James Hansen Asks Young People to Get Involved

(3BL Media/Justmeans) - James Hansen came to Rochester, NY to give the keynote address at the Sierra Club’s Annual Forum. The title of his talk was “Climate Change and Energy: How Can Young People Take Ownership of Their Future?” It was the culmination of several talks he had given while in town.

Not surprisingly, Hansen began by talking about how last year was the warmest on record and how based on the data recorded so far, this year is well on its way to being warmer. He described the many sources of data corroborating the phenomenon like GRACE satellite data that shows Greenland and Antarctica rapidly losing mass, and the 3,200 Argo floats that have been sampling temperatures in the top 2 km of the ocean. These show the increase in ocean temperature. Though we have had a “pause,” for about a decade, in which the rate of cooling had declined, the recent data shows the resumption of the earlier trend. The pause has been explained by Drew Shindell (a former colleague of Hansen’s) as being due to the short term impact of aerosols, among the explanations that have been put forward.

Hansen’s biggest concerns going forward are two irreversible trends. The first is the extinction of species, the rate of which is estimated to take out anywhere from 25 to 50 per cent of all species living on Earth today, by the end of the century. While climate change is not the only factor driving these extinctions, it exacerbates many of the other stresses, such as loss of habitat and chemical pollutions, which are also primarily human induced.

The second concern is disintegration of the great ice sheets. New satellite data confirms that the ice sheets of Greenland and Antarctica are losing mass at an accelerating pace. In the case of Western Antarctica, that rate of ice loss has been increasing by 25 billion tons per year per year.

He described a newly discovered positive feedback loop to add to the albedo loss, and the release of methane from melting permafrost. This one has to do with the circumpolar circulation of water in the ocean. As the glaciers melt and discharge large amounts of fresh water into the ocean it cause the cold water to sink more slowly which has the effect of causing sea ice to expand. This, in turn, releases heat that is melting the ice shelves that act as buttresses to the great ice sheets. Should the ice sheets disintegrate, ocean levels will rise by huge amounts. Even if temperatures are maintained at the 2 degrees C mark that the IPCC is currently targeting, we could still see sea levels 5-9 meters above their current levels, enough to wipe out virtually all coastal cities.

There is still room for optimism, he says, but we need to be realistic. He agrees that we need to get the atmospheric CO2 level back down to 350 ppm. To do so would require a 6% reduction per year until 2050. That’s a bit hard to imagine, consideration that carbon emissions are still increasing, though the rate of growth is slowing down. The EPA’s latest fuel economy ratings call for a 5% annual decrease in fuel consumption, which is close, though that is only a small piece of the pie.

Soil and forestry practices can make a big difference in terms of keeping carbon in the ground and out of the atmosphere. Hansen says the agreement just signed by the Department of Agriculture could potentially be huge. Other factors are also coming into play. Air pollution in places like India and China, where 10 to 20 thousand people per day are dying, is forcing officials to take more dramatic action to reduce emissions.

Here at home, we have flattened out our emissions, but we need to go negative since, much of that flattening was achieved by exporting emissions, in the form of heavy industries sent overseas. Hansen says the only way many countries will be able to meet their energy needs without carbon will be by utilizing nuclear power. This idea did not sit well with an environmentalist audience, but again, Hansen asked them to be objective.

Finally, he made a plea for a carbon pricing scheme based on the fee and dividend program, similar to the one that has been introduced in Congress several times now. The plan would place a fee on carbon based fuels at their source, and then redistribute the funds to taxpayers on an equal basis. That way, people using less energy than the average, would come out ahead, a fact that would serve as an incentive for all.

Hansen closed by saying he was encouraged by the number of young people recently attending his talks.
“Usually,” he said, “I get a bunch of old geezers.” Hopefully that’s an encouraging sign too.