Report: Climate change bringing more severe weather to Minn.

Brewery Creek flooding
Brewery Creek burst through a retaining wall after heavy rains caused flooding in Duluth in June 2012.
Derek Montgomery for MPR

Global warming is rapidly turning America the beautiful into America the stormy, sneezy and dangerous, according to a new federal scientific report. And those shining seas? Rising and costly, the report says.

Climate change's assorted harms "are expected to become increasingly disruptive across the nation throughout this century and beyond," the National Climate Assessment concluded Tuesday. The report emphasizes how warming and its all-too-wild weather are changing daily lives, even using the phrase "climate disruption" as another way of saying global warming.

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Still, it's not too late to prevent the worst of climate change, says the 840-page report, which the White House is highlighting as it tries to jump-start often stalled efforts to curb heat-trapping gases.

• Read the report: President Obama's Climate Change Action Plan

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However, if the nation and the world don't change the way they use energy, "we're still on the pathway to more damage and danger of the type that are described in great detail in the rest of this report," said study co-author Henry Jacoby, co-director of the Joint Program on the Science and Policy of Global Change at the Massachusetts Institute of Technology. Jacoby, other scientists and White House officials said this is the most detailed and U.S.-focused scientific report on global warming.

"Climate change, once considered an issue for a distant future, has moved firmly into the present," the report says. "Corn producers in Iowa, oyster growers in Washington state and maple syrup producers in Vermont are all observing climate-related changes that are outside of recent experience."

The report looks at regional and state-level effects of global warming, compared with recent reports from the United Nations that lumped all of North America together.

Local impact: Climate change in Minnesota | Read more

Minnesota's location puts it directly in the midst of a Midwest negotiating the landscape of agricultural stresses and urban vulnerability that come along with climate change.

Increased heat, extreme rainfall, prolonged drought and their collective repercussions could put significant stress on existing infrastructure and regional ecosystems, the report says.

"We are likely to see reduced yields and crop failures," said J. Drake Hamilton, science policy director at Fresh Energy, a clean energy advocacy group in St. Paul. "And, in fact, the science is pointing to corn as being damaged by temperatures that exceed 90 degrees for more than a day or two."


"Increased heat wave intensity and frequency, increased humidity, degraded air quality and reduced water quality will increase public health risks."

The report says that Midwesterners can expect a longer growing season, should climate change continue along its current path. But the benefit of more crops with higher yields will be tempered by the extreme weather events that have already begun to shake Midwestern weather expectations. "In the long term, the combined stresses associated with climate change are expected to decrease agricultural productivity," the report says.

Agricultural impact

"Future crop yields will be more strongly influenced by anomalous weather events than by changes in average temperature or annual precipitation."

While the growing seasons for many crops have gotten longer over the past 60 years — a trend that will likely increase, the report says — climate change's impact on agriculture will be different from crop to crop. The yeilds from growing seasons, which come as a result of higher temperatures and elevated carbon dioxide concentrations, could be offset by the risk of springtime freezes. It's those more extreme, out-of-the-ordinary weather events — such as cold-air blasts in the springtime — that could cut the promise of longer Midwestern growing seasons short.


"Extreme rainfall events and flooding have increased during the last century, and these trends are expected to continue."

The report says Midwesterners should also brace for a series of detrimental effects from the combination of increased rainfall and infrastructures ill-prepared to deal with it:

• erosion
• declining water quality
• negative impacts on infrastructure, specifically flood control and navigation

Because Minnesota's existing infrastructure, much like its counterparts across the country, was designed with historical weather patterns in mind, it is likely not prepared, the report says, to deal with the long- and short-term impacts of climate change.

Those historical models, the report says, are "no longer appropriate guides" in preparing for future weather. The amount of heavy rainfall, for instance, has been "significantly above average" in the Midwest since 1991.

The report warns, too, of large-scale flooding "due to extreme precipitation in the absence of snowmelt." It cites the 2007 flood that poured the Root River 19 feet and the 2010 flooding across southern Minnesota as prime examples of the imminent danger — which could increase in magnitude.

Leaders worry Root River flood could dampen tourist industry (June 2008)

"Such events tend to be more regional and less likely to cover as large an area as those that occur in the spring," the report says, "in part because soil water storage capacity is typically much greater during the summer."

Flood damage
A 140-foot section of northbound Highway 169 near St. Peter, Minn., collapsed by the flooding Minnesota River in October 2010. The washed-out highway was closed north of St. Peter as MnDOT worked to restore it. A White House report on climate change, released today, pointed to the flooding as an example of what Minnesotans can expect — though with greater frequency — if climate change continues along its current trajectory.
AP/Mankato Free Press, John Cross

The big picture: Climate change on a national level

A draft of the report was released in January 2013, but this version has been reviewed by more scientists, the National Academy of Science and 13 government agencies and had public comment. It is written in a bit more simple language so people could realize "that there's a new source of risk in their lives," said study lead author Gary Yohe of Wesleyan University in Connecticut.

Even though the nation's average temperature has risen by as much as 1.9 degrees since record keeping began in 1895 — more than 1.5 degrees in the Midwest — it's in the big, wild weather where the average person feels climate change the most, said co-author Katharine Hayhoe, a Texas Tech University climate scientist. Extreme weather like droughts, storms and heat waves hit us in the pocketbooks and can be seen by our own eyes, she said.

And it's happening a lot more often lately.

The report says the intensity, frequency and duration of the strongest Atlantic hurricanes have increased since the early 1980s, but it is still uncertain how much of that is from man-made warming. Winter storms have increased in frequency and intensity and shifted northward since the 1950s, it says. Also, heavy downpours are increasing -- by 71 percent in the Northeast. Heat waves, such as those in Texas in 2011 and the Midwest in 2012, are projected to intensify nationwide. Droughts in the Southwest are expected to get stronger. Sea level has risen 8 inches since 1880 and is projected to rise between 1 foot and 4 feet by 2100.

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Since January 2010, 43 of the lower 48 states have set at least one monthly record for heat, such as California having its warmest January on record this year. In the past 51 months, states have set 80 monthly records for heat, 33 records for being too wet, 12 for lack of rain and just three for cold, according to an Associated Press analysis of federal weather records.

"We're being hit hard," Hayhoe said, comparing America to a boxer. "We're holding steady, and we're getting hit in the jaw. We're starting to recover from one punch, and another punch comes."

The report also says "climate change threatens human health and well-being in many ways." Those include smoke-filled air from more wildfires, smoggy air from pollution, more diseases from tainted food, water, mosquitoes and ticks. And then there's more pollen because of warming weather and the effects of carbon dioxide on plants. Ragweed pollen season has lengthened by 24 days in the Minnesota-North Dakota region between 1995 and 2011, the report says. In other parts of the Midwest, the pollen season has gotten longer by anywhere from 11 days to 20 days.

And all this will come with a hefty cost, the report says.

Flooding alone may cost $325 billion by the year 2100 in one of the worst-case scenarios, with $130 billion of that in Florida, the report says. Already the droughts and heat waves of 2011 and 2012 added about $10 billion to farm costs, the report says. Billion-dollar weather disasters have hit everywhere across the nation, but have hit Texas, Oklahoma and the Southeast most often, the report says.

National Climate Assessment: The Midwest

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