In the coming decades, climate change will lead to more frequent and more intense Midwest heat waves while degrading air and water quality and threatening public health. Intense rainstorms and floods will become more common, and existing risks to the Great Lakes will be exacerbated.
Those are some of the conclusions contained in the Midwest chapter of a draft report released early this year by the federal government that assesses the key impacts of climate change on every region in the country and analyzes its likely effects on human health, water, energy, transportation, agriculture, forests, ecosystems and biodiversity.
The weekly report of the U.S. Drought Monitor released for May 7, 2013 didn't show much improvement for a profoundly parched Texas.Texas Gov. Rick Perry has watched first hand the ravages of a warming climate, first as Texas agriculture commissioner, then as governor.
However, Perry and Republicans in the state legislature argue that climate science is a made up liberal lie. Perry said it's “all one contrived phony mess that is falling apart under its own weight” in his book, Fed Up.
Republicans dismiss worsening killer droughts and record heat seen in 1996, 1998, 2002, 2003, 2005, 2006, 2008, 2009, 2010, and 2011, with July 2011 Texas’ hottest in history, so far. Last year, Texas suffered through another historic dry spell . Large sections of the state continue to experience long-term exceptional or extreme drought. These prolonged, dry conditions put a strain on water supplies for all uses.
Texas has only received 68 percent of its normal rainfall, and reservoirs are at their lowest levels since 1990. The state temperature has increased on average by about 2 degrees Fahrenheit since the 1970s, and so that impacts drought through evaporation and loss of water from the ground and reservoirs.
Projections for regionally averaged temperature increases by the middle of the century, relative to 1979-2000, are approximately 3.8 degrees Fahrenheit for a scenario with substantial emissions reductions and 4.9 degrees for the current high-emissions scenario. Projections for the end of the century in the Midwest are about 5.6 degrees for the low-emissions scenario and 8.5 degrees for the high-emissions scenario, according to the report.
The rate of warming in the Midwest has accelerated over the past few decades, according to the report. Between 1900 and 2010, the average Midwest air temperature increased by more than 1 degree Fahrenheit. However, between 1950 and 2010, the average temperature increased twice as quickly, and between 1980 and 2010 it increased three times as quickly.
The warming has been more rapid at night and during the winter. The trends are consistent with the projected effects of increased concentrations of heat-trapping greenhouse gases, such as carbon dioxide released by the burning of fossil fuels.
In the Midwest, extreme rainfall events and floods have become more common over the last century, and those trends are expected to continue, causing erosion, declining water quality and negative impacts on transportation, agriculture, human health and infrastructure, according to the report.
Certain regions are projected to heat up even sooner. In Texas and Oklahoma, the draft report doubled the probability of extreme heat events. Nighttime temperatures in will remain high in those and other southern states during the hottest summer months, providing little respite from the heat. Those extreme temperatures would also exact a toll on public health, with worsening air pollution, and on infrastructure, buckling roads and more. The constant 24 hour demand for air conditioning will stress Texas' aging power plants and antiquated power transmission system.
In agriculture, longer growing seasons and rising carbon dioxide levels are likely to increase the yields of some Midwest crops over the next few decades, according to the report, though those gains will be increasingly offset by the more frequent occurrence of heat waves, droughts and floods. In the long term, combined stresses associated with climate change are expected to decrease agricultural productivity across the Midwest, including Texas and Oklahoma.
As of November 6, 2012, 59.5 percent of the contiguous U.S. was experiencing persistent drought conditions that are most severe in the Great Plains — North and South Dakota, Nebraska, Kansas, Oklahoma, Texas, Montana, Wyoming and Colorado where drought is expected to persist or intensify in the foreseeable future. In mid-October 2012 drought conditions combined with high winds to create a large dust storm across Colorado, Nebraska, Kansas, Oklahoma and Wyoming, closing major highways.
Katharine Hayhoe, professor and director of the Climate Science Center at Texas Tech University in Lubbock, said in a Scientific American article that persistent drought will significantly impact agriculture on the Great Plains. "In a nutshell," Hayhoe said, "we're seeing major shifts in places and times we can plant, the types of crops we can grow and the pests and diseases we're dealing with. If you talk to seed companies, the U.S. Department of Agriculture (USDA) and even farmers, they tell you we can modify our way out of this, that we can overcome all these problems with technology. There's no question we can adapt to some of the change, but whether we can adapt to all of it is a very open question."
Hayhoe stresses. "There are techniques being developed already, such as dry-land farming, rotating crops and using waste as biofuel that will keep the economy going." Actions also can be taken at the local level to reduce the vulnerability of agriculture, she says, including using energy more efficiently and developing sounder management and development policies.
The drought conditions in Kansas, Colorado, Oklahoma, and Texas, which produce about a third of the country’s wheat crop, which continue into mid-January 2013 are virtually the worst on record, according to the US Drought Monitor. The Obama administration declared large areas of all four states a natural disaster area in early January, because of the persistent drought. In Kansas, America's literal bread basket state being the biggest wheat producer, the entire state is in severe drought. Oklahoma, over the last 60 days, has seen only a small fraction of its typical rainfall. David Simeral, a scientist at the Western Regional Climate Center, said “Oklahoma has really been just bone dry,” in the centers drought report last week.
American farmers must prepare for climate change with government agricultural policy leading the way. But current government agricultural policy, instead of preparing the American agricultural industry to be more resilient to the challenges of climate change,is actually taking us in the opposite direction.
The U.S. House Science and Technology Committee should focus its hearings on the need to end government mandates for corn ethanol and on once again tying crop insurance to land conservation and dry-land farming, on water conservation and reclamation technology, and alternative energy technologies for example. But that kind of science committee agenda would require the committee chair to believe that the climate change reports of thousands of scientists around the world represents factual science, not elitist liberal propaganda.
The draft National Climate Assessment report is available at http://ncadac.globalchange.gov. A summary of associated technical input papers is available at www.glisa.umich.edu.
Climate scientists predict future with lower average rainfall
No comments:
Post a Comment