recent past will start to illuminate what is likely to happen in the future as human impacts and land-use decisions play out...

The Delicate Arch in Arches National Park, Utah, National Park Service

NASA work helps better predict world's smoggiest days

Terra Daily: A research team led by NASA's Jet Propulsion Laboratory and the California Institute of Technology (Caltech), both in Pasadena, Calif., has fully characterized a key chemical reaction that affects the formation of pollutants in smoggy air in the world's urban areas. When applied to Los Angeles, the laboratory results suggest that, on the most polluted days and in the most polluted parts of L.A., current models are underestimating ozone levels by 5 to 10 percent.

The results-published this week in the journal Science-are likely to have "a small but significant impact on the predictions of computer models used to assess air quality, regulate emissions and estimate the health impact of air pollution," said Mitchio Okumura, professor of chemical physics at Caltech and one of the principal investigators on the research. "This work demonstrates how important accurate laboratory measurements are to our understanding of the atmosphere," said JPL senior research scientist Stanley P. Sander, who led the JPL team's effort. "This is the first time this crucial chemical reaction has been studied by two teams using complementary methods that allow its details to be understood."

The key reaction in question in this research is between nitrogen dioxide and the hydroxyl radical. In the presence of sunlight, these two compounds, along with volatile organic compounds, play important roles in the chemical reactions that form ozone, which at ground-level is an air pollutant harmful to plants and animals, including humans.

Until about the last decade, scientists thought these two compounds only combined to form nitric acid, a fairly stable molecule with a long atmospheric life that slows ozone formation.

Chemists suspected a second reaction might also occur, creating peroxynitrous acid, a less stable compound that falls apart quickly once created, releasing the hydroxyl radical and nitrogen dioxide to resume ozone creation.

But until now they weren't sure how quickly these reactions occur and how much nitric acid they create relative to peroxynitrous acid. The JPL team measured this rate using a high-accuracy, JPL-built, advanced chemical reactor. The Caltech team then determined the ratio of the rates of the two separate processes….

Smog masks in Los Angeles