Scientists use supercomputers to process models that use physics and thermodynamics-based equations covering everything from humidity in the atmosphere to sea ice formation. Climate models aren't perfect predictors, but they "are the only thing we've got," said Gerald Meehl, a climate modeler at the National Center for Atmospheric Research in Boulder, Colo. and a lead author of the IPCC report. "They're the only way we can come up with any kind of idea of what could happen."
