Science made a comeback at the State Capitol on Tuesday.

Five of Minnesota's most prominent researchers on agriculture, land use, weather and climate change gave a room packed with legislators a quick but sweeping summary of the global environmental problems facing the state. They touched on floods, drought, massive thunderstorms, a changing forest, invasive bugs and rising demand for groundwater.

The point, Reps. Jean Wagenius and Alice Hausman said, is that the DFL-controlled House intends to base new laws and policy decisions -- especially those related to climate change -- on research rather than dogma.

"It's science vs. ideology," said Hausman, a DFLer from St. Paul and chairwoman of the House Capital Investment Committee, describing a debate that is going on nationally as well. "There are still some that question the science."

It was the first of five joint committee hearings on looming environmental issues scheduled between now and the end of January. The others will focus more narrowly on groundwater, changes in infrastructure to handle extreme weather events and air pollution.

Wagenius, chairwoman of the House Environment Committee, said Tuesday's hearing was designed to give legislators the big perspective "at a graduate level" on the connections between climate change and the way Minnesotans use their natural resources through agriculture, water demand and forestry.

But some in the room questioned the premise.

"There is science and experts, and then there is political debate," said Rep. Joe McDonald, R-Delano. "And one side questions the authenticity of global warming. How do you know, if we are looking at only 200 years?"

New highs and new lows

The hearing came on the same day that the U.S. National Oceanic and Atmospheric Administration announced 2012 was the 10th-warmest year globally since 1880 and the 36th in a row with an annual temperature above the 20th-century average. This century's 12 years all rank among the 14 warmest on record. Last year was the warmest on record across the United States and third-warmest for Minnesota.

Mark Seeley, University of Minnesota climatologist, used complex charts and graphs to explain that it is not the change in weather trends alone that threatens disastrous consequences -- it is the pace of change. Temperatures might rise faster than people or nature can adapt, Seeley said.

For instance, he said, the huge storms that caused damaging floods in Duluth in June resulted in the largest discharge of water recorded from the St. Louis River. Yet five months later the St. Louis River also recorded its lowest discharge.

And though the big storms dump enormous amounts of water on the land, they are so intense that much of the water runs off before it can soak into the ground and into the aquifers. That, combined with drought in some parts of the state, is creating significant problems for farmers, Seeley said.

"Many of our soil moistures are at the lowest levels we have ever recorded," he said.

The changes also raise critical questions about water use in Minnesota -- a "headwater state" that gets all its water from the sky in the form of rain and snow.

That's both good and bad, said Harvey Thorleifson, director of the Minnesota Geological Survey. "We have control over it, but we are vulnerable to drought," he said.

Looking to solutions

But there are solutions as well. Bonnie Keeler, a University of Minnesota graduate student who studies the economics of land use, said conservation efforts in the right place can pay enormous dividends in protecting water, development, recreation and health. "The benefits are greater than the costs," she said.

Nick Jordan, a U professor of agronomy and plant genetics, told the committees that agriculture can help reduce Minnesota's greenhouse-gas emissions through development of biofuels. He also described a new type of crop called pennygrass that farmers could plant after harvesting soybeans; it holds water and soil on the land, provides critical forage for bees, and could boost profits by $300 per acre.

Peter Reich, a forestry professor, said that though it's impossible to predict how or how quickly Minnesota's northern forests will change, it could be possible to move in warmer-species trees, native to places like Iowa, to establish a different but more resilient woods.

"We have to realize we've already messed with nature. And nature may not fix itself," he said.

But even those who accept the science said it doesn't solve the daunting political problem of climate change. "I don't have an answer for my colleagues who see this as a natural event," said Rep. John Benson, DFL-Minnetonka.

Nevertheless, the climate challenges must be faced, said Rep. Kim Norton, DFL-Rochester, even if only "in bites."

"Can we handle the whole of climate change? No," she said. "But we can take factual research and move on that. We'd be irresponsible if we didn't."

marcotty@startribune.com • 612-673-7394 mcaul@startribune.com • 612-673-7646