Kevin Gurney, an associate professor at Purdue University, showed high-resolution animated graphics of the past, present and future of climate change at CASW's 2009 New Horizons in Science briefing at the University of Texas at Austin. Unfortunately, his pictures suggest that carbon emissions may soon look a lot worse.
Doom and gloom has never been so high-tech.
Kevin Gurney, an associate professor at Purdue University, showed high-resolution animated graphics of the past, present and future of climate change at CASW's 2009 New Horizons in Science briefing at the University of Texas at Austin. Unfortunately, his pictures suggest that carbon emissions may soon look a lot worse.
"Climate science has become the dismal science," said Gurney, who, as part of the IPCC, was a co-recipient of the 2007 Nobel Peace Prize with former vice president Al Gore.
Gurney explained that right now the oceans and forests are carbon "sinks" — absorbing about two-thirds of the carbon dioxide humans pump into the atmosphere. Those carbon reservoirs have lent a "helping hand," since the Industrial Age he says, sequestering a large portion of our fossil fuel emissions.
But as the planet warms, those reservoirs will become saturated. By mid-century, the warm ocean will stop dissolving carbon dioxide, because the gas doesn't dissolve well in warm liquids. In addition, new growth forest currently soaking up excess carbon dioxide will finish growing and take in less carbon. At that point, human fossil fuel emissions will pack a double-whammy — more carbon dioxide will stay in the atmosphere and the climate will warm even faster.
But that's not all. A hotter climate also means more trees will die from drought and wildfire, leading to carbon dioxide being pumped back out into the atmosphere. The soil will warm up, too, increasing microbial activity and releasing even more carbon. In essence, land organisms will become a growing source of atmospheric carbon dioxide.
Gurney bases his predictions on models that match seasonal temperature changes with carbon dioxide emissions around the planet. The models show that as the planet warms with the seasons, carbon is released from plants, animals and other organisms. According to Gurney, a warmed planet will cause similar carbon release, but on a much larger scale.
"That's a bummer," Gurney said. "It essentially increases the severity of the emissions problem by a factor of two."
To pinpoint sources of U.S. carbon emissions, Gurney pooled data from industry, business, and traffic for each state. The result is a highly detailed, animated map of the country's emission sources now available on Google Earth and YouTube.
He next plans to model carbon emissions on an even smaller scale — at the level of individual cities and even homes. Eventually he hopes to "zoom in" further and use social networking to get individuals' carbon footprints.
Other scientists have simulated future climate change with models that provide scenario-building capability. A 2007 paper that suggested if humans stripped all the trees in the northern latitudes, those areas would cool down. Without their dark leaves, the land surface would be brighter and more reflective, sending heat back into outer space.
But in the tropics, deforestation has the opposite effect. There, trees are the atmosphere's source of water and removing them decreases cloud cover. In that case, you lose the clouds' reflectivity and Earth's surface gets warmer.
Gurney says these results may complicate future climate change policy.
"It looks a lot like trans-boundary pollution," Gurney said, "which is very spatially variant and makes it much harder to negotiate between countries."
But, Gurney says, we shouldn't make decisions about deforestation just yet. Scientists are still working to add in other factors and run more realistic deforestation scenarios.
In the meantime, Gurney thinks we should be trying mightily to reduce our carbon emissions.
"The inertia in the system is so unbelievably profound," he said. "We need to try everything at this point...to get carbon dioxide out of the atmosphere"
Gwyneth Dickey is a graduate student in the University of California Santa Cruz Science Communication program. She is currently an intern at the Monterey County Herald in Monterey, Calif.
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