Biophysical climate feedbacks revealed at NASW 2009
Science writers from around the country gathered in Austin this week for their annual conference, put on by the National Association of Science Writers and the Council for the Advancement of Science Writing. The meeting attracted some 300 science writers – journalists, editors, communications professionals, etc. – for several days of talking about science and the craft of writing. In the current media environment where newspapers are folding left and right, the meeting is flooded with freelance writers looking for good, newsworthy science. This year the program includes scientists from around the country giving talks on diverse topics such as using yeast to study aging, creating a unified theory of consciousness and examining scientific ethics in the peer-review process.
One of the most intriguing talks was given by Kevin Gurney of Purdue University. His project was spurred by the fact that although climate scientists are honing their understanding of the global climate cycle, the role of earths’ lands as a carbon sink is still unclear. Although Earth’s lands absorb about 3 billion tons of human-produced carbon per year, it’s tough to know where it goes. Is it mostly sequestered by vegetation? Is it captured by soils? The answers to these questions are important because if we know where the C is going, we can better predict the limits of Earth’s land’s ability to trap carbon. As Gurney says, if our lands or ocean saturate and stop sequestering carbon, that would effectively make our carbon emissions twice as bad as they are now.
Gurney’s Vulcan project attempts to map with high resolution carbon emissions across the United States. The simulation above shows these results mapped on Google Earth – you can zoom into any area and pull up a dictionary entry of its carbon emissions profile. Gurney has also taken these predictions to the next level and extrapolated for individual buildings in a pilot city – Indianapolis, Indiana. Knowing exactly where our carbon emissions are coming from will help us to figure out exactly where it’s going. Gurney hopes that in the future we’ll have an integrated climate forecasting system, just like our current weather forecasts, that will predict the carbon fluxes within any given region at any time.
But the most amazing result Gurney presented – and the reason for his talk’s title, “Some Unfortunate Surprises” – has to do with the importance of Artic vegetation for climate change. Gurney’s simulations showed that if we removed all the vegetation in the Earth’s northern latitudes, the resulting exposed snow and ice would in fact create a lighter Earth surface. This change in albedo over the following 100 years would actually reflect more of the sun’s rays, creating global cooling. Even if all the world’s forests were cleared, creating a net expulsion on carbon to the atmosphere and increasing the greenhouse effect, the whitening of the Arctic would create a net global cooling.
This thought exercise is surprising and disturbing for ecologists because it flirts dangerously with the idea that deforestation might actually counteract anthropogenic climate change. These ideas don’t take into account any other gases, nor the other ecosystem services provided by these areas that have other climate benefits, of course. But Gurney says it driven the point home that our climate change models must include biophysical feedbacks to the environment.
Learn more about Gurney’s work at the Purdue Climate Change Research Center.