MORAN - "It's showtime!" exclaimed Dr. Steven Running, professor of ecology at the University of Montana and member of the Intergovernmental Panel on Climate Change, as he spoke last month to members of the Yellowstone Business Partnership at Jackson Lake Lodge.

Running said it was time to get serious, as he urged business leaders from Wyoming, Montana and Idaho to press their senators and representatives to support the carbon cap and trade bill before Congress. Running said that he feared that if President Obama couldn't show meaningful progress by the United States at this year's world climate change meeting in Copenhagen, "then we may be in serious trouble."

Running shared the Nobel Peace Prize in 2007, as a lead author for the Fourth Assessment of the IPCC, together with Al Gore and 600 fellow scientists around the world.

"Hey, one/six-hundredth of a Nobel Prize isn't bad," he joked.

He spoke passionately about climate change, noting that science has understood the physics for over 100 years, back when Swedish scientist Svante Arrhenius first calculated in 1896 that emissions from human industry might someday bring a global warming.

"The atmosphere is very thin," said Running, compared to the bulk of the planet. "It is no thicker than from here to Jackson Hole. We're filling up a very small component of the earth system."

The principles of climate change are simple, he said. Visible light enters, but thermal energy is trapped - more so than in the past, since there is more carbon dioxide in the atmosphere, which means the global mean temperature has been rising since 1980.

The net impact of this extra energy and heat in the oceans, land mass and atmosphere, said Running, is equivalent to placing 1.6 watts - about your typical Christmas tree light - on every square meter of Earth.

"So where did that 1.6 watts of energy go?" he asked. Extra carbon dioxide and other greenhouse gases have added 1022  (10 followed by 21 zeroes) joules of energy, mostly in the world's oceans. That means there's more than enough extra energy in the weather/climate machine, to effect change for decades to come.

"This presents a difficult political problem," said Running. In order to prevent the worst effects of global climate change, society and the economy must change fundamentally, but "you'll never see the difference, as a result of our changes, in your lifetime. That's what we're stuck with. Nothing we do, good or bad, will effect quick change."

So why do anything? Because, said Running, to do nothing is to invite world-wide disaster.

Coastal flooding will affect billions of lives, he said, especially in the great coastal cities around the world. Oceans will become acidic, "like the fizz in soda pop," killing shell fish and coral reefs, Running added.

Greater heat energy in the oceans will intensify hurricanes, he said. "The number of hurricanes won't go up, but when they do spawn, the probability of getting a more powerful storm gets bigger," said Running. Weather scientists are now expecting a Category 6 hurricane within a few decades, he said - something the world has never seen before (175 mph or greater winds).

Showing satellite photos of Arctic sea ice, Running said 40 percent of summer ice is gone, leading scientists to predict an ice-free Arctic ocean in 20 years. "I get nervous about what could happen," said Running, to the world's ocean currents.

Looking closer to home, Running said the Northern Rockies are experiencing warmer winters, hotter summers and snowpacks that vanish earlier every spring. Running recently read the Lewis and Clark journals, noting with amazement that the explorers were thwarted on their way back home, by 12-foot snow drifts on Lolo Pass, in June. "That doesn't happen anymore," he said.

Running said he's alarmed by downward trends in snowpack and river flows. Factor in 2-3 Celsius warmer summers, and "I don't see how we'll have enough water to keep rivers flowing and water for irrigation in 50 years."

Yet if effective action to halt spewing carbon dioxide isn't taken soon, Running warned that by 2100, the world would see 5-6 C. warmer temperatures.

"The world is waiting on U.S. leadership," he said. Running said California already uses half the per capita electric power used by the U.S., "and California doesn't look like it is suffering."

It is well within the nation's technical ability to dramatically lower carbon emissions, he said. The only question is of political will.