Price of pollution

Gustavus Adolphus College put a physicist, a geoscientist, an engineer and an economist all in the same room and asked them how to save the Earth's environment.

They all said: Put a price on carbon dioxide.

No joke.

Make it more expensive for industry to continue spewing the greenhouse gases than not, and clean alternatives will have to follow, said the world-class scientists who gathered Tuesday and Wednesday for "Heating Up: The Energy Debate," the 43rd annual Nobel Conference at the small liberal-arts college in St. Peter, Minn.

The expert lineup had different favorites among the new technologies -- solar and wind, "biomass" fuel, "clean coal" and hydrogen-powered cars among them. But they were united on these points: If you don't believe in global warming, get over that. In fact, inject the issue into the current elections, all the way up to president. And make conservation part of your daily life -- such as switching to compact fluorescent light bulbs.

"We really are talking about a different planet if we don't do anything," said Jim Hansen, lead climate scientist at NASA's Goddard Institute for Space Studies in New York.

The audience of 6,500 rose for two standing ovations, both for men dedicated to convincing the unconvinced that the Earth is in the midst of a man-made warming.

Hansen was one, credited for sounding the alarm since the 1980s, even when his employer is unhappy with him.

The other was for Minnesota's own polar explorer, Will Steger, who came with photos of huge stretches of ice on the top and bottom of the world that he once crossed by dogsled and now are gone.

In his presentation, Hansen warned that the Earth is on course to warm by 3 degrees Celsius over the century -- enough to raise sea level by 25 meters (82 feet). Cutting gases -- the vast majority, carbon dioxide (CO₂) -- enough to drop that to 1 degree Celsius, may just avert a "tipping point," where global warming becomes self-perpetuating and beyond human control, he said.

On Minnesota's current warming path, a decade from now its summers will resemble those in Kansas today, said J. Drake Hamilton, science policy director for Fresh Energy, a St. Paul-based clean-energy advocate.

Worked for acid rain

Paul Joskow, an economist at the Massachusetts Institute of Technology, said putting a price on carbon dioxide springs from a basic motivational principle: "The rat needs to smell the cheese."

The whole system would work like this: The country caps its carbon dioxide emissions at a certain level, then deals out "pollution permits" to companies and utilities up to that cap. If anyone spills out more CO₂ than it can cover with its permits, it has to buy some from others that don't need all of theirs -- Joskow figures at about $50 per ton. It's called "cap and trade," and it makes pollution expensive and clean energy profitable.

Joskow would even give some permits to consumers, so they get a share of the wealth in this new marketplace.

The method worked before in this country, virtually eliminating the sulphur dioxide emissions behind acid rain, he said.

Corn ethanol was recognized as the only commercially viable new energy really up and running. Already 20 percent of the state's corn crop goes into ethanol production, and one in 10 service stations here carry the E85 fuel, according to industry experts. That accounts for one-fourth of all the E85 pumps in the country.

The scientists criticized corn ethanol for all the fossil fuel used in growing the corn -- including fertilizers, tractor fuel and irrigation systems -- and processing it to fuel. After all that, it comes in at just 10 to 20 percent below regular gasoline, said Steven Chu, a Nobel laureate in physics and director of the Lawrence Berkeley National Laboratory in California.

A breakthrough away

All the other energies-of-the-future at the conference are at least one breakthrough short of practical utility.

One of the most promising -- converting nonedible "biomass" such as tall grasses, plant stalks and wood chips into fuel -- is still looking for an affordable conversion process, Chu said. One avenue of exploration involves termites, whose digestive systems manage this naturally with wood, he said.

The hurdles for solar and wind energy, most environmentalists' favorites, are large-scale storage and distribution.

The technology for "clean coal" exists -- turning the old standby to a gas, generating energy, and catching all the CO₂ before it blows out the smokestack. But it's very expensive, and requires burying all that CO₂ underground, probably in old oil fields.

Cars that run on hydrogen came off as the most exciting but farthest-off alternative. The cars -- and many carmakers have demonstration models -- are powered by a fuel cell, where hydrogen and oxygen go in, and pure energy and water come out, explained Joan Ogden, co-director of the Sustainable Transportation Energy Pathways Program at the University of California, Davis. The problem is most hydrogen now is produced with fossil fuels.

The most likely future is some mix of these new technologies, the scientists said, but they warned the days of cheap energy are over.

"It's all going to increase energy prices, and anyone who tells you it isn't is lying," Joskow said.

H.J. Cummins • 612-673-4671

H.J. Cummins • hcummins@startribune.com