Microscopic organism plays a big role in ocean carbon cycling

It’s broadly understood that the world’s oceans play a crucial role in the global-scale cycling and exchange of carbon between Earth’s ecosystems and atmosphere. Now scientists at Scripps Institution of Oceanography at UC San Diego have taken a leap forward in understanding the microscopic underpinnings of these processes.When phytoplankton use carbon dioxide to make new cells, a substantial portion of that cellular material is released into the sea as a buffet of edible molecules collectively called “dissolved organic carbon.” The majority of these molecules are eventually eaten by microscopic marine bacteria, used for energy, and recycled back into carbon dioxide as the bacteria exhale. The amount of carbon that remains as cell material determines the role that ocean biology plays in locking up atmospheric carbon dioxide in the ocean.Thus, these “recycling” bacteria play an important role in regulating how much of the planet’s carbon dioxide is stored in the oceans. The detailed mechanisms of how the oceans contribute to this global carbon cycle at the microscopic scale, and which microbes have a leadership role in the breakdown process, are complex and convoluted problems to solve.In a study published in the Proceedings of the National Academy of Sciences, Scripps scientists have pinpointed a bacterium that appears to play a dominant role in carbon consumption. Scripps’s Byron Pedler, Lihini Aluwihare, and Farooq Azam found that a single bacterium called Alteromonas could consume as much dissolved organic carbon as a diverse community of organisms.”This was a surprising result,” said Pedler. “Because this pool of carbon is composed of an extremely diverse set of molecules, we believed that many different microbes with complementary abilities would be required to breakdown this material, but it appears that individual species may be pulling more weight than others when it comes to carbon cycling.”Pedler, a marine biology graduate student at Scripps, spent several years working with Scripps marine microbiologist Azam and chemical oceanographer Aluwihare in designing a system that would precisely measure carbon consumption by individual bacterial species. Because carbon in organic matter is essentially all around us, the most challenging part of conducting these experiments is avoiding contamination.”Much of the carbon cycling in the ocean happens unseen to the naked eye, and it involves a complex mix of processes involving microbes and molecules,” said Azam, a distinguished professor of marine microbiology. “The complexity and challenge is not just that we can’t see it but that there’s an enormous number of different molecules involved. The consequences of these microbial interactions are critically important for the global carbon cycle, and for us.”By demonstrating that key individual species within the ecosystem can play a disproportionally large role in carbon cycling, this study helps bring us a step closer to understanding the function these microbes play in larger questions of climate warming and increased acidity in the ocean.”In order to predict how ecosystems will react when you heat up the planet or acidify the ocean, we first need to understand the mechanisms of everyday carbon cycling — who’s involved and how are they doing it?” said Pedler. “Now that we have this model organism that we know contributes to ocean carbon cycling, and a model experimental system to study the process, we can probe further to understand the biochemical and genetic requirements for the breakdown of this carbon pool in the ocean.”While the new finding exposes the unexpected capability of a significant species in carbon cycling, the scientists say there is much more to the story since whole communities of microbes may interact together or live symbiotically in the microscopic ecosystems of the sea.Pedler, Aluwihare, and Azam are now developing experiments to test other microbes and their individual abilities to consume carbon.The study was supported by the Gordon and Betty Moore Foundation Marine Microbiology Initiative through grant GBMF2758 and the National Science Foundation.Story Source:The above story is based on materials provided by University of California – San Diego. …

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Carbon loss from soil accelerating climate change

Research published in Science today found that increased levels of carbon dioxide in the atmosphere cause soil microbes to produce more carbon dioxide, accelerating climate change.Two Northern Arizona University researchers led the study, which challenges previous understanding about how carbon accumulates in soil. Increased levels of CO2 accelerate plant growth, which causes more absorption of CO2 through photosynthesis.Until now, the accepted belief was that carbon is then stored in wood and soil for a long time, slowing climate change. Yet this new research suggests that the extra carbon provides fuel to microorganisms in the soil whose byproducts (such as CO2) are released into the atmosphere, contributing to climate change.”Our findings mean that nature is not as efficient in slowing global warming as we previously thought,” said Kees Jan van Groenigen, research fellow at the Center for Ecosystem Science and Society at NAU and lead author of the study. “By overlooking this effect of increased CO2 on soil microbes, models used by the Intergovernmental Panel on Climate Change may have overestimated the potential of soil to store carbon and mitigate the greenhouse effect.”In order to better understand how soil microbes respond to the changing atmosphere, the study’s authors utilized statistical techniques that compare data to models and test for general patterns across studies. They analyzed published results from 53 different experiments in forests, grasslands and agricultural fields around the world. These experiments all measured how extra CO2 in the atmosphere affects plant growth, microbial production of carbon dioxide, and the total amount of soil carbon at the end of the experiment.”We’ve long thought soils to be a stable, safe place to store carbon, but our results show soil carbon is not as stable as we previously thought,” said Bruce Hungate, director of the Center for Ecosystem Science and Society at NAU and study author. “We should not be complacent about continued subsidies from nature in slowing climate change.”Story Source:The above story is based on materials provided by Northern Arizona University. Note: Materials may be edited for content and length.

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Amazon inhales more carbon than it emits, NASA finds

A new NASA-led study seven years in the making has confirmed that natural forests in the Amazon remove more carbon dioxide from the atmosphere than they emit, therefore reducing global warming. This finding resolves a long-standing debate about a key component of the overall carbon balance of the Amazon basin.The Amazon’s carbon balance is a matter of life and death: living trees take carbon dioxide out of the air as they grow, and dead trees put the greenhouse gas back into the air as they decompose. The new study, published in Nature Communications on March 18, is the first to measure tree deaths caused by natural processes throughout the Amazon forest, even in remote areas where no data have been collected at ground level.Fernando Esprito-Santo of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., lead author of the study, created new techniques to analyze satellite and other data. He found that each year, dead Amazonian trees emit an estimated 1.9 billion tons (1.7 billion metric tons) of carbon to the atmosphere. To compare this with Amazon carbon absorption, the researchers used censuses of forest growth and different modeling scenarios that accounted for uncertainties. In every scenario, carbon absorption by living trees outweighed emissions from the dead ones, indicating that the prevailing effect in natural forests of the Amazon is absorption.Until now, scientists had only been able to estimate the Amazon’s carbon balance from limited observations in small forest areas called plots. On these plots, the forest removes more carbon than it emits, but the scientific community has been vigorously debating how well the plots represent all the natural processes in the huge Amazon region. That debate began with the discovery in the 1990s that large areas of the forest can be killed off by intense storms in events called blowdowns.Esprito-Santo said that the idea for the study arose from a 2006 workshop where scientists from several nations came together to identify NASA satellite instruments that might help them better understand the carbon cycle of the Amazon. In the years since then, he worked with 21 coauthors in five nations to measure the carbon impacts of tree deaths in the Amazon from all natural causes — from large-area blowdowns to single trees that died of old age. He used airborne lidar data, satellite images, and a 10-year set of plot measurements collected by the University of Leeds, England, under the leadership of Emanuel Gloor and Oliver Phillips. …

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Study suggests non-uniform climate warming globally

A recent University of Oklahoma study of five decades of satellite data, model simulations and in situ observations suggests the impact of seasonal diurnal or daily warming varies between global regions affecting many ecosystem functions and services, such as food production, carbon sequestration and climate regulation. The effects of non-uniform climate warming on terrestrial ecosystems is a key challenge in carbon cycle research and for those making future predictions.Jianyang Xia, a research associate in the OU College of Arts and Sciences, says the impact of non-uniform warming is just one aspect of climate change. Shifts in precipitation and disturbances, such as wildfires, increases in the frequency of extreme temperature events, large year-to-year shifts in temperature and shifts in regional climate zones can be expected as the climate warms. A complete understanding of the consequences of climate change for carbon cycling on land requires insight into the impact of all these changes on the ecosystem.As this study suggests, the rate of climate warming varies by season and region, and between day and night. A synthesis of air temperature data from across the world reveals a greater rate of warming in winter than in summer in northern and high latitudes, but the inverse is true in some tropical regions.Also, the data show a decline in the daily temperature range over 51 percent of the globe and an increase over only 13 percent, because night-time temperatures in most locations have risen faster than daytime temperatures.From the data analyzed, a number of trends emerged in non-uniform climate warming for ecosystem carbon cycling. Spring warming will enhance ecosystem carbon uptake at high latitudes and diminish the magnitude of seasonal temperature change in these regions. Summer and autumn warming are more likely to reduce ecosystem carbon uptake in tropical ecosystems and amplify the magnitude of seasonal temperature change.The contrasting impacts of day- and night-time warming on plant carbon gain and loss are apparent in many regions. Day warming increases carbon uptake in most areas of tundra and boreal forests but decreases it in most grasslands and deserts. Night warming enhances carbon uptake in arid ecosystems, such as grassland desert but has negative impacts in other regions.Most of the existing temperature-manipulation experiments relied on continuous and uniform warming, so further research is needed to predict the effects of non-uniform climate warming on terrestrial carbon cycling. A paper on this study was accepted for early online publication on February 23, 2014, by Nature Geoscience.Story Source:The above story is based on materials provided by University of Oklahoma. …

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Spanish forest ecosystems: Carbon emission will be higher in second half of century

Spanish forest ecosystems will quite probably emit high quantities of carbon dioxide in the second half of the 21st century. This is the conclusion of a report that reviews the results obtained from the implementation of the forest simulation model GOTILWA+, a tool to simulate forest growth processes under several environmental conditions and to optimize Mediterranean forests management strategies in the context of climate change.The report was published on the latest issue of the ecology and environment journal Ecosistemas, edited by the Spanish Association of Terrestrial Ecology. Peer review was led by professors Santiago Sabat and Carlos Gracia, of the Department of Ecology at the University of Barcelona (UB) and the Centre for Ecological Research and Forestry Applications (CREAF), and the expert Daniel Nadal, of UB’s former Department.The study analyses data obtained from the simulation forest growth model GOTILWA+ (Growth Of Trees Is Limited by WAter), based on ecophysiological processes. The model enables to explore the effects of climate change on forestry ecosystems under changed environmental conditions and to simulate different management scenarios and compare them.Future perspectives for Spanish forestsIn climate change scenarios simulated by the model GOTILWA+ — within the Consolider-Ingenio project Montes and the research project Med-Forestream — , net primary productivity of Spanish forests (how much carbon dioxide plants take in during photosynthesis minus how much carbon dioxide they release during respiration) will decrease from the second half of this century. Consequently, woodlands that now drain carbon will become carbon producers because plant respiration (a process in which oxygen is taken in and carbon dioxide is given out) and the decomposition of death organic matter will exceed photosynthesis processes (carbon sequestration and oxygen release).GOTILWA+ also explores the responses of different forest types to water availability. Climate change involves an increase of aridity and evaporative rates. In this context, simulations show that an increase of evapotranspiration will occur in Spanish forests; it will have a negative impact on other ecosystems, for example, on rivers.The most sensitive areasThe most sensitive areas to climate change effects are Mediterranean forests of evergreen oak, Alepo pine and Scots pine, located in the south-west of the Iberian Peninsula. Forest located in the north-west will be also affected, as simulations show a severe precipitation decrease in this area. Moreover, simulations show an increase of these forests’ sensitivity to aridity. For instance, beech forests are particularly sensitive to a slight increase in average temperature as well as those forests located at low height, so altitudinal migrations will probably occur.Forest management: key to mitigate climate change impactIn the report, Gracia, Sabat and Nadal highlight that management strategies adapted to environmental changes are crucial to the conservation of Iberian forests and the resources they provide to society. …

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Roots to shoots: Hormone transport in plants deciphered

Plant growth is orchestrated by a spectrum of signals from hormones within a plant. A major group of plant hormones called cytokinins originate in the roots of plants, and their journey to growth areas on the stem and in leaves stimulates plant development. Though these phytohormones have been identified in the past, the molecular mechanism responsible for their transportation within plants was previously poorly understood.Now, a new study from a research team led by biochemist Chang-Jun Liu at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory identifies the protein essential for relocating cytokinins from roots to shoots.The research is reported in the February 11 issue of Nature Communications.Cytokinins stimulate shoot growth and promote branching, expansion and plant height. Regulating these hormones also improves the longevity of flowering plants, tolerance to drought or other environmental stresses, and the efficiency of nitrogen-based fertilizers.Manipulating cytokinin distribution by tailoring the action of the transporter protein could be one way to increase biomass yield and stress tolerance of plants grown for biofuels or agriculture. “This study may open new avenues for modifying various important crops, agriculturally, biotechnologically, and horticulturally, to increase yields and reduce fertilizer requirements, for instance, while improving the exploitation of sustainable bioenergy resources,” Liu said.Using Arabidopsis, a small flowering plant related to mustard and cabbage that serves as a common experimental model, the researchers studied a large family of transport proteins called ATP-binding cassette (ABC) transporters, which act as a kind of inter- or intra-cellular pump moving substances in or out of a plant’s cells or their organelles. While performing gene expression analysis on a set of these ABC transporters, the research team found that one gene — AtABCG14 – is highly expressed in the vascular tissues of roots.To determine its function, they examined mutant plants harboring a disrupted AtABCG14 gene. They found that knocking out this transporter gene resulted in plants with weaker growth, slenderer stems, and shorter primary roots than their wild-type counterparts. These structural changes in the plants are symptoms of cytokinin deficiencies. Essentially, the long-distance transportation of the growth hormones is impaired, which causes alterations in the development of roots and shoots. …

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Is an earthquake behind the Shroud of Turin image? Radiation from earthquake could have led to ‘wrong’ 1988 dating

Neutron radiation caused by 33 A.D. earthquake could have led to “wrong” 1988 radiocarbon dating of Shroud, suggest researchersAn earthquake in Old Jerusalem might be behind the famous image of the Shroud of Turin, says a group of researchers led by Alberto Carpinteri of the Politecnico di Torino in Italy in an article published in Springer’s journal Meccanica. They believe that neutron radiation caused by an earthquake could have induced the image of a crucified man — which many people believe to be that of Jesus — onto the length of linen cloth, and caused carbon-14 dating done on it in 1988 to be wrong.The Shroud has attracted widespread interest ever since Secondo Pia took the first photograph of it in 1898: about whether it is Jesus’ purported burial cloth, how old it might be, and how the image was created. According to radiocarbon dating done in 1988, the cloth was only 728 years old at the time. Other researchers have since suggested that the shroud is much older and that the dating process was incorrect because of neutron radiation — a process which is the result of nuclear fusion or nuclear fission during which free neutrons are released from atoms — and its interaction with the nuclei of other atoms to form new carbon isotopes.However, no plausible physical reason has yet been proposed to explain the origin of this neutron radiation. Now Carpinteri’s team, through mechanical and chemical experimentation, hypothesizes that high-frequency pressure waves generated in Earth’s crust during earthquakes are the source of such neutron emissions. This is based on their research into piezonuclear fission reactions, which are triggered when very brittle rock specimens are crushed under a press machine. In the process, neutrons are produced without gamma emissions. Analogously, the researchers theorize further that neutron flux increments, in correspondence to seismic activity, should be a result of the same reactions.The researchers therefore believe that neutron emission from a historical earthquake in 33 A.D. in Old Jerusalem, which measured 8.2 on the Richter Scale, could have been strong enough to cause neutron imaging through its interaction with nitrogen nuclei. …

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New maps highlight habitat corridors in the tropics

A team of Woods Hole Research Center (WHRC) scientists created maps of habitat corridors connecting protected areas in the tropics to incorporate biodiversity co-benefits into climate change mitigation strategies. Drs. Patrick Jantz, Scott Goetz, and Nadine Laporte describe their findings in an article entitled, “Carbon stock corridors to mitigate climate change and promote biodiversity in the tropics,” available online in the journal Nature Climate Change on January 26.Climate change and deforestation are changing tropical ecosystems, isolating organisms in protected areas that will change along with climate, threatening their survival. Nearly every animal and plant species requires travelling some distance for nutrition, reproduction and genetic diversity, but few conservation or climate mitigation strategies take the connections between conserved lands into account. These habitat corridors are essential for longer-term biodiversity conservation, while also providing opportunities for climate change mitigation in the form of carbon sequestration and avoiding emissions from deforestation.According to lead author Dr. Jantz, “Maintaining connectivity of forest ecosystems provides ecological and societal benefits ensuring long-term species survival and providing room for ecosystems to reorganize in response to climate change and protecting ecosystem services that people depend on.” Co-author Dr. Goetz sees corridors as “avenues for migration of flora and fauna” needed for their survival “under the climate change we’re already committed to.”The team used a high-resolution data set of vegetation carbon stock (VCS) to map 16,257 corridors through areas of the highest biomass between 5,600 protected areas in the tropics. For Dr. Jantz, “the VCS corridor approach informs global frameworks for land management based climate change mitigation by showing which forests contain significant carbon stocks and are important for tropical biodiversity.”Part of the study focused on the Legal Amazon, where the team used economic and biological information combining species richness and endemism with economic opportunity costs and deforestation threats to prioritize optimal corridors. For Dr. …

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New catalyst to convert greenhouse gases into chemicals

A team of researchers at the University of Delaware has developed a highly selective catalyst capable of electrochemically converting carbon dioxide — a greenhouse gas — to carbon monoxide with 92 percent efficiency. The carbon monoxide then can be used to develop useful chemicals.The researchers recently reported their findings in Nature Communications.”Converting carbon dioxide to useful chemicals in a selective and efficient way remains a major challenge in renewable and sustainable energy research,” according to Feng Jiao, assistant professor of chemical and biomolecular engineering and the project’s lead researcher.Co-authors on the paper include Qi Lu, a postdoctoral fellow, and Jonathan Rosen, a graduate student, working with Jiao.The researchers found that when they used a nano-porous silver electrocatalyst, it was 3,000 times more active than polycrystalline silver, a catalyst commonly used in converting carbon dioxide to useful chemicals.Silver is considered a promising material for a carbon dioxide reduction catalyst because of it offers high selectivity — approximately 81 percent — and because it costs much less than other precious metal catalysts. Additionally, because it is inorganic, silver remains more stable under harsh catalytic environments.The exceptionally high activity, Jiao said, is likely due to the UD-developed electrocatalyst’s extremely large and highly curved internal surface, which is approximately 150 times larger and 20 times intrinsically more active than polycrystalline silver.Jiao explained that the active sites on the curved internal surface required a much smaller than expected voltage to overcome the activation energy barrier needed drive the reaction.The resulting carbon monoxide, he continued, can be used as an industry feedstock for producing synthetic fuels, while reducing industrial carbon dioxide emissions by as much as 40 percent.To validate whether their findings were unique, the researchers compared the UD-developed nano-porous silver catalyst with other potential carbon dioxide electrocatalysts including polycrystalline silver and other silver nanostructures such as nanoparticles and nanowires.Testing under identical conditions confirmed the non-porous silver catalyst’s significant advantages over other silver catalysts in water environments.Reducing greenhouse carbon dioxide emissions from fossil fuel use is considered critical for human society. Over the last 20 years, electrocatalytic carbon dioxide reduction has attracted attention because of the ability to use electricity from renewable energy sources such as wind, solar and wave.Ideally, Jiao said, one would like to convert carbon dioxide produced in power plants, refineries and petrochemical plants to fuels or other chemicals through renewable energy use.A 2007 Intergovernmental Panel on Climate Change report stated that 19 percent of greenhouse gas emissions resulted from industry in 2004, according to the Environmental Protection Agency’s website.”Selective conversion of carbon dioxide to carbon monoxide is a promising route for clean energy but it is a technically difficult process to accomplish,” said Jiao. “We’re hopeful that the catalyst we’ve developed can pave the way toward future advances in this area.”The research team’s work is supported through funding from the American Chemical Society Petroleum Research Fund and University of Delaware Research Foundation. Jiao has patented the novel application technique in collaboration with UD’s Office of Economic Innovation and Partnerships.Story Source:The above story is based on materials provided by University of Delaware. The original article was written by Karen B. Roberts. Note: Materials may be edited for content and length.

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Unprecedented rate and scale of ocean acidification found in the Arctic

Sep. 12, 2013 — Acidification of the Arctic Ocean is occurring faster than projected, according to new findings published in the journal PLoS ONE. The increase in rate is being blamed on rapidly melting sea ice, a process that may have important consequences for health of the Arctic ecosystem.Ocean acidification is the process by which pH levels of seawater decrease due to greater amounts of carbon dioxide being absorbed by the oceans from the atmosphere. Currently oceans absorb about one-fourth of the greenhouse gas. Lower pH levels make water more acidic and lab studies have shown that more acidic water decrease calcification rates in many calcifying organisms, reducing their ability to build shells or skeletons. These changes, in species ranging from corals to shrimp, have the potential to impact species up and down the food web.The team of federal and university researchers found that the decline of sea ice in the Arctic summer has important consequences for the surface layer of the Arctic Ocean. As sea ice cover recedes to record lows, as it did late in the summer of 2012, the seawater beneath is exposed to carbon dioxide, which is the main driver of ocean acidification.In addition, the freshwater melted from sea ice dilutes the seawater, lowering pH levels and reducing the concentrations of calcium and carbonate, which are the constituents, or building blocks, of the mineral aragonite. Aragonite and other carbonate minerals make up the hard part of many marine micro-organisms’ skeletons and shells. The lowering of calcium and carbonate concentrations may impact the growth of organisms that many species rely on for food.The new research shows that acidification in surface waters of the Arctic Ocean is rapidly expanding into areas that were previously isolated from contact with the atmosphere due to the former widespread ice cover.”A remarkable 20 percent of the Canadian Basin has become more corrosive to carbonate minerals in an unprecedented short period of time. Nowhere on Earth have we documented such large scale, rapid ocean acidification” according to lead researcher and ocean acidification project chief, U.S. …

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Century old chemistry problem solved: Foundational reaction on stubborn chemicals may improve drug synthesis

Sep. 11, 2013 — Chemists at The Scripps Research Institute (TSRI) have found a way to apply a “foundational reaction” of organic chemistry to a stubborn class of chemicals, in a transformation that has been thought impossible for a century.The classic SN2 reaction has enabled chemists to build and modify many pharmaceuticals as well as other useful organic molecules. While the reaction had been thought to exclude certain compounds, a paper in the September 12, 2013 issue of the journal Nature describes a new SN2-like reaction that overcomes this limitation.”We’ve widened the range of molecules that are responsive to this foundational technique; for example, we can now chemically synthesize a family of promising antimalarial and anticancer compounds that were previously off limits,” said TSRI Assistant Professor Ryan A. Shenvi, who was the senior author of the paper.Flipping the UmbrellaThe SN2 reaction can be used to detach part of a molecule called a functional group from a central carbon atom, while simultaneously, another functional group adds to the opposite side of the carbon atom. This structural flip can significantly change a compound’s chemical properties.”It’s like turning an umbrella inside out,” Shenvi said. “The SN2 predictably inverts what we call the stereochemistry of the carbon atom.”Traditionally, stereoinversion reactions, which were first described by Paul Walden in 1896, have not been applicable to compounds known as tertiary alcohols or their derivatives — a general problem identified by Christopher Ingold in the early 1900s. In these compounds, the carbon atom of interest is bonded to three other carbon atoms, which effectively shield it from the reaction.To get around this longstanding limitation, Shenvi and his research associate Sergey V. Pronin developed a method that employs a special acid catalyst plus an unusual nitrogen-containing molecule, a derivative of cyanide. The acid helps detach a fluorous functional group from one side of the central carbon atom, and then the nitrogen forms a new bond on the other side, thus completing the stereoinversion.”The basic idea is that you can take a tertiary alcohol with one stereochemical configuration and install nitrogen functionality, leaving it with the opposite stereochemical configuration,” said Pronin.Fewer StepsTo demonstrate the new technique, Pronin and graduate student Chris Reiher used it to build or modify a number of compounds in a relatively short sequence of reaction steps, starting with cheaply available tertiary alcohols. “In one example, we took a derivative of vitamin E, tocopherol, and in a few steps turned it into something we call an aza-tocopherol, in which the oxygen atom is replaced with nitrogen — a compound that otherwise would have been very difficult to access,” Pronin said.The chemists also showed how the new reaction can simplify the preparation of a set of compounds known as marine isocyanoterpenes, which are produced naturally by sea sponges and other oceanic animals. …

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Comet discovered hiding in plain sight: Near-Earth asteroid is really a comet

Sep. 10, 2013 — For 30 years, a large near-Earth asteroid wandered its lone, intrepid path, passing before the scrutinizing eyes of scientists while keeping something to itself: 3552 Don Quixote, whose journey stretches to the orbit of Jupiter, now appears to be a comet.The discovery resulted from an ongoing project led by researchers at Northern Arizona University using the Spitzer Space Telescope. Through a lot of focused attention and a little bit of luck, they found evidence of cometary activity that had evaded detection for three decades.”Its orbit resembled that of a comet, so people assumed it was a comet that had gotten rid of all its ice deposits,” said Michael Mommert, a post-doctoral researcher at NAU who was a Ph.D. student of professor Alan Harris at the German Aerospace Center (DLR) in Berlin at the time the work was carried out.What Mommert and an international team of researchers discovered, though, was that Don Quixote was not actually a dead comet — one that had shed the carbon dioxide and water that give comets their spectacular tails.Instead, the third-biggest near-Earth asteroid out there, skirting Earth with an erratic, extended orbit, is “sopping wet,” said NAU associate professor David Trilling. The implications have less to do with potential impact, which is extremely unlikely in this case, and more with “the origins of water on Earth,” Trilling said. Comets may be the source of at least some of it, and the amount on Don Quixote represents about 100 billion tons of water — roughly the same amount found in Lake Tahoe.Mommert said it’s surprising that Don Quixote hasn’t been depleted of all of its water, especially since researchers assumed that it had done so thousands of years ago. But finding evidence of CO2, and presumably water, wasn’t easy.During an observation of the object using Spitzer in August 2009, Mommert and Trilling found that it was far brighter than they expected. “The images were not as clean as we would like, so we set them aside,” Trilling said.Much later, though, Mommert prompted a closer look, and partners at the Harvard-Smithsonian Center for Astrophysics found something unusual when comparing infrared images of the object: something, that is, where an asteroid should have shown nothing. The “extended emission,” Mommert said, indicated that Don Quixote had a coma — a comet’s visible atmosphere — and a faint tail.Mommert said this discovery implies that carbon dioxide and water ice also might be present on other near-Earth objects.This study confirmed Don Quixote’s size and the low, comet-like reflectivity of its surface. Mommert is presenting the research team’s findings this week at the European Planetary Space Conference in London.

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Climate change will upset vital ocean chemical cycles

Sep. 8, 2013 — New research from the University of East Anglia shows that rising ocean temperatures will upset natural cycles of carbon dioxide, nitrogen and phosphorus.Plankton plays an important role in the ocean’s carbon cycle by removing half of all CO2 from the atmosphere during photosynthesis and storing it deep under the sea — isolated from the atmosphere for centuries.Findings published today in the journal Nature Climate Change reveal that water temperature has a direct impact on maintaining the delicate plankton ecosystem of our oceans.The new research means that ocean warming will impact plankton, and in turn drive a vicious cycle of climate change.Researchers from UEA’s School of Environmental Sciences and the School of Computing Sciences investigated phytoplankton — microscopic plant-like organisms that rely on photosynthesis to reproduce and grow.Lead researcher Dr Thomas Mock, said: “Phytoplankton, including micro-algae, are responsible for half of the carbon dioxide that is naturally removed from the atmosphere. As well as being vital to climate control, it also creates enough oxygen for every other breath we take, and forms the base of the food chain for fisheries so it is incredibly important for food security.”Previous studies have shown that phytoplankton communities respond to global warming by changes in diversity and productivity. But with our study we show that warmer temperatures directly impact the chemical cycles in plankton, which has not been shown before.”Collaborators from the University of Exeter, who are co-authors of this study, developed computer generated models to create a global ecosystem model that took into account world ocean temperatures, 1.5 million plankton DNA sequences taken from samples, and biochemical data.”We found that temperature plays a critical role in driving the cycling of chemicals in marine micro-algae. It affects these reactions as much as nutrients and light, which was not known before,” said Dr Mock.”Under warmer temperatures, marine micro-algae do not seem to produce as many ribosomes as under lower temperatures. Ribosomes join up the building blocks of proteins in cells. They are rich in phosphorus and if they are being reduced, this will produce higher ratios of nitrogen compared to phosphorus, increasing the demand for nitrogen in the oceans.”This will eventually lead to a greater prevalence of blue-green algae called cyanobacteria which fix atmospheric nitrogen,” he added.

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Global warming has increased risk of record heat

Sep. 5, 2013 — Researchers calculate that intense heat like that in the summer of 2012 is up to four times more likely to occur now than in pre-industrial America, when there was much less carbon dioxide in the atmosphere.Drought shriveled crops in the Midwest, massive wildfires raged in the West and East Coast cities sweltered. The summer of 2012 was a season of epic proportions, especially July, the hottest month in the history of U.S. weather record keeping.And it’s likely that we’ll continue to see such calamitous weather.In the north-central and northeastern United States, extreme weather is more than four times as likely to occur than it was in the pre-industrial era, according to a new study by Noah Diffenbaugh, a Stanford associate professor of environmental Earth system science, and Martin Scherer, a research assistant in the department.Diffenbaugh and Scherer found strong evidence that the high levels of greenhouse gases now in the atmosphere have increased the likelihood of severe heat such as occurred in the United States in 2012.The researchers focused primarily on understanding the physical processes that created the hazardous weather. They looked at how rare those conditions were over the history of available weather records, going back over the last century.Then, using climate models, they quantified how the risk of such damaging weather has changed in the current climate of high greenhouse gas concentrations, as opposed to an era of significantly lower concentrations and no global warming. Their findings don’t pinpoint global warming as the cause of particular extreme weather events, but they do reveal the increasing risk of such events as the world warms.”Going forward, if we want to understand and manage climate risks, it’s more practically relevant to understand the likelihood of the hazard than to ask whether any particular disaster was caused by global warming,” Diffenbaugh said.In 2012 alone, the United States suffered 11 extreme weather events that each caused at least $1 billion in damage. “It’s clear that our greenhouse gas emissions have increased the likelihood of some kinds of extremes, and it’s clear that we’re not optimally adapted to that new climate,” Diffenbaugh said.While Diffenbaugh cautions against trying to determine whether global warming caused any individual extreme event, the observed global warming clearly appears to have affected the likelihood of record heat, according to Diffenbaugh and Scherer.The study, looking at the likelihood of July 2012 U.S. temperatures recurring, is part of a larger report edited by scientists at the National Oceanic and Atmospheric Administration (NOAA) and published Sept. 5 in the Bulletin of the American Meteorological Society. The report includes studies of a dozen 2012 extreme weather events by research teams around the world, about half of which found some evidence that human-caused climate change contributed to an extreme weather event.Close study of extreme weather events can help quantify the likelihood that society will face conditions similar to those that occurred in the summer of 2012, thereby informing efforts to reduce vulnerability and increase resilience. …

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Sharing the risks/costs of biomass crops

Sep. 4, 2013 — Farmers who grow corn and soybeans can take advantage of government price support programs and crop insurance, but similar programs are not available for those who grow biomass crops such as Miscanthus. A University of Illinois study recommends a framework for contracts between growers and biorefineries to help spell out expectations for sustainability practices and designate who will assume the risks and costs associated with these new perennial energy crops.”The current biomass market operates more along the lines of a take-it-or-leave-it contract, but in order to encourage enhanced participation and promote a more sustainable, stable biomass supply, a new kind of contract needs to be created,” said Jody Endres, a U of I professor of energy and environmental law.Endres said that a good contract gives everyone more certainty.”Incomplete contracts are the hazard,” she said. “We need to develop contracts that nail down all of the details and are transparent about who’s taking on the risk and who’s paying for it. If we get these considerations into the contracts, those who finance this new biomass crop industry will have more certainty to invest.”The study identifies considerations that should be included in the framework for a biomass contract, including a control for moral hazard, risk incentive tradeoff, existing agricultural practices, and risk and management tools to make the industry more sustainable financially and environmentally.Endres said that if biorefineries receive money in the form of carbon credits for reducing pollution, incentives for farmers should be included in contracts because they are the ones who are bearing the risks associated with sustainability practices.”Suppose a sustainability contract lists that the default should be integrated pest management rather than application of traditional pesticides,” Endres said. “The farmer takes on some risk to provide a sustainable product, but the biorefinery gets carbon credit for those sustainable practices. This should be worked into the contract — that if the farmer assumes the risk of IPM as opposed to traditional pesticide options, there has to be some sort of up-front payment or incentive in the contract to account for this risk. Due to the power relationships in this industry, the onus is on the biorefinery to be the leader in developing contracts in this new landscape.”The perennial nature of biomass crops also makes developing contracts challenging.”We’re in a unique environment, and traditional agricultural contracting structures just don’t apply,” Endres said. “Crop insurance is not currently available for farmers who grow biomass crops so they take on additional risk. Likewise, landowners see high prices for traditional commodity crops and do not want to be locked into a multi-year contract with a lessee to grow a perennial biomass crop. …

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Scientists analyze the effects of ocean acidification on marine species

Aug. 25, 2013 — Ocean acidification could change the ecosystems of our seas even by the end of this century. Biologists at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), have therefore assessed the extent of this ominous change for the first time. In a new study they compiled and analysed all available data on the reaction of marine animals to ocean acidification. The scientists found that whilst the majority of animal species investigated are affected by ocean acidification, the respective impacts are very specific.The AWI-researchers present their results as an Advance Online Publication on Sunday 25 August 2013 in Nature Climate Change.The oceans absorb more than a quarter of anthropogenic carbon dioxide emitted to the atmosphere. They form a natural store without which Earth would now be a good deal warmer. But their storage capacities are limited and the absorption of carbon dioxide is not without consequence. Carbon dioxide dissolves in water, forms carbonic acid and causes the pH value of the oceans to drop — which affects many sea dwellers. In recent years much research has therefore been conducted on how individual species react to the carbon dioxide enrichment and the acidifying water. So far the overall extent of these changes on marine animals has been largely unknown.In order to gain an initial overview, Dr. …

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Pop! Bursting the bubble on carbonation

Aug. 22, 2013 — New research from the Monell Center reveals that bubbles are not necessary to experience the unique ‘bite’ of carbonated beverages. Bubbles do, however, enhance carbonation’s bite through the light feel of the bubbles picked up by our sense of touch.The refreshing bite of carbonation is an integral part of beverages consumed around the globe. Carbonated beverages are produced when carbon dioxide is dissolved in a liquid, typically under high pressure. This can happen naturally in certain spring waters or in fermented beverages like beer. Carbon dioxide also can be added to beverages through production processes.In either case, when pressure is reduced by opening a bottle or can of a carbonated beverage, some of the carbon dioxide is released from the solution in the form of bubbles. After a sip, enzymes in the mouth convert the remaining free carbon dioxide into carbonic acid. The acid then activates sensory nerve endings, which signal the mild irritation that we refer to as ‘bite.’In the study, published in the public access journal PLOS ONE, the Monell researchers examined the role that bubbles play in carbonation bite. In the first experiment, they took advantage of the fact that bubbles cannot form when atmospheric pressure is raised above a certain level.Twelve healthy adults were comfortably seated in a hyperbaric chamber and asked to rate the bite intensity of several concentrations of carbonated water. The ratings were collected once while under normal atmospheric pressure (with bubbles) and a second time at higher pressure (no bubbles), equivalent to diving to a depth of 33 feet in sea water.There was no difference in the bite reported in the two conditions, even though bubbles are physically unable to form at the higher pressure.”Because the subjects experienced the same bite when bubbles weren’t present, the findings clearly told us that carbonation bite is an acidic chemical sensation rather than a purely physical, tactile one,” said study author Bruce Byant, PhD, a sensory biologist at Monell.Although bubbles aren’t necessary for bite, they still could be contributing to the overall sensation of carbonation. …

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Extreme weather events fuel climate change

Aug. 14, 2013 — In 2003, Central and Southern Europe sweltered in a heatwave that set alarm bells ringing for researchers. It was one of the first large-scale extreme weather events which scientists were able to use to document in detail how heat and drought affected the carbon cycle (the exchange of carbon dioxide between the terrestrial ecosystems and the atmosphere). Measurements indicated that the extreme weather events had a much greater impact on the carbon balance than had previously been assumed. It is possible that droughts, heat waves and storms weaken the buffer effect exerted by terrestrial ecosystems on the climate system. In the past 50 years, plants and the soil have absorbed up to 30% of the carbon dioxide that humans have set free, primarily from fossil fuels.The indications that the part played by extreme weather events in the carbon balance had been underestimated prompted scientists from eight countries to launch the CARBO-Extreme Project. For the first time, the consequences of various extreme climate events on forests, bogs, grass landscapes and arable areas throughout the world underwent systematic scrutiny.Satellites and recording stations document extreme eventsThe researchers working with Markus Reichstein took different approaches to their study from the ecosystem perspective. Satellite images from 1982 to 2011 revealed how much light plants in an area absorb so that they can perform photosynthesis. From this, they were able to determine how much biomass the ecosystem in question accumulates during or after an extreme weather event. The researchers also used data from a global network of 500 recording stations, some in operation for more than 15 years, which record carbon dioxide concentrations and air currents in the atmosphere a few meters above ground or in forest canopies. …

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Baby corals pass the acid test

Aug. 13, 2013 — Corals can survive the early stages of their development even under the tough conditions that rising carbon emissions will impose on them says a new study from the ARC Centre of Excellence for Coral Reef Studies.Globally, ocean acidification due to the burning of fossil fuels remains a major concern and scientists say it could have severe consequences for the health of adult corals, however, the evidence for negative effects on the early life stages of corals is less clear cut.Dr Andrew Baird, Principal Research Fellow at the ARC Centre of Excellence for Coral Reef Studies and James Cook University, was part of the research team and explains their findings.”The prevailing view is that ocean acidification will act like a toxin to corals, but we were unconvinced by results from previous work on young corals and ocean acidification so we tested critical early stages of development in several coral species at several different acid (or ‘pH’) concentrations of seawater.”Our results showed no clear response to increasing ocean acidification in any of the stages, or for any of the coral species,” says Dr Baird. “In fact, in only one of nine experiments did we get the response expected if CO2 was acting like a toxin. More often than not we found no effect.”By bubbling CO2 through seawater the research team was able to simulate future levels of ocean acidification expected to result from rising human carbon emissions. They tested the success of embryo development, the survival of coral larvae and finally their success in settling on coral reefs.Although their results suggest that ocean acidification may not affect the early stages of coral development, the team warn that this does not mean acidification is not a threat to corals.”Undoubtedly, as the oceans become more acidic adult corals are going to struggle to build their skeletons, which might hinder their ability to grow, reproduce and compete for space on reefs. We also have to remember that the oceans are getting warmer, so corals will be dealing with higher temperatures, as well as higher acidity.”Fortunately, before corals settle on to reefs they don’t need to grow a skeleton, which might explain why they are apparently unaffected in by higher levels of ocean acidification,” says Dr Chia-Miin Chua, the lead author of the study.”This message is reinforced when we look at the early life stages of creatures that do need a larval skeleton, such as sea urchins and oysters. In these cases we see early life stage development slowing down as acidity increases.”However the study does not discount the possibility that coral larvae may suffer other ill-effects from increasing ocean acidification, for example, their swimming speeds may slow down, but because coral larvae typically settle on the reef two or three weeks after birth it is unlikely that these effects will have a major impact on the survival or settlement of coral larvae.Dr Baird says that while the long-term outlook for corals may be gloomy, this research highlights the fact that not all life stages of corals will be equally affected.

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Weeds threaten carbon offset programs

Aug. 12, 2013 — Researchers have identified gamba grass and other invasive weeds as a potential threat to landholder involvement in environmental offset programs such as the Carbon Farming Initiative.Strategic savanna burning is one way to reduce Australia’s carbon emissions and create new markets in northern Australia, but the increased fuel load and emissions from weed infestations could make it unfeasible.Dr Vanessa Adams says that late dry season wildfires in Australia’s tropical north generate about 3% of the country’s annual greenhouse gas emissions, so strategic burning could be an important abatement activity.”But when native savannas are invaded by weeds such as gamba grass, fuel loads are dramatically increased and fires can burn up to five times hotter than a native wildfire,” Dr Adams said.”We examined the spatial and financial extent of the threat of gamba grass and found that 75% of the area across northern Australia suitable for savanna burning is also highly suitable for gamba grass.”There’s a large disparity between the profits generated from savanna burning — $1.92 per hectare — and the costs of managing gamba grass — $40 per hectare — meaning that much more savanna needs to be enrolled for carbon farming to cover the costs of weed eradication.”The good news is that in the Northern Territory, only about 20% of properties that could run profitable savanna burning programs had gamba grass, and of these, about 16% had small infestations.”A one-off investment of $200,000 would eradicate these infestations, and for the majority of properties that are gamba free, an effective control program would safeguard them into the future.”It’s really important we look at how these types of barriers might prevent landholders from getting involved in environmental offset programs and that we strategically manage weeds so that they don’t become an intractable problem in the future.”

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