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Climate projections: Visualizing global warming in the round

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


BOULDER—Thin clouds of dust blow off the west coast of Africa toward the Caribbean; wisps of black carbon emissions roil over the U.S. These big-picture global chemical equations can often get lost deep in complex climate datasets. But a seemingly simple idea is helping school children and scientists alike visualize models of carbon, climate and even continental drift.

Working at home in his garage 15 years ago, Sandy MacDonald, director of the National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory, started devising a way to project animations of climate models onto a round surface. The final project, known as Science on a Sphere, now has hundreds of animated models that can play across the surface of a six-foot suspended globe, mapping everything from projected ocean acidification to global shipping routes.

"It was pretty crude," MacDonald said, recalling his early prototypes. But now, he noted, with more than 50 of the spheres set up worldwide, the whole system takes just one or two computers and four projectors to run. "It's not enough to just do the science," MacDonald said, switching model visualizations with a Wii remote.


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But nailing down the science is a crucial first step. "We know we've got to get the oceans right," MacDonald said. And one of the most simple animations drives home the unequal nature of temperature change predictions. As the years flash in the animations, the continents heat up several more degrees than do the oceans, represented as a bright, deep red. That differential, MacDonald described as the "ugly secret of global warming." Oft-cited predictions for global surface temperature increase of six degrees Celsius over the next 90 years are misleading because "they're talking about the average," rather than the more localized, severe jumps that are predicted to occur on land, where people live. By his estimate, he noted, the U.S. will experience a rise of about 10 degrees Fahrenheit by 2100, which averages out to about a degree every decade this century.

And to try to help stem the continental temperature—and sea level—rise, a more accurate tracking of carbon emissions is going to be crucial; it's "going to be absolutely essential to find who is producing it" and how it varies over season, MacDonald said. Despite the improvements in models and visualizing them, he noted, on carbon emission tracking, "we're still pretty crude."