| September 9, 2009 |  |
Michigan to Face More Heat Waves, Flooding, and Reduced Crop Yields with Unchecked Climate Change
Congress Considering Legislation that Could Help Michigan and the Rest of the Nation Avoid Worst Consequences of Climate Change
CHICAGO (Sept. 9, 2009) — If the United States does not significantly curb heat-trapping emissions, global warming will seriously damage Michigan's climate and economy, according to a new peer-reviewed report released today by the Union of Concerned Scientists (UCS). The report found that a combination of clean energy policies—such as those currently under consideration by the U.S. Senate—would help blunt the extent and severity of global warming in Michigan and across the country.
"The Midwest climate is already changing. Over the past 50 years, we've seen higher average annual temperatures, more frequent downpours, longer growing seasons, and fewer cold snaps," said Katharine Hayhoe, an atmospheric scientist at Texas Tech University and a co-author of the report. "The likely changes documented in this report are sobering. The good news is that we can avoid the worst of them if we substantially cut global warming emissions and start doing it now."
The report, "Confronting Climate Change in Michigan," describes how the Michigan's climate could change under two scenarios: one assumes a business-as-usual increase in heat-trapping emissions from continued heavy reliance on fossil fuels, and the other assumes substantially lower emissions due to an increased reliance on clean energy sources. The report compared the two scenarios with a baseline period between 1961 and 1990.
The report found that toward the end of this century, under the higher, business-as-usual emissions scenario:
Climate: Average summer temperatures in Michigan would be hotter than 2005, the state's hottest summer of the last half century. During the report's baseline period, Detroit experienced 10 days per summer when temperatures topped 90°F and less than one day with temperatures higher than 100°F. Unchecked global warming would force the city's residents to endure nearly 65 days per summer with temperatures higher than 90°F and 23 days with temperatures over 100°F.
Detroit residents also would face an average of two heat waves per summer like the one that killed hundreds in Chicago in 1995. According to the Centers for Disease Control and Prevention, heat waves already kill more people in the United States each year than hurricanes, tornadoes, floods and lightning combined.
Agriculture: Michigan's agriculture sector, the state's second largest industry, would suffer from substantially more heat stress, which would impair livestock productivity. Michigan dairy cattle, which produced $1.5 billion worth of dairy products sold in 2007, rarely experienced heat stress during the baseline period. Toward the end of the century, Michigan dairy cattle would suffer from heat stress most summers unless kept cool in costly air-conditioned barns or by some other method.
Crop yields also would suffer. In 1988, the entire country lost $40 billion from just one heat wave -- mostly due to crop losses. That heat wave reduced corn yields in Michigan that year by more than 75 percent compared with annual average yields between 1978 and 1997. By mid-century, under the higher-emissions scenario, all Michigan summers are projected to be hotter than 1988.
Warmer winters and a growing season as much as six weeks longer than before 1990 would enable pests, such as the corn rootworm and European corn borer, to expand their range. During the baseline decades, conditions favorable to these pests occurred rarely. With unchecked global warming, by the end of this century pest infestations could happen nearly every summer.
Crop production also would be threatened by changing rain patterns, ranging from wetter springs -- which delay planting and increase flood risk -- to almost 10 percent less rain during the increasingly hot summers. Crop-damaging three- and seven-day heat waves would occur at least every other summer toward the end of the century. During the report's baseline period, three-day heat waves occurred about once a decade, and seven-day heat waves occurred only once out of 30 summers.
Extreme Weather: In June 2008, 11 Michigan counties were declared federal disaster areas after enduring severe storms that caused eight deaths and cut power to 730,000 homes and businesses. Another severe storm hit in 2009, pounding some areas with eight inches of rain overnight, causing the Grand River to flood much of Allegan and Ottawa counties. If we fail to cut global warming pollution, heavy rains would become more common throughout the year, leading to a greater incidence of flash flooding. Winters and springs, when the flood risk is already high, would become more than 20 percent wetter than during the baseline decades.
Health: If tailpipe and smokestack emissions continue at today's levels, Michigan would experience more severe smog as the number of extremely hot days increases. That would have serious consequences for public health, including a greater incidence of asthma attacks and other respiratory conditions. For example, ground-level ozone—a dangerous air pollutant and the main component of smog—increases at temperatures higher than 90°F. That is particularly bad news for the nine Michigan counties—mostly near Detroit and Ann Arbor—where ozone levels already are higher than the Environmental Protection Agency's ozone standard.
Great Lakes: As average temperatures jump more than 7oF under the higher emissions scenario toward the end of the century, Great Lakes water levels are projected to decline. This primarily would be the result of increased evaporation caused by higher temperatures and a decrease in winter lake ice. Compared with the baseline period, Great Lakes water levels are projected to fall 1 to 2 feet by the end of the century in the higher emissions scenario. Under the lower emissions scenario, little change is projected because precipitation increases would balance increased evaporation caused by higher temperatures.
In June, 13 federal agencies released a comprehensive national report using the same methodology as the UCS report released today. Like the UCS report, the federal report concluded there is still time to avoid the worst consequences of climate change.
Shortly after the national report came out, the House of Representatives passed "The American Clean Energy and Security Act," a landmark bill that would help build a new clean energy economy and launch the first national plan of action to address global warming. The bill is currently under consideration in the Senate.
"The science is clear. We have to get started now so that our children and grandchildren don't suffer from deadly heat waves, and our farmers don't have to battle more extreme droughts and floods, and more pest and weed infestation," said Ron Burke, UCS's Midwest office director. "Our report shows how critical it is for Michigan's congressional delegation to support a bill that will get America running on clean energy."
The Union of Concerned Scientists puts rigorous, independent science to work to solve our planet's most pressing problems. Joining with citizens across the country, we combine technical analysis and effective advocacy to create innovative, practical solutions for a healthy, safe, and sustainable future.
