International climate scientist visits UNC

by DeLene Beeland, February 2, 2010
Just as the snow was beginning to melt after one of the worst winter storms to hit the Triangle in recent memory passed, climate scientist James Hansen visited the Univ. of N.C. at Chapel Hill to talk about – you guessed it – global warming.

It’s probably not the first time he’s delivered a speech during wacky weather, and it likely won’t be the last –
Hansen directs NASA’s Goddard Institute for Space Studies, and he is an adjunct professor in the Department of Earth and Environmental Sciences at Columbia University. His visit to the Triangle was courtesy of UNC’s Frey Foundation's Distinguished Visiting Professor Lecture Series. Before his Monday evening lecture, Hansen met with UNC students studying climate change policy in a course taught by environmental policy professor Richard Andrews. Today, he will speak to an undergraduate class studying rivers and global change, taught by Brent McKee, professor and Chair of Marine Sciences.

Hansen has become the public face of climate change science and policy. His outspoken criticism of political solutions for limiting greenhouse gas emissions, such as cap-and-trade systems, has earned him as many friends as it has foes. In recent years, he has moved from the realm of science into advocacy, with no apologies. Perhaps most famously he was arrested on June 23, 2009, along with 31 other protesters “on charges of obstructing officers and impeding traffic during a protest against mountaintop mining,” according to New York Times reporter Andy Revkin’s post on his blog, Dot Earth. The West Virginia protest lives on at YouTube:


But his tone on Monday night was subdued. Even understated. He said the reason he has chosen to speak out so loudly is that he wants his grandkids to know that given all he understands about climate change, he tried to help the public understand, too. He wants them to know he gave it his best.

The core of his public talk focused on the now-familiar mechanics of what scientists know about climate change and how they know it. He discussed how paleo-climatology informs scientists studying modern global trends and those building models that predict future trends. He talked about long-term trends on land and in the deep ocean, and how interplanetary forces affect the Earth’s oscillations and exposure to the Sun’s light.

“There is a gap between what scientists understand and what the public knows,” Hansen said. Personally, I’d flip that around to: there is a gap between what scientists know and what the public understands (or think they know).

Looking to the past, he described a time 50 million years ago when the earth was ice free, and there were about 1,000 parts per million (ppm) of carbon dioxide (CO2) in the atmosphere. Our current levels are at about 385 ppm, dangerously near a tipping point, he said. He discussed how India colliding with Asia churned up carbonate from the seafloor, causing a massive, natural, climate-change forcing. But even this major event pales in comparison with what is in the pipeline, he says. It caused a change of only about 0.0001 ppm/yr of atmospheric CO2 [blogger's note:  see reference and link below -- a very interesting study!], whereas anthropogenic sources today are causing an increase of about 2 ppm per year.

In graph after graph, he showed upward trending greenhouse gases and temperatures. The only downward trending graph was that of the loss of mass in large ice sheets like those on Greenland and Antarctica.

“To preserve creation on this planet, similar to what civilization developed in,” humanity will need to target CO2 reductions to get to less than 350 ppm, he said. Reaching that target is a matter of great political debate and divisiveness. Hansen does not favor cap-and-trade systems and instead advocates for a fee–dividend system, which he says is “designed to benefit the public rather than Wall Street.” Under this system, fossil-fuel companies would pay a carbon fee on the first sale of oil, gas and coal at the mine, wellhead or port of entry. This fee would be divvied up to the public, monthly, deposited electronically in people’s bank accounts.

Don’t hold your breath waiting for this to materialize in the legislature, though; even Hansen admits the current political system is entrenched in trying to move cap-and-trade systems forward, although some say they likely won’t do much to decrease net greenhouse gas emissions.

The bottom line is that as long as fossil fuels are the cheapest form of energy, their use will continue and even increase, Hansen said. So he advocates for a fundamental revamping of our energy sources away from carbon-based fuels, of which coal is the dirtiest, which circles back to why this understated, eloquent and extremely smart man ended up in handcuffs last summer due to civil unrest: he was protesting mountain-top-removal mining which removes entire mountain tops to get to coal beds. Massey Energy is one of the largest companies engaged in this practice, and Hansen and other protesters were attempting to enter its property in West Virginia.

Hansen is one of the few scientists willing to step so deliberately into the public sphere, and on Monday night he drove home his conviction that the only solution to climate change is a political one driven by policy.

“We don’t have a political leader who will stand up and say, ‘This is an injustice,’ ” Hansen said.

As for the recent foul weather? Hansen says it is the result of an extreme phase of  the “Arctic oscillation” – the result a weakening of the jet stream that typically keeps Arctic air locked down around the poles, which allows frigid air to leak out and be replaced by warmer air.

“The Arctic has been warmer than normal, while it was colder than normal here,” he said. “Don’t look for this to happen again soon – it’s been three decades since we’ve seen a phase as extreme as this one.”

Link:   http://scienceinthetriangle.org/2010/02/international-climate-scientist-visits-unc/

James Hansen on David Letterman:

A Conversation with James Hansen:

Storms of my grandchildren, a book by James Hansen
NY Times Opinion Column on Cap-and-Trade system
UNC’s Powering a Nation multimedia on the energy crisis and Appalachian mountain-top-removal coal mining

Study on the production of CO2 by subduction during the colliding of India with Asia:

Proceeding of the National Academy of Sciences (October 21, 2008), 105(42),  16065–16070. Published online 2008 September 22, 2008; doi: 10.1073/pnas.0805382105.