| September 9, 2009 |  |
Wisconsin to Experience More Heat Waves, Flooding and Reduced Ag Productivity if Nation Fails to Cut Climate Change Emissions, New Report Finds
Congress Considering Legislation that Could Help Wisconsin 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 Wisconsin'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 Wisconsin 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 and professor 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 that now."
The report, "Confronting Climate Change in Wisconsin," describes how Wisconsin'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 Wisconsin would be as much as 12°F higher than the baseline period. Over that 30-year stretch, Milwaukee experienced only nine 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 more than 55 days per summer with temperatures higher than 90°F and more than 22 days with temperatures over 100°F.
Milwaukee residents also would face at least one heat wave 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: The state's agriculture sector would suffer from substantially more heat stress, which would impair livestock productivity. Dairy cattle, which produce the state's most lucrative agricultural products—worth nearly $4.6 billion in revenue in 2007—rarely experienced heat stress during the baseline period. Toward the end of the century, Wisconsin dairy cattle would suffer from heat stress most summers unless they are kept cool, for example, in costly air-conditioned barns.
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 and soybean yields in Wisconsin that year by 65 percent compared with average annual Wisconsin yields between 1978 and 1997. By mid-century, under the higher-emissions scenario, all Wisconsin 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 earworm, to expand their range. During the baseline decades, conditions favorable to the corn earworm rarely occurred in the state.
Crop production also would be threatened by changing rain patterns, ranging from wetter springs—which delay planting and increase flood risk—to more than 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: 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 be 25 percent wetter than during the baseline decades.
Health: If tailpipe and smokestack emissions continue at today's levels, Wisconsin 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 eight counties in and around Milwaukee 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 Wisconsin'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.
