In The Field

AGU: ‘Is the planet really just doomed?’

Roughly a thousand people squeezed into a hall to see James Hansen talk this afternoon. They occupied all of the seats, then lined up along exterior walls. The aisles filled up with squatters, and dozens stood on tippy-toes outside trying to get a peak. At one point Mascone Center organizers forced dozens of people out, threatening to call the fire marshal and shut down the talk altogether. Then they gave up, allowing this intrepid reporter to sneak in.

There’s some rumbling within the scientific community about the way Hansen is mixing his science, as director of NASA’s Goddard Institute for Space Studies, with his activism, but clearly this has not eaten into his star power. Hansen talked about his latest research, which suggests that goals of limiting atmospheric carbon dioxide levels to 450 parts per million are too tame. He is advocating an upper limit of 350 – 35 below current levels – at a time when many are scratching their heads trying to figure out how to stabilize at 450, or even 550.

To illustrate the dangers, he talks about the “Venus Syndrome,” which is essentially runaway warming that eventually boils off the oceans and makes the planet uninhabitable. At least with a snowball earth scenario – which is, admittedly, equally bad for humanity – greenhouse gases pumped into the atmosphere by volcanoes would eventually trap enough heat to melt the ice and start the whole experiment over again. “There is no escape from the Venus Syndrome,” he says.

How close we are to the brink is not clear. “Our model blows up before the oceans boil,” he says, but the results suggest that runaway warning could be a factor of 5-20 beyond the current climate forcing.

Doomsday scenarios aside, Hansen covered a range of impacts already being felt and said even more are built into the system, which means we need to go in reverse to preserve the planet we all know and love. And that means halting the use of fossil fuels, particularly coal (for more on that, check here). He made a pitch for nuclear power and said things like biochar and better agriculture and forestry practices would enable society to pull carbon dioxide out of the atmosphere. How to get it all done? He recommends instituting a strong carbon tax and returning revenue to people on a per-capita basis in order to get them to buy in.

Sounds good. But overhauling the entire energy sector will take time, not to mention coordination with other countries. And it’s not clear which technologies can scale up how far, let alone how fast. Citing some of these problems, one questioner got right to the point: “Is the planet really just doomed?”

Pausing to let the chuckles die down, Hansen tried to put a positive spin on things. “I think we will solve the problem, but it does probably require a carbon price,” he said. “And politicians are just not willing to do that.”


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