Des Moines Register: Global Climate Change - What It Means to Iowa?

Sunday, May 11, 2008


Iowa's greenhouse gas emissions are growing faster than the nation's as a whole, even as new state programs fight to limit the damage from global climate change, a new report shows.

The study conducted for Iowa's Climate Change Advisory Council found that the state faces a tough task in cutting greenhouse gases, said Jerald Schnoor, an environmental engineering professor at the University of Iowa who is leading the panel.

The gases, which include water vapor, carbon dioxide and ozone, trap heat that otherwise would escape into the atmosphere. That warms the globe, threatening an increase in disease, heat-related deaths, severe weather and crop damage.

Interactive graphic: How climate change could affect Iowa

The study by the Harrisburg, Pa.-based Center for Climate Strategies found gross emissions of the gases in Iowa rose approximately 20 percent from 1990 to 2005, while the country's emissions rose 16 percent. Iowa's emissions accounted for 1.7 percent of the U.S. total in 2005.

"We're increasing rapidly, more than a percent a year," said Schnoor, co-director of the U of I's Center for Global and Regional Environmental Research. "When can we begin to reduce? That's the challenge."

Experts say the new findings - and other recent research from across the globe - paint a clearer picture of what Iowa and the rest of the Midwest will be like by the end of the century. They also bring urgency to a number of policy decisions that could hurt or help the problem.

"People are more worried," said Eugene Takle, an atmospheric science professor at Iowa State University who studies climate change.

Among the most imminent issues: two highly contentious plans for new, large coal-burning power plants in Marshalltown and Waterloo.

Iowa gets most of its power from coal plants. Critics say the proposed plants would increase emissions, while backers argue new, more efficient plants would replace older, more polluting ones. The Marshalltown plant won approval from the Iowa Utilities Board last month, but still needs a state air permit; the Waterloo plant proposal hasn't been reviewed yet.

But coal usage is only one in a long list of climate-change-related issues facing the state. Climate change could affect how farmers grow corn; how much Iowans pay for heat and air conditioning; whether we have enough water, or too much; whether we can preserve wildlife, natural areas and water quality; and whether more climate-friendly businesses can be found to drive the state's economy.

Agriculture has long been blamed for having a major role in Iowa's carbon footprint. The state is the nation's top producer of corn and hogs, and has the second-highest greenhouse gas emissions from agriculture in the country, according to the World Resources Institute.

However, growing sectors of Iowa's economy are also to blame. And even newer "green energy" contributes to greenhouse gases. For example, the Clipper Windpower turbine-making plant in Cedar Rapids has 40 suppliers, all of whom have their own emissions, Schnoor said.

Schnoor and his colleagues are looking for new ways to tackle the problem. They expect in the next month to finish a study of how much carbon is swept from the atmosphere by soil and plants in the eastern United States, including Iowa. With that information, researchers and policymakers can focus on cutting the remaining carbon.

Schnoor said the Iowa task force is also looking for ways to cut emissions while creating jobs in more climate-friendly industries.

"If we do this smart, we will create green jobs, improving the economy and cutting greenhouse gases," Schnoor said. "We're not doing that yet."

At Iowa State University, water-quality authority John Downing discovered another tool: farm ponds and small lakes. Combined, those waterways cover twice as much area as previously thought, and could sink more carbon annually than oceans, Downing found.

Several themes emerge when the new state research is mixed with cutting-edge studies from the Intergovernmental Panel on Climate Change - a worldwide network of experts on climate change - as well as other researchers. Although they disagree on some points, here's what most say the state can expect:


Longer growing season could affect crop yields

New software models projecting the future show Iowa faces big changes in the next 50 years - and even more in the remainder of the century.

Expect significant changes to the state's growing season, because the new research suggests Iowa will gradually go through more heat spells and torrential rains, Takle said.

Climate change already has added an inch of rain to Iowa's supply in each of the past several decades, made the state a more humid place, and ramped up some storms. Winters are generally warmer, and wetter conditions have shaved a few degrees from summer's peak temperatures - both signs of climate change, Takle said.

Over the next century, the warmer, wetter weather will result in Iowa's climate becoming more like that currently associated with Kansas, and, eventually, like Arkansas or Mississippi.

Scientists have noted for years that more carbon dioxide, which feeds plants, will likely mean booming crop yields. Takle said the longer period between the spring thaw and the return of frost in winter could mean longer growing seasons.

The changes could open the door for farmers to grow two, maybe even three, crops a season, Takle said. "It's not all gloom and doom. We should be thinking of what opportunities will be presented by climate change. China is already double-cropping."

The Intergovernmental Panel on Climate Change predicts rain-fed agriculture in North America could see a boost in crop yields by as much as 5 percent to 20 percent in the next few decades.

But weather and climate changes could dampen the gains, according to the panel's latest report.

For example, crop yields could drop 40 percent by 2100 because of higher levels of ground-level ozone, a key part of smog made up of oxygen, according to a team from the Marine Biological Laboratory in Woods Hole, Mass., and the Massachusetts Institute of Technology.

"Ozone has a hugely detrimental effect of crops," said Ben Felzer, an MBL research associate.

Even though there could be big declines in crop yields, the MBL and MIT scientists are forecasting a drop of only 9 percent in food production in the next century, because farmers would use more land for crops.


Heat poses new threats to health, human life

Iowans can count on more weather-related deaths due to higher temperatures and longer heat spells.
The science behind the rising temperatures:

Moisture in the air will likely increase because water vapor is the most prevalent greenhouse gas. Over time, this results in higher temperatures day and night.

More moisture in the air means better photosynthesis for crops, which wouldn't have to draw as much moisture from the soil.

"That may be favorable for corn, but people might not like it as much," Takle said.

As a result, people living in the Midwest will struggle with more heat waves, according to the international panel and a Pew Center on Global Climate Change report in December 2007.

Consultants at the National Center for Atmospheric Research found more frequent heat spells in all versions of a model used to predict the climate in Chicago, St. Louis and Cincinnati from 2080 to 2099.

On average, the frequency of heat waves for all three cities increased by 36 percent. The duration of those heat waves increased by 27 percent in the models.

Consequently, that will be a health threat. Iowa will continue to have a relatively old population, but it does not have a full disaster plan to handle the type of deadly heat waves that hit Chicago in 1995, killing 600, and France in 2003, killing 14,800, Takle said.

Higher concentrations of ground-level ozone are expected to harm human lungs, in addition to suppressing plant growth. The Midwest would see some of the greatest damage from the higher levels.

The shift in climate also will prompt longer seasons for ragweed and other allergens, according to Stanford University researchers.


Water shortages, more drought possible despite heavier rains

Warming might make water shortages a bigger issue in Iowa, where a boom in ethanol plants and hog confinements have already strained supplies.

The international panel and other scientific teams have predicted greater evaporation of precipitation and more drought, which could sap water from rivers, lakes and underground supplies.

More intense rains could fuel floods and worsen the condition of Iowa rivers that are already high in fertilizer pollution, Takle said.

Iowa already has more rain than it did 25 years ago, most of it from severe weather events. The chances of downpours of 2 inches or more will rise over the coming decades, Takle said.

"More rain tends to be favorable because we tend to be a bit dry," Takle said. "But in a heavy rain, the extra inch tends to be runoff, which would lead to more pollution issues" and less water soaking into the ground.

Takle said summer temperatures in Iowa have dropped over the past three decades. Rainfall is up, which adds to soil moisture. The sun then evaporates water from the soil, and there is less energy from the sun to heat the air. That keeps temperatures down.

But the international panel and others predict more drought, too, due to the disruption of weather patterns.

The variable water supplies will mean one more challenge for agriculture.

"The seed corn companies have made remarkable progress in breeding in drought tolerance," Takle said. "The seasonality will be an issue. When does the rain come?"


Milder winters would affect environment, infrastructure

Milder temperatures could mean savings on home-heating bills, Takle said. It also could provide more groundwater recharge in periods of fast snowmelts. On the down side, look for more freeze-thaw cycles, damaging roads and bridges and altering growing seasons.

"That has a variety of ramifications that we really don't know," Takle said.

Fickle weather last year illustrated the potential for trouble, Takle said. In April 2007, a hard freeze followed an unusually warm period in March. That caused heavy damage to tree buds and fruit blossoms.

"It just zapped everything," Takle said. "I looked at a satellite map of plant productivity for the spring season of 2007. It showed a big hole in the middle of the country."

Many trees never did recover to a normal rate of producing leaves and branches. That two- or three-day event disrupted the whole carbon uptake in the middle of the country for the entire season, he said.

Takle said his research suggests temperatures overall are rising - but winter temperatures in Iowa are increasing the most. Average winter temperatures have climbed 1 degree Fahrenheit per decade.


Wildlife to feel warming's impact; pest population could grow

The Union of Concerned Scientists predicts Iowa stands to lose at least 36 bird species, but gain 10 new ones by the end of the century.

The Intergovernmental Panel on Climate Change predicts that between 20 percent and 30 percent of Earth's species are at an increased risk of extinction if average temperatures increase more than 2.5 degrees Celsius.

The panel also expects fewer neotropical migrants in North America. Those are the tiny songbirds that now frequent Iowa in the summer, migrating from Mexico and other Latin American nations.

The Eastern goldfinch, the state bird, may move out of state, to the north, the National Wildlife Federation reports.

Deer, skunks and raccoons could benefit from a smorgasbord of new plant growth in places, but they might spread rabies and other diseases farther.

Denison native James Hansen, director of NASA's Goddard Institute for Space Studies and a leading climate researcher, said the next 50 years promise to bring more crop- or tree-damaging pests up from Southern states.

Other scientists expect warming to mean a wider risk of Lyme disease and other illnesses carried by ticks or mosquitoes.

Trout, which are found in northeastern Iowa, might not be able to survive warming waters, and other species are likely to shift their range to the north.

Takle said predictions for the latter half of the next century are somewhat less certain. He and other scientists continue to adjust computer models.

What they find will affect far more than their latest scientific papers, say Takle, Hansen and other climate scientists. Iowans' health, economy and quality of life are riding on those results, and how people respond to them.