The Rate Debate Slowing
Warming Bad - Winter Crops
Download 0.98 Mb.
|
- Navigate this page:
- Warming Bad - Yields
Warming Bad - Winter CropsIncreased viruses due to warming will devastate winter crops Roos et al. (Jonas Roos1, Richard Hopkins2, Anders Kvarnheden1 and Christina Dixelius1,1Department of Plant Biology and Forest Genetics, Uppsala BioCenter, 2Department of Ecology, Agricultural Entomology Division) 2011 (Jonas, “The impact of global warming on plant diseases and insect vectors in Sweden,” European Journal of Plant Pathology. Volume: 129 Number: 1, http://dx.doi.org/10.1007/s10658-010-9692-z, pages 7-8) //CL Warmer autumns and winters will increase the risk for insect transmission of viruses into winter crops, such as winter wheat, winter barley and winter oilseed rape. They are now sown when the number of active insect vectors has decreased significantly. Wheat dwarf virus (WDV) is transmitted in a persistent manner by the leafhopper Psammotettix alienus. Already at the beginning of the last century (1912, 1915 and 1918), a disease presumed to be caused by WDV severely affected wheat in central Sweden (Lindsten & Lindsten 1999). It has since then periodically damaged winter wheat in the central parts of Sweden. The periodic re-appearance of the disease has been associated with changes in agricultural practices (Lindsten & Lindsten 1999; Lindblad & Waern 2002). The host range of WDV includes many common grasses, and a recent study has shown that grasses growing in vicinity to WDV-affected wheat fields are infected (Ramsell et al. 2008). These grasses may act as a long-term reservoir for the virus. The leafhoppers acquire WDV from infected volunteer plants or grasses and then transmit the virus into winter wheat at the beginning of the autumn. They overwinter as nymphs and in spring, wingless nymphs transmit WDV from the infected wheat plants in the field (Lindblad & Sigvald 2004). A study in Sweden showed that the catches in autumn of adult P. alienus in fields of winter wheat increased with higher temperatures. During weeks with an average maximum temperature below 10°C only few leafhoppers were caught in yellow water traps, but during weeks above 10°C, the numbers increased with temperature, with high insect numbers noted above 15°C (Lindblad & Arenö 2002). When the crop is not infected in the autumn, the damage from WDV will be very limited. Wheat shows mature plant resistance against WDV with resistance becoming evident at growth stage DC31, when the first node is detectable (Lindblad and Sigvald 2004). Therefore, when the winged adult form of P. alienus is ready to transmit WDV between wheat fields, the wheat has already reached the resistant stage. In continental and southern Europe, winter barley is affected by the barley strain of WDV. This strain is distinct from the wheat strain infecting wheat in Sweden and other parts of Europe and Asia (Ramsell et al. 2009). There is now a risk that the barley strain of WDV may appear also in Sweden. Similar problems with autumn infection of winter crops are expected with Barley yellow dwarf virus- PAV (BYDV-PAV) and BYDV-MAV, which are persistently transmitted by different aphid species. With increased temperatures in temperate regions, disease epidemics caused by aphid- borne viruses are likely to be more severe (Jones 2009). In Germany, a clear relation was recently found between the number of infection days in autumn and BYDV-attack in winter barley fields (Habekuß et al. 2009). Warming Bad - YieldsWarming cuts into crop yields – causes price spikes Gillis (Environmental specialist staff writer for the New York Times) 2011 (Justin, “Global Warming Reduces Expected Yields of Harvests in Some Countries, Study Says,” May 5, 2011, http://www.nytimes.com/2011/05/06/science/earth/06warming.html) //CL Global warming is already cutting substantially into potential crop yields in some countries — to such an extent that it may be a factor in the food price increases that have caused worldwide stress in recent years, researchers suggest in a new study. Wheat yields in recent years were down by more than 10 percent in Russia and by a few percentage points each in India, France and China compared with what they probably would have been without rising temperatures, according to the study. Corn yields were off a few percentage points in China, Brazil and France from what would have been expected, said the researchers, whose findings were published in Friday’s issue of the journal Science. Warming kills crops & leads to price hikes – 60 billion dollars of losses Gillis (Environmental specialist staff writer for the New York Times) 2011 (Justin, “Global Warming Reduces Expected Yields of Harvests in Some Countries, Study Says,” May 5, 2011, http://www.nytimes.com/2011/05/06/science/earth/06warming.html) //CL But the authors of the study — David Lobell and Justin Costa-Roberts of Stanford University, and Wolfram Schlenker of Columbia University — pointed out that temperature increases were expected to accelerate in coming decades, making it likely that the challenges to food production will grow in an era when demand is expected to rise sharply. Over the period covered by the study, 1980 to 2008, temperatures increased briskly in many of the world’s important agricultural regions. A notable exception was the United States: for reasons climate scientists do not fully understand, temperatures in the Midwestern corn and soybean belt during the summer crop-growing season have not increased in recent decades. “One way to think of it is that we got a pass on the first round of global warming,” Dr. Lobell said. However, the study found that in virtually all of Europe, large parts of Asia and some parts of Africa and South America, temperatures during the growing season have warmed by an average of several degrees since 1980, increasing the likelihood of extremely hot summer days. The study also looked at rainfall, but changes were relatively minor compared with the temperature increases. Plants are known to be sensitive to high temperatures, especially if the hot days occur when they are flowering. “In many of these countries, a typical year now is like a very warm year back in 1980,” Dr. Lobell said. Wheat, rice, corn and soybeans account for the majority of calories consumed by the human race, either directly or as meat from animals raised on grains. Because demand for these grains is inflexible and rising, the losses from climate change probably accounted for price increases of about 6 percent in the four major commodities, the study’s authors found. At today’s grain prices, that calculation implies that climate change is costing consumers, food companies and livestock producers about $60 billion a year. “We aren’t talking about the sky falling,” Dr. Lobell said. “But we are talking about billions of dollars of losses. Every little bit of production is valuable when we’re trying to feed the world.” Their CO2 args are false – warming kills crop yields Sinclair 1/31/12 (Peter Sinclair, climate advocate, Studies: Climate Change will threaten Global Wheat Harvest, January 31, 2012, http://climatecrocks.com/2012/01/31/studies-climate-change-will-threaten-wheat-harvest/ A tired and recycled shibboleth dear to the hearts of aging climate deniers, as clueless about agriculture as they are about climate - “CO2 is good for plants…” - covered in the video above. The real world continues to provide tangible evidence of how wrong headed this is…. The Economic Times: PARIS: More intense heat waves due to global warming could diminish wheat crop yields around the world through premature ageing, according to a study published Sunday in Nature Climate Change. Nature Asia-Pacific: Extreme heat can accelerate wheat aging — an effect that reduces crop yields and is currently underestimated in most crop models — according to a study published online this week in Nature Climate Change. These findings imply that climate warming presents even greater challenges to wheat production than current models predict. An important source of uncertainty in anticipating the effects of climate change on agriculture is limited understanding of crop responses to extremely high temperatures. David Lobell and co-workers used satellite measurements of wheat growth in northern India to monitor the rates of wheat aging — known as senescence — following exposure to temperatures greater than 34 °C (93.2° F) New Scientist: In India’s breadbasket, the Ganges plain, winter wheat is planted in November and harvested as temperatures rise in spring. David Lobell of Stanford University in California used nine years of images from the MODIS Earth-observation satellite to track when wheat in this region turned from green to brown, a sign that the grain is no longer growing. He found that the wheat turned brown earlier when average temperatures were higher, with spells over 34 ºC having a particularly strong effect. [...] Lobell’s work suggests losses could be sooner and greater. “This is an early indication that a situation that was already bad could be even worse,” says Andy Challinor of the University of Leeds, UK. Meanwhile, the New York Times is reporting on a separate Indian study with similar implications. NYTimes: China and India, which constitute about 37 percent of the world’s population, face a future of sharply lower crop yields as a consequence of climate change, leading scientists in both nations warned recently. Yields from rain-irrigated wheat could drop by 44 percent by 2050 under warmer conditions forecasted by climate models, the Indian farm scientist M.S. Swaminathan told reporters during the 97th Indian Science Congress last week. Mr. Swaminathan is considered the architect of India’s “Green Revolution” for his work in the 1960s developing high-yield grain varieties that ended decades of severe famine. India continues to suffer from high inflation in food prices and widespread chronic hunger. Such problems will be vastly worse if global temperatures continue to rise, Mr. Swaminathan said. “For every one degree Celsius rise in mean temperature, the wheat loss is estimated to be of the order of six million tons per year,” he said, according to The Hindu newspaper. India’s total wheat production was about 75 million metric tons in 2009. China could face a similar climate-induced grain crisis, Zheng Guoguang, director of the China Meteorological Administration, the official weather forecasting agency in China, warned in a December essay in an influential Communist party journal. Yields of rice, wheat and corn could fall as much as 37 percent by 2050 due to increased drought conditions and other climate impacts, Mr. Zheng estimated. Citing Mr. Zheng’s essay, a statement by the Chinese Meteorological Association urged the country’s leaders to focus on adapting to, rather than mitigating, climate change. “Since climate change is an objective fact, it is more realistic and urgent for China, a big developing country, to adapt to than mitigate climate change,” the statement’s author concluded. “So China should put adaptation as top strategy of addressing climate change and put enhancing grain production and ensuring food security as first task.” Directory: files files -> Answer True False 2 points Question 2 files -> Integer programming and game theory files -> 4 Integer Programming files -> Bpa vehicle Window Repair Scenario #1 task: Procure vehicle window relacement. Objective files -> Pop Warner History files -> North Carolina Inclusion Initiative Mapping Where Children with ieps are Being Served Purpose files -> Fall 2013 Spring 2014 Program Data: Standard 1 Exhibit 4d files -> Hanban – asia society confucius classrooms network 2010 request for proposal files -> Northern England’s set-jetting locations Download 0.98 Mb. Share with your friends:
|