A study led by the University of Leeds has shown that global warming of only 2C will be detrimental to crops in temperate and tropical regions, with reduced yields from the 2030s onwards.Professor Andy Challinor, from the School of Earth and Environment at the University of Leeds and lead author of the study, said: “Our research shows that crop yields will be negatively affected by climate change much earlier than expected.””Furthermore, the impact of climate change on crops will vary both from year-to-year and from place-to-place — with the variability becoming greater as the weather becomes increasingly erratic.”The study, published today by the journal Nature Climate Change, feeds directly into the Working Group II report of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report, which is due to be published at the end of March 2014.In the study, the researchers created a new data set by combining and comparing results from 1,700 published assessments of the response that climate change will have on the yields of rice, maize and wheat.Due to increased interest in climate change research, the new study was able to create the largest dataset to date on crop responses, with more than double the number of studies that were available for researchers to analyze for the IPCC Fourth Assessment Report in 2007.In the Fourth Assessment Report, scientists had reported that regions of the world with temperate climates, such as Europe and most of North America, could withstand a couple of degrees of warming without a noticeable effect on harvests, or possibly even benefit from a bumper crop.”As more data have become available, we’ve seen a shift in consensus, telling us that the impacts of climate change in temperate regions will happen sooner rather than later,” said Professor Challinor.The researchers state that we will see, on average, an increasingly negative impact of climate change on crop yields from the 2030s onwards. The impact will be greatest in the second half of the century, when decreases of over 25% will become increasingly common.These statistics already account for minor adaptation techniques employed by farmers to mitigate the effects of climate change, such as small adjustments in the crop variety and planting date. Later in the century, greater agricultural transformations and innovations will be needed in order to safeguard crop yields for future generations.”Climate change means a less predictable harvest, with different countries winning and losing in different years. The overall picture remains negative, and we are now starting to see how research can support adaptation by avoiding the worse impacts,” concludes Professor Challinor.Story Source:The above story is based on materials provided by University of Leeds. Note: Materials may be edited for content and length.Read more
Famous People Who Battled Mesothelioma Mesothelioma is a cancer most often associated with military service and blue-collar professions, but theRead more
Unique and irreplaceable Arctic wildlife and landscapes are crucially at risk due to global warming caused by human activities according to the Arctic Biodiversity Assessment (ABA), a new report prepared by 253 scientists from 15 countries under the auspices of the Conservation of Arctic Flora and Fauna (CAFF), the biodiversity working group of the Arctic Council.”An entire bio-climatic zone, the high Arctic, may disappear. Polar bears and the other highly adapted organisms cannot move further north, so they may go extinct. We risk losing several species forever,” says Hans Meltofte of Aarhus University, chief scientist of the report.From the iconic polar bear and elusive narwhal to the tiny Arctic flowers and lichens that paint the tundra in the summer months, the Arctic is home to a diversity of highly adapted animal, plant, fungal and microbial species. All told, there are more than 21,000 species.Maintaining biodiversity in the Arctic is important for many reasons. For Arctic peoples, biodiversity is a vital part of their material and spiritual existence. Arctic fisheries and tourism have global importance and represent immense economic value. Millions of Arctic birds and mammals that migrate and connect the Arctic to virtually all parts of the globe are also at risk from climate change in the Arctic as well as from development and hunting in temperate and tropical areas. Marine and terrestrial ecosystems such as vast areas of lowland tundra, wetlands, mountains, extensive shallow ocean shelves, millennia-old ice shelves and huge seabird cliffs are characteristic to the Arctic. These are now at stake, according to the report.”Climate change is by far the worst threat to Arctic biodiversity. Temperatures are expected to increase more in the Arctic compared to the global average, resulting in severe disruptions to Arctic biodiversity some of which are already visible,” warns Meltofte.A planetary increase of 2 C, the worldwide agreed upon acceptable limit of warming, is projected to result in vastly more heating in the Arctic with anticipated temperature increases of 2.8-7.8 C this century. …Read more
Scientists have studied a visual illusion first discovered by Galileo Galilei, and found that it occurs because of the surprising way our eyes see lightness and darkness in the world. Their results advance our understanding of how our brains are wired for seeing white versus black objects.The work was done by Jens Kremkow and collaborators in the laboratories of Jose Manuel Alonso and Qasim Zaidi at the State University of New York College of Optometry. It will be published on February 10 of 2014 in the Proceedings of the National Academy of Sciences.Galileo was puzzled by the fact that the appearance of the planets depended on whether one looked with the naked eye or with a telescope. Viewed directly, planets seemed “expanded” and had “a radiant crown,” which made Venus looked eight to ten times larger than Jupiter even though Jupiter was four times larger. Though Galileo realized this size illusion was not created by the object — but by his eyes — he did not understand why or how.He mused, “Either because their light is refracted in the moisture that covers the pupil, or because it is reflected from the edges of the eyelids and these reflected rays are diffused over the pupil, or for some other reason.” Generations of scientists following Galileo continued to assume the illusion was caused by blur or similar optical effects. However, though blur can distort size, it does not explain why Venus looks larger than Jupiter with the naked eye. Hermann von Helmholtz — the venerable 19th Century German physician-physicist — was the first to realize that something else was needed to explain the illusion, as he described in his Treatise on Physiological Optics.Only now, with Kremkow and colleagues’ new study, has science finally zoomed in and illuminated the scope of the problem. It’s a feature of how we see everything, no less. By examining the responses of neurons in the visual system of the brain — to both light stimuli and dark stimuli — the neuroscientists discovered that, whereas dark stimuli result in a faithful neural response that accurately represents their size, light stimuli on the contrary result in non-linear and exaggerated responses that make the stimulus look larger. So white spots on a black background look bigger than same-sized black spots on white background, and Galileo’s glowing stellar objects are not really as big as they might appear to the unaided eye.This effect is responsible for how we see everything from textures and faces — based on their dark parts in bright daylight — to why it is easier to read this very page with black-on-white lettering, rather than white-on-black (a well known, and until now, unexplained phenomenon). …Read more
Sep. 11, 2013 — The technology that peeks underneath clothing at airport security screening check points has great potential for looking underneath human skin to diagnose cancer at its earliest and most treatable stages, scientists say.Anis Rahman, Ph.D., who spoke on the topic, explained that malignant melanoma, the most serious form of skin cancer, starts in pigment-producing cells located in the deepest part of the epidermis. That’s the outer layer of the skin. Biochemical changes that are hallmarks of cancer occur in the melanocytes long before mole-like melanomas appear on the skin.”Terahertz radiation is ideal for looking beneath the skin and detecting early signs of melanoma,” Rahman said. “T-rays are different from X-rays, which are ‘ionizing’ radiation that can cause damage. T-rays are a form of ‘non-ionizing’ radiation, like ordinary visible light, but they can be focused harmlessly below into the body and capture biochemical signatures of events like the start of cancer.”T-rays occupy a niche in the spectrum of electromagnetic radiation, which includes X-rays and visible light, between microwaves like those used in kitchen ovens and the infrared rays used in TV remote controls. One of the advantages of T-rays is that they penetrate only a few millimeters through cloth, skin and other non-metallic material. Ten sheets of printer paper would be about 1 millimeter thick. This key characteristic has led to their use in quality control in the pharmaceutical industry to check the surface integrity of pills and capsules, in homeland security to remotely frisk underneath clothes, and as a non-destructive way of probing beneath the top layers of famous paintings and other culturally significant artwork.Rahman, president and chief technology officer of Applied Research & Photonics in Harrisburg, Pa., said that medical imaging is one of their newest and most promising potential uses. He described research focusing T-rays through donated samples of human skin that suggest the technology could be valuable in diagnosing melanoma.In addition to developing T-rays for cancer diagnostics, Rahman’s team has successfully harnessed them to measure the real-time absorption rates and penetration in the outer layer of skin of topically applied drugs and shampoo — measurements that until now had not been possible.Other wide-ranging applications include the detection of early stages of tooth decay, trace pesticides on produce, flaws in pharmaceutical tablet coatings, and concealed weapons under clothing, as well as testing the effectiveness of skin cosmetics. …Read more
Sep. 11, 2013 — Global warming could impact the El Niño Southern Oscillation (ENSO), altering the cycles of El Niño and La Niña events that bring extreme drought and flooding to Australia and many other Pacific-rim countries.New research published in Nature Geoscience using coral samples from Kiribati has revealed how the ENSO cycle has changed over the past 4300 years. This research suggests that external changes have an impact on the strength and timing of El Niño events.”Our research has showed that while the development of La Niña and El Niño events is chaotic and hard to predict, the strength of these events can change over long time spans due to changes in the global climate,” said one of the paper’s authors Dr Steven Phipps.”For instance, we found that the ENSO cycle was much weaker 4300 years ago than it is today. This weaker cycle persisted for almost two centuries.”The researchers determined that natural influences on Earth’s climate, such as those caused by variations in its orbit around the sun, could affect the strength of El Niño events.Although small, these natural influences altered seasonal trade winds across the Eastern Pacific and affected the development of El Niño events. Interestingly, the research also showed that El Niño events in the past started later in the year and were often less intense.”We found there was a small strengthening of the regular seasonal trade winds in the Eastern Pacific in response to natural warming cycles in the Earth’s orbit around the sun. Remarkably this acted in a big way to stop El Niño events from forming and growing,” said lead author Dr Helen McGregor from the University of Wollongong.”This shows us that external factors can influence the ENSO process and that it may have a sustained response to future greenhouse gas changes. Currently 20th Century observations are too short to confirm whether this is occurring now.”Importantly, these new observations can now be used in climate models to see if these past changes in ENSO processes can be reproduced.”Currently, climate models do not agree on how El Niño may change under future global warming scenarios,” said Dr Phipps”With these new observations we can determine which models reproduce the most accurate response to changes in the global climate. This will help us to more accurately forecast the response of ENSO under future global warming scenarios.”Read more
Sep. 4, 2013 — This century, climate change is expected to induce changes in air pollution, exposure to which could increase annual premature deaths by more than 100,000 adults worldwide. Based on the findings from a modelling study published in Springer’s journal Climatic Change, lead author Dr. Yuanyuan Fang, formerly at Princeton University and now at the Carnegie Institute for Science at Stanford, urges, in the face of future climate change, stronger emission controls to avoid worsening air pollution and the associated exacerbation of health problems, especially in more populated regions of the world.Fang and her colleagues ran various present and future simulations using the Geophysical Fluid Dynamics Laboratory Atmospheric Model version 3 (AM3), one of the first fully coupled global chemistry-climate models to integrate atmospheric dynamics, chemistry and physics. An earlier version of this model was ranked among the best in the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4). The research team examined the impact of climate change on surface air quality, and how this influences global health statistics. Under a moderate climate change scenario, the simulated global surface temperature and precipitation increased by 2.7⁰C and 6 percent respectively, consistent with findings from the recent IPCC AR4 report.Climate change is believed to harm human health in a variety of ways, including through adverse changes in food production, heat stress, sea level rise, increased storm intensity, flooding and droughts, and increased incidence of vector-borne diseases. In addition, climate change indirectly impacts health by influencing concentrations of air pollutants, such as surface ozone and fine particulate matter (smaller than 2.5 micrometers in diameter), including sulphate, nitrate, fine dust particles and black carbon. These pollutants are linked with increased risks of lung cancer and respiratory, cardiopulmonary, cardiovascular and all-cause deaths.This study shows that climate change will exacerbate air pollution and associated health risks globally and especially over heavily populated and polluted regions of East Asia, South Asia and North America. The increased health risks are mainly driven by an increase in fine particulate matter under climate change. …Read more
Aug. 22, 2013 — A pair of experimental atomic clocks based on ytterbium atoms at the National Institute of Standards and Technology (NIST) has set a new record for stability. The clocks act like 21st-century pendulums or metronomes that could swing back and forth with perfect timing for a period comparable to the age of the universe.NIST’s ultra-stable ytterbium lattice atomic clock. Ytterbium atoms are generated in an oven (large metal cylinder on the left) and sent to a vacuum chamber in the center of the photo to be manipulated and probed by lasers. Laser light is transported to the clock by five fibers (such as the yellow fiber in the lower center of the photo). Credit: Burrus/NIST View hi-resolution imageNIST physicists report in the Aug. 22 issue of Science Express that the ytterbium clocks’ tick is more stable than any other atomic clock. Stability can be thought of as how precisely the duration of each tick matches every other tick. The ytterbium clock ticks are stable to within less than two parts in 1 quintillion (1 followed by 18 zeros), roughly 10 times better than the previous best published results for other atomic clocks.This dramatic breakthrough has the potential for significant impacts not only on timekeeping, but also on a broad range of sensors measuring quantities that have tiny effects on the ticking rate of atomic clocks, including gravity, magnetic fields, and temperature. And it is a major step in the evolution of next-generation atomic clocks under development worldwide, including at NIST and at JILA, the joint research institute operated by NIST and the University of Colorado Boulder.”The stability of the ytterbium lattice clocks opens the door to a number of exciting practical applications of high-performance timekeeping,” NIST physicist and co-author Andrew Ludlow says.Each of NIST’s ytterbium clocks relies on about 10,000 rare-earth atoms cooled to 10 microkelvin (10 millionths of a degree above absolute zero) and trapped in an optical lattice — a series of pancake-shaped wells made of laser light. …Read more
July 19, 2013 — Although in the late 20th century it was maintained that eating more than two eggs a week could increase cholesterol, in recent years experts have begun to refute this myth. Now, a new study has found that eating more eggs is not associated with higher serum cholesterol in adolescents, regardless of how much physical activity they do.A new study led by researchers at the University of Granada has analysed the link between egg intake in adolescents and the main risk factors for developing cardiovascular diseases, such as lipid profile, excess body fat, insulin resistance and high blood pressure.As Alberto Soriano Maldonado, primary author of the study, explains: “Health professionals traditionally insisted that eating eggs increased cholesterol levels, so in recent decades there has been a tendency to restrict intake championed by various public health organisations.”However, the most recent research suggests that increased serum cholesterol is more affected by intake of saturated fats and trans fats — present in red meat, industrial baked goods, etc. — than by the amount of cholesterol in the diet.The results of this article, part of the European study HELENA involving nine countries, demonstrated that eating larger amounts of egg is neither linked to higher serum cholesterol nor to worse cardiovascular health in adolescents, regardless of their levels of physical activity.”The conclusions, published in the journal Nutrición Hospitalaria, confirm recent studies in healthy adults that suggest that an intake of up to seven eggs a week is not associated with an increased risk of developing cardiovascular diseases,” notes Soriano.As a result, the authors suggest reviewing dietary recommendations for adolescents, although they add that it would be useful to conduct similar research on a sample group with higher egg intake.”Egg is a cheap food that is rich in very high-quality proteins, minerals, folates and B vitamins. Thus it can provide a large quantity of nutrients necessary for optimum development in adolescents,” according to the researcher.Banishing the egg mythIn 1973, the American Heart Association recommended limiting egg intake to a maximum of three per week, an idea that was accepted by health experts for years.However, although the majority of foods rich in cholesterol are usually also rich in saturated fats, a medium-size egg contains 200 milligrams of cholesterol but has more unsaturated fats than saturated fats and only has 70 calories.Read more
July 18, 2013 — Fewer women are getting married and they’re waiting longer to tie the knot when they do decide to walk down the aisle. That’s according to a new Family Profile from the National Center for Family and Marriage Research (NCFMR) at Bowling Green State University.According to “Marriage: More than a Century of Change,” the U.S. marriage rate is 31.1, the lowest it’s been in over a century. That equals roughly 31 marriages per 1,000 married women. Compare that to 1920, when the marriage rate was a staggering 92.3.Since 1970, the marriage rate has declined by almost 60 percent. “Marriage is no longer compulsory,” said Dr. Susan Brown, co-director of the NCFMR. “It’s just one of an array of options. Increasingly, many couples choose to cohabit and still others prefer to remain single.”Furthermore, a woman’s average age at first marriage is the highest it’s been in over a century, at nearly 27 years old. “The age at first marriage for women and men is at a historic highpoint and has been increasing at a steady pace,” states Dr. …Read more
June 27, 2013 — On São Miguel Island in the Azores, there used to exist a small, nocturnal bird of prey, related to the European scops owl, named Otus frutuosoi, which was very probably driven to extinction with the arrival of the first settlers in the 15th century. An international study, in which Spanish researchers participated, has for the first time identified fossils of this species endemic to the island.On 28 August 2011 researchers Juan Carlos Rando, from the University of La Laguna (Tenerife), and Josep Antoni Alcover from the Mediterranean Institute for Advanced Studies in Mallorca unearthed some small fossil bones buried not far below the ground of the Água de Pau cave (São Miguel Island, Azores, Portugal).Two years later, an article published by the journal Zootaxa has revealed that the remains found belong to an extinct species of scops owl which has been given the name Otus frutuosoi in honour of the 16th-century Azorean historian Gaspar Frutuoso.Carbon dating the fossils indicates that they are from 1,970 years ago. The hypothesis entertained by the researchers is that the arrival of human beings to the archipelago in the 15th century changed its ecosystem and caused the extinction of the species.”Humans have a history of changing island ecosystems. When humans arrived on the island mice started to appear and laurisilva — a type of humid forest — was destroyed. This surely played a large part in the extinction of the São Miguel scops owl,” Alcover explains.Scops owls are nocturnal birds of prey, and this new species in particular is phylogenetically related to the Otus scops, or European scops owl, which with a length of 20 cm is the smallest nocturnal bird of prey on the Iberian Peninsular.It is calculated that the wing surface of the Otus frutuosoi measured a maximum of 114 cm2, at least 33% less than the European scops owl, and although its legs were 11.6% longer, “the appearance of its body was more squat,” according to the experts.”The body of the extinct scops owl of the Azores was shorter and wider than that of its modern-day European relatives. Its beak was short and small, similar to that of the nightjar. Having long legs and very short wings, it must have been a very poor flyer and thus more of a land-dwelling bird,” the scientist points out.The second extinct scops owl on North Atlantic islandsA year ago, the same team of scientists documented another extinct bird of the same genus, although bigger, in Madeira: the Otus mauli.Due to its anatomical features, the scientists believe that the Otus frutuosoi was an insectivore and must have lived on the ground of the laurisilva, where it would have found food and protection.Otus frutuosoi remains have only been found on São Miguel Island in the Azores, therefore it is considered endemic to the island, although the authors do not discount the possibility of finding more fossils of the same species or other similar ones in various parts of the archipelago.”The discovery of endemic scops owls in Azores and Madeira indicates that on occasions atmospheric conditions have occurred that have dragged these birds with them. Some reached safe land, where they survived and developed in isolated conditions, and new species formed,” concludes Alcover.Read more
June 25, 2013 — A life without feelings — unimaginable. Although emotions are so important, philosophers are still discussing what they actually are. Prof. Dr. Albert Newen and Dr. Luca Barlassina of the Institute of Philosophy II at the Ruhr-Universität Bochum have drawn up a new theory. According to this, emotions are not just special cases of perception or thought but a separate kind of mental state which arises through the integration of feelings of bodily processes and cognitive contents.They describe the model in the journal Philosophy and Phenomenological Research.Earlier theories of emotionAround the turn of the 20th Century, the psychologists William James and Karl Lange proposed that emotions are nothing other than perceptions of bodily states. According to the James-Lange theory, we do not tremble because we are scared, but rather we are scared because we tremble. “This theory does not, however, consider the cognitive content of many emotions,” says Albert Newen. If a student is anxious about an exam, then he is experiencing this anxiety because he thinks, for example, that the exam is important and that he will have a blackout. …Read more
June 13, 2013 — A new statistical analysis shows the world population could reach nearly 11 billion by the end of the century, according to a United Nations report issued June 13. That’s about 800 million, or about 8 percent, more than the previous projection of 10.1 billion, issued in 2011.The projected rise is mostly due to fertility in Africa, where the U.N. had expected birth rates to decline more quickly than they have.”The fertility decline in Africa has slowed down or stalled to a larger extent than we previously predicted, and as a result the African population will go up,” said Adrian Raftery, a University of Washington professor of statistics and of sociology.The current African population is about 1.1 billion and it is now expected to reach 4.2 billion, nearly a fourfold increase, by 2100.The new U.N. estimates use statistical methods developed by Raftery and his colleagues at the UW Center for Statistics and the Social Sciences. The group’s improved fertility forecasting methods, combined with updated data collected by the U.N., were used to project the long-term consequences of the fertility change in Africa since the last population estimate two years ago.New to this year’s projection are finer-tuned statistics that anticipate the life expectancies of women and men across this century.In other areas of the world, fewer major population changes are expected. Europe may see a small decline because of fertility continuing below replacement level, and other nations around the globe may see modest increases due to longer life expectancies, Raftery said.There’s no end in sight for the increase of world population, he added, yet the topic has gone off the world’s agenda in favor of other pressing global issues, including poverty and climate — both of which have ties to world population.”These new findings show that we need to renew policies, such as increasing access to family planning and expanding education for girls, to address rapid population growth in Africa,” Raftery said.The UN gives high and low variants of its projections, assuming that women have an average of half a child more or less than the best projection. That leaves a large uncertainty, from 7 billion to nearly 17 billion, in the range for potential world population by the end of this century.By contrast, the UW research group has developed probabilities of future population levels to be coupled with best forecasts. “Our probability intervals are much tighter, ranging from 9 billion to 13 billion in 2100,” Raftery said.Global population reached 7 billion in 2011. It passed 6 billion in 1999.Read more
June 12, 2013 — In the race against climate change and ocean acidification, some sea urchins may still have a few tricks up their spiny sleeves, suggesting that adaptation will likely play a large role for the sea creatures as the carbon content of the ocean increases.”What we want to know is, given that this is a process that happens over time, can marine animals adapt? Could evolution come to the rescue?” said postdoctoral researcher Morgan Kelly, from UC Santa Barbara’s Department of Ecology, Evolution and Marine Biology. She is a co-author of the paper “Natural variation, and the capacity to adapt to ocean acidification in the keystone sea urchin Strongylocentrotus purpuratus.” The paper was published in the latest edition of the journal Global Change Biology.Easily identified by their spherical symmetry and prickly barbs, sea urchins are found on the sea floor all over the world. They are considered a keystone species, meaning their population has an important impact on the rest of the undersea ecosystem. Too many of them and their habitat becomes barren and other algae-eating species disappear; too few and their predators — including sea mammals, seabirds, and fish — lose an important food source.Due to rising carbon dioxide in Earth’s atmosphere, the oceans of the future are projected to absorb more carbon dioxide, leading to acidification of the water. The change in the ocean chemistry is expected to negatively affect the way urchins and other calcifying creatures create and maintain their shells and exoskeletons.”It gives them osteoporosis,” said Kelly. Increased water acidity would cause the levels of calcium carbonate — which the sea urchins require — to decrease. This, in turn, would result in smaller animals, thinner shells and perhaps shorter spines for the urchins.To observe the potential effects of future increased levels of carbon dioxide in ocean water, the researchers bred generations of purple sea urchins in conditions mimicking projected environment of the ocean in near the end of the century.”We exposed them to 1,100 parts per million of carbon dioxide,” Kelly said. Current CO2 levels top off at about 400 parts per million and the levels are expected to increase globally to 700 parts per million by the end of the century. In the California region, however, CO2 levels in the ocean naturally fluctuate because of cold water upwelling, a phenomenon that also brings more acidic waters.The animals were taken from two locations off the California coast — a northern site, which experiences greater upwelling, and a southern site that experiences shorter, less frequent bouts of upwelling. …Read more
June 10, 2013 — Researchers at the University of Southampton have proposed an answer to the long-running debate as to how stable the Earth system is.Earth, with its core-driven magnetic field, oceans of liquid water, dynamic climate and abundant life is arguably the most complex system in the known Universe. Life arose on Earth over three and a half billion years ago and it would appear that despite planetary scale calamities such as the impacts of massive meteorites, runaway climate change and increases in brightness of the Sun, it has continued to grow, reproduce and evolve ever since.Has life on Earth simply been lucky in withstanding these events or are there any self-stabilising processes operating in the Earth system that would reduce the severity of such perturbations? If such planetary processes exist, to what extent are they the result of the actions of life?Forty years ago James Lovelock formulated his Gaia Hypothesis in which life controls aspects of the planet and in doing so maintains conditions that are suitable for widespread life despite shocks and perturbations. This hypothesis was and remains controversial in part because there is no understood mechanism by which such a planetary self-stabilising system could emerge.In research published in PLOS Computational Biology, University of Southampton lecturer Dr James Dyke and PhD student Iain Weaver detail a mechanism that shows how when life is both affected by and alters environmental conditions, then what emerges is a control system that stabilises environmental conditions. This control system was first described around the middle of the 20th Century during the development of the cybernetics movement and has until now been largely neglected. Their findings are in principle applicable to a wide range of real world systems — from microbial mats to aquatic ecosystems up to and including the entire biosphere.Dr Dyke says: “As well as being a fascinating issue in its own right, we quite desperately need to understand what is currently happening to Earth and in particular the impacts of our own behaviour.”Pretty much whatever we do, life on Earth will carry on, just as it did for the previous 3.5 billion years or so. It is only by discovering the mechanisms by which our living planet has evolved in the past can we hope to continue to be part of its future.”Read more
June 6, 2013 — Decades of drought in central Africa reached their worst point in the 1980s, causing Lake Chad, a shallow lake used to water crops in neighboring countries, to almost dry out completely.The shrinking lake and prolonged drought was initially blamed on overgrazing and bad agricultural practices. More recently, Lake Chad became an example of global warming. New University of Washington research, to be published in Geophysical Research Letters, shows that the drought were caused at least in part by Northern Hemisphere air pollution.Aerosols emanating from coal-burning factories in the United States and Europe during the 1960s, ’70s and ’80s cooled the entire Northern Hemisphere, shifting tropical rain bands south. Rains no longer reached the Sahel region, a band that spans the African continent just below the Sahara desert.When clean-air legislation passed in the U.S. and Europe, the rain band shifted back, and the drought lessened. Related research by the UW researchers and their collaborators shows that global warming is now causing the land-covered Northern Hemisphere to warm faster than the Southern Hemisphere, further reversing the pre-1980s trend.Previous research has suggested a connection between coal-burning and the Sahel drought, but this was the first study that used decades of historical observations to find that this drought was part of a global shift in tropical rainfall, and then used multiple climate models to determine why.”One of our research strategies is to zoom out,” said lead author Yen-Ting Hwang, a UW doctoral student in atmospheric sciences. “Instead of studying rainfall at a particular place, we try to look for the larger-scale patterns.”To determine that the Sahel drought was part of a broader shift, the authors looked at precipitation from all rain gauges that had continuous readings between 1930 and 1990. Other places on the northern edge of the tropical rain band, including northern India and South America, also experienced dryer climates in the 1970s and ’80s. Meanwhile, places on the southern edge of the rain band, such as northeast Brazil and the African Great Lakes, were wetter than normal.To understand the reason, authors looked at all 26 climate models used by the Intergovernmental Panel on Climate Change. Researchers discovered that almost all the models also showed some southward shift, and that cooling from sulfate aerosols in the Northern Hemisphere was the primary cause.”We think people should know that these particles not only pollute air locally, but they also have these remote climate effects,” Hwang said.Light-colored sulfate aerosols are emitted mainly by dirty burning of coal. …Read more
May 1, 2013 — New discoveries of the way plants transport important substances across their biological membranes to resist toxic metals and pests, increase salt and drought tolerance, control water loss and store sugar can have profound implications for increasing the supply of food and energy for our rapidly growing global population.
That’s the conclusion of 12 leading plant biologists from around the world whose laboratories recently discovered important properties of plant transport proteins that, collectively, could have a profound impact on global agriculture. They report in the May 2nd issue of the journal Nature that the application of their findings could help the world meet its increasing demand for food and fuel as the global population grows from seven billion people to an estimated nine billion by 2050.
“These membrane transporters are a class of specialized proteins that plants use to take up nutrients from the soil, transport sugar and resist toxic substances like salt and aluminum,” said Julian Schroeder, a professor of biology at UC San Diego who brought together 11 other scientists from Australia, Japan, Mexico, Taiwan, the U.S. and the U.K. to collaborate on a paper describing how their discoveries collectively could be used to enhance sustainable food and fuel production.
Schroeder, who is also co-director of a new research entity at UC San Diego called Food and Fuel for the 21st Century, which is designed to apply basic research on plants to sustainable food and biofuel production, said many of the recent discoveries in his and other laboratories around the world had previously been “under the radar” — known only to a small group of plant biologists — but that by disseminating these findings widely, the biologists hoped to educate policy makers and speed the eventual application of their discoveries to global agriculture.
“Of the present global population of seven billion people, almost one billion are undernourished and lack sufficient protein and carbohydrates in their diets,” the biologists write in their paper. “An additional billion people are malnourished because their diets lack required micronutrients such as iron, zinc and vitamin A. These dietary deficiencies have an enormous negative impact on global health resulting in increased susceptibility to infection and diseases, as well as increasing the risk of significant mental impairment. During the next four decades, an expected additional two billion humans will require nutritious food. Along with growing urbanization, increased demand for protein in developing countries coupled with impending climate change and population growth will impose further pressures on agricultural production.”
“Simply increasing inorganic fertilizer use and water supply or applying organic farming systems to agriculture will be unable to satisfy the joint requirements of increased yield and environmental sustainability,” the scientists added. “Increasing food production on limited land resources will rely on innovative agronomic practices coupled to the genetic improvement of crops.”
One of Schroeder’s research advances led to the discovery of a sodium transporter that plays a key role in protecting plants from salt stress, which causes major crop losses in irrigated fields, such as those in the California central valley. Agricultural scientists in Australia, headed by co-author Rana Munns and her colleagues, have now utilized this type of sodium transporter in breeding research to engineer wheat plants that are more tolerant to salt in the soil, boosting wheat yields by a whopping 25 percent in field trials. This recent development could be used to improve the salt tolerance of crops, so they can be grown on previously productive farmland with soil that now lies fallow.
Another recent discovery, headed by co-authors Emanuel Delhaize in Australia and Leon Kochian at Cornell University, opens up the potential to grow crops on the 30 percent of Earth’s acidic soils that are now unusable for agricultural production, but that otherwise could be ideal for agriculture.
“When soils are acidic, aluminum ions are freed in the soil, resulting in toxicity to the plant,” the scientists write. “Once in the soil solution, aluminum damages the root tips of susceptible plants and inhibits root growth, which impairs the uptake of water and nutrients.”
From their recent findings, the plant biologists now understand how transport proteins control processes that allow roots to tolerate toxic aluminum. By engineering crops to convert aluminum ions into a non-toxic form, they said, agricultural scientists can now turn these unusable or low-yielding acidic soils into astonishingly productive farmland to grow crops for food and biofuels.
Other recent transport protein developments described by the biologists have been shown to increase the storage of iron and zinc in food crops to improve their nutritive qualities. “Over two billion people suffer from iron and zinc deficiencies because their plant-based diets are not a sufficiently rich source of these essential elements,” the biologists write.
The scientists also discovered transporters in plants and symbiotic soil fungi that allow crops to acquire phosphate — an element essential for plant growth and crop yield — more efficiently and to increase the uptake of nitrogen fertilizers, which are costly to produce. “Nitrogen fertilizer production consumes one percent of global energy usage and poses the highest input cost for many crops,” the scientists write. “Nevertheless, only 20 to 30 of the phosphate and 30 to 50 percent of the nitrogen fertilizer applied are utilized by plants. The remainder can lead to production of the greenhouse gas nitrous oxide, or to eutrophication of aquatic ecosystems through water run-off.”
The biologists said crops could be made more efficient in using water through discoveries in plant transport proteins that regulate the “stomatal pores” in the epidermis of leaves, where plants lose more than 90 percent of their water through transpiration. Two other major goals in agriculture are increasing the carbohydrate content and pest-resistance of crops. A recent discovery of protein transporters that move sugar throughout the plant has been used to develop rice plants that confer pest resistance to crops, the biologists said, providing a novel way to simplify the engineering of crops with high yields and pest resistance, which could lead to reduced use of pesticides in the field.
“Just as our cell phones will need more advanced technology to carry more information, plants need better or new transporters to make them work harder on existing agricultural land,” said Dale Sanders, director of the John Innes Centre in the U.K. and a corresponding co-author of the paper. “Synthetic fertilizers and pesticides are the current solution, but we can make plants better at finding and carrying their own chemical elements.”
These recent developments in understanding the biology of plant transporters are leading to improved varieties less susceptible to adverse environments and for improving human health. Says Schroeder, “More fundamental knowledge and basic discovery research is needed and would enable us to further and fully exploit these advances and pursue new promising avenues of plant improvement in light of food and energy demands and the need for sustainable yield gains.”
In addition to Schroeder and Sanders, the co-authors of the paper are Emmanuel Delhaize of CSIRO in Canberra, Australia; Wolf Frommer of the Carnegie Institution of Science; Mary Lou Guerinot of Dartmouth College; Maria Harrison of the Boyce Thompson Institute for Plant Research in Ithaca, NY; Luis Herrera-Estrella of the Center for Research and Advanced Studies of the National Polytechnic Institute in Iraputo, Mexico; Tomoaki Horie of Shinshu University in Nagano, Japan; Leon Kochian of Cornell University; Rana Munns of the University of Western Australia in Perth; Naoko Nishizawa of Ishikawa Prefectural University in Japan; and Yi-Fang Tsay of the National Academy of Science of Taiwan.Read more