Substream - sub_gw_impact_crops

  1. back to all global warming and energy subjects

  2. 29-09-2003 eco nws - global warming - impact - crops - usa food production - Falling crop production resulting from extreme weather events, diseases and pest infestations increasingly will be fueled by global warming and create an uncertain future for U.S. agricultural production and the nation's food supplies, according to leading experts gathered here today at a Harvard Medical School Center for Health and the Global Environment briefing, made possible by the Civil Society Institute, the Energy Foundation and the National Environmental Trust. A news media event was followed by a congressional staff briefing sponsored by Sen. Harkin (D-IA), Sen. Brownback (R-KS), Sen. Bill Nelson (D-NE) and Sen. Lugar (R-IN). (seedquest)

  3. 30-06-2004 eco nws - global warming - impact - crops - rice yields strongly affected - Gobal warming could be bad news for one of the world's most important crops. It says an average daily temperature increase of 1 degree Celsius results in a 10 percent reduction in the rice crop. It says an average daily temperature increase of 1 degree Celsius results in a 10 percent reduction in the rice crop, reported Wednesday's CRI online. Funded by the International Rice Research Institute and the University of Nebraska, it shows increased nighttime temperatures are associated with significant declines in rice yields. (crienglish.com)

  4. 24-09-2004 eco nws - global warming - impact - crops - japan's rice yields at risk - Global warming poses a threat to Japan's future rice crops and thus its food security, a Japanese agricultural research group warned Wednesday. If farming methods are left unaltered, Japan's rice harvest will fall by 10 percent by 2090 as a result of global warming, according to the group. Researchers at the National Institute for Agro-Environmental Sciences in Tsukuba, Ibaraki Prefecture, project that while harvests will increase in colder regions such as Hokkaido, the national average will fall by 10 percent. (japan times)

  5. 27-04-2005 eco nws - global warming - impact - crops - reducing crop yields - Climate Change Poses Threat to Food Supply, Scientists Say - Worldwide production of essential crops such as wheat, rice, maize and soya beans is likely to be hit much harder by global warming than previously predicted, an international conference in London has heard. The benefits of higher levels of the main greenhouse gas, carbon dioxide, will in fact be outweighed by the downsides of climate change, a Royal Society discussion meeting was told yesterday. It had been thought that the gas might act as a fertiliser to increase plant growth. Rising atmospheric temperatures, longer droughts and side-effects of both, such as higher levels of ground-level ozone gas, are likely to bring about a substantial reduction in crop yields in the coming decades, large-scale experiments have shown. The two-day meeting, entitled Food Crops in a Changing Climate, is focusing largely on tropical countries where most of the world's food is grown, and where people are most vulnerable to climate change. (earth hope)

  6. 27-05-2005 eco nws - global warming - impact - crops - VN: opwarming aarde bedreigt voedselproductie - ROME (ANP) - Door opwarming van de aarde dreigt in ontwikkelingslanden een afname van de hoeveelheid grond die geschikt is voor landbouw. Daardoor zal het aantal mensen dat honger lijdt, dramatisch stijgen, waarschuwde de VN-organisatie voor voedsel en landbouw (FAO) donderdag in een rapport. Volgens de FAO geldt de dreiging voor ongeveer veertig arme landen, die samen twee miljard inwoners tellen. In die landen wonen nu al 450 miljoen ondervoede mensen en dat aantal dreigt explosief te stijgen, aldus het VN-orgaan. In het deel van Afrika onder de Sahara lijken de hardste klappen te gaan vallen. (spits)

  7. 05-12-2006 eco nws - global warming - impact - crops - india - system - atmosphere - co2 - pollution - Pollution 'reducing rice harvest' - Pollution-laden clouds may be partly to blame for India's dwindling rice harvests, according to research. A US team found brown clouds, which cloak much of South Asia, have a negative impact on rice output by reducing sunlight and rainfall. They discovered elevated levels of greenhouse gases also reduced yields. The study, reported in Proceedings of the National Academy of Sciences, came a day after researchers said new crops adapted to a warmer climate are needed. Since the 1980s, India has faced ever-declining growth rates in harvests of its staple food, raising concerns that shortages could occur. To investigate the cause, researchers looked at the impact of the 'brown clouds' or 'Asian haze' which cover the region. South Asia has one of the most widespread atmospheric brown clouds on the planet. These layers of air pollution, which contain soot and other fine particles, are primarily created from burning fossil fuels and other organic matter. The clouds interfere with the local climate by blocking the Sun's radiation from reaching the ground, leading to cooler and dimmer conditions. Recent research has revealed the polluted haze can also reduce rainfall. Using climate models and historical data on Indian rice harvests, the team built up a picture of the brown clouds' effect on rice growth over the years. 'We found if there had been no atmospheric brown clouds between 1985 and 1998, the annual rice harvest yield would have been 11% higher than it was,' said Maximilian Auffhammer of the University of California at Berkeley. The team concluded the clouds had a negative effect on rice yields. He said while the cooler night-time temperatures caused by the clouds were beneficial for the rice, the negative impact of the decreasing rainfall outweighed these benefits. Yields would also have been higher under lower concentrations of greenhouse gases, the researchers found. Many researchers, Dr Auffhammer told the BBC News website, had been worried that reducing brown clouds could boost temperatures and so further diminish rice yields. This was because previous research found the clouds' cooling properties can mask the heating effect of greenhouse gases. But, he said, the team's findings revealed that reducing clouds alone or with reductions in greenhouse gases would benefit rice output. (bbc)

  8. 18-06-2010 eco nws - global warming - impact - crops - Climate Change Threatens Food Supply of 60 Million People in Asia - ScienceDaily (June 18, 2010) � According to an article by three Utrecht University researchers published in the journal Science on 11 June, climate change will drastically reduce the discharge of snow and ice meltwater in a region of the Himalayas, threatening the food security of more than 60 million people in Asia in the coming decades. The Indus and Brahmaputra basins are expected to be the most adversely affected, while in the Yellow River basin the availability of irrigation water will actually increase. More than one billion people depend on the meltwater supplied by the Indus, Ganges, Brahmaputra, Yangtze and Yellow River. The snow and ice reserves situated upstream are important in sustaining the availability of water downstream. Researchers from Utrecht University and FutureWater have calculated the reduction in glacier and snow coverage and forecasted the future river discharge and made predictions about food security in the basins of these five major rivers. - How important is meltwater? - "The role of meltwater in the Indus basin is much more significant than that in other river basins in Asia," according to Walter Immerzeel, hydrologist at Utrecht University and FutureWater. "The downstream sections of the Indus are dry, are home to one of the largest irrigation networks in the world and are completely dependent on meltwater." - Food production - Climate change will ultimately result in declining discharge levels of the major Asian rivers, impacting the volume of irrigation water available. "Our model calculations show that the Brahmaputra and Indus are the most vulnerable. According to our estimates, this will threaten the food security of the approximately 60 million inhabitants of these areas by the year 2050," explains Immerzeel. "However, the opposite is also possible. In the Yellow River basin, an increase in wintertime rainfall is expected, resulting in increased availability of water early in the growing season." - Uncertainty about glaciers - The size and discharge of Himalayan glaciers are experiencing significant decline due to climate change. "However, observed glacial decline varies greatly from region to region, and there is a high degree of uncertainty regarding the speed of decline," says Marc Bierkens, hydrology professor at Utrecht University. "However, the trends identified in the river discharge forecast do not take this uncertainty into account." The researchers based their results on a combination of hydrologic models, climate forecasts from five different climate scenarios, and satellite images depicting snow and ice, rainfall, and changes in the Earth's gravitational field.

  9. 22-02-2011 eco nws - global warming - impact - crops - food safety - Climate Change Affecting Food Safety - ScienceDaily (Feb. 22, 2011) � Climate change is already having an effect on the safety of the world's food supplies and unless action is taken it's only going to get worse, a Michigan State University professor told a symposium at this year's meeting of the American Association for the Advancement of Science. Ewen Todd, an MSU professor of advertising, public relations and retailing, organized a session titled "How Climate Change Affects the Safety of the World's Food Supply" at which several nationally known experts warned that food safety is already an issue and will worsen unless climate change is confronted. "Accelerating climate change is inevitable with implications for animal products and crops," said Todd, who also is an AAAS Fellow. "At this point, the effects of climate change on food safety are poorly understood." However, Todd said there are already a number of examples of climate change taking its toll on the world's food supply. One is Vibrio, a pathogen typically found in warm ocean water which is now becoming more common in the north as water temperatures rise. "It's been moving further up the coast these past few years," he said. "There was an outbreak of it near Alaska in 2005 when water temperature reached 15 degrees Celsius." Todd also said that extreme weather -- droughts and heavy rains -- is having an impact on the world's food supply. In some areas crops are being wiped out, resulting in higher prices and other issues. "Mycotoxins are molds that can sometimes cause illness in humans, and where you have drought and starvation there can be a mycotoxin problem," he said. "That's because people will store their meager resources of crops for longer than they should."

  10. 05-10-2011 eco nws - global warming - impact - crops - soil - Rethinking Connection Between Soil as a Carbon Reservoir and Global Warming - ScienceDaily (Oct. 5, 2011) � Soils store three times as much carbon as plants and the atmosphere. Soil organic matter such as humus plays a key role in the global carbon cycle as it stores huge amounts of carbon and thus counters global warming. Consequently, the Kyoto Protocol permits the signatory countries to count soils and forests against greenhouse gas emissions as so-called carbon sinks. Exactly why some soil organic matter remains stable for thousands of years while other soil organic matter degrades quickly and releases carbon, however, is largely unknown. The explanatory models used thus far assume that the degradation rate depends on the molecular structures of the soil organic matter. An international team of 14 researchers headed by Michael Schmidt, a professor of soil science and biogeography at the University of Zurich, has now revealed that numerous other factors affect the degradation rate of soil organic matter in an article published in Nature. - Soil environment determines degradation rate of humus - "The degradation speed isn't determined by the molecular structure of the dead plant debris, but by the soil environment in which the degradation takes place," says Schmidt, summing up the new results. For instance, the physical isolation of the molecules, whether the molecules in the soil are protected by mineral or physical structures and soil moisture influence the degradation rate of soil organic matter. Furthermore, the researchers are able to show that, contrary to the scientific consensus, there is no humic matter in the soil and this should therefore not be used for models. - New experiments and models needed - As Professor Schmidt explains, the findings need to be used for new experiments and models. In doing so, it is not only the first few centimeters of the soil that should be examined, as has been the case up to now, but rather the full top two to three meters. In their article, the researchers make various suggestions as to how the models for forecasting the response of soils to changes in the climate, vegetation and land use might be improved. Moreover, the new results cast a critical light on bioengineering experiments with plants containing high amounts of lignin or plant charcoal (biochar), with which more carbon is supposed to be stored in the soil in the long run.