The factors that may be contributing to climate change are complex -- a mix of chemicals such as carbon dioxide, water vapor, and methane, particles in the atmosphere that either reflect or absorb energy from the sun, and the interplay between plants, animals, humans, and the atmosphere. Most policymakers have been targeting carbon dioxide emissions as a key element of plans to try to reduce the effects of possible global warming. However, a recent study published in the Proceedings of the National Academy of Sciences suggests that if nations want to prevent global warming, they might do well to focus not only on carbon dioxide, but on other greenhouse gases as well.
The study, authored by James Hansen, an early researcher into global climate change, has stirred up yet more controversy in the often contentious global warming debate. We'll talk about it on this hour of Science Friday.
We'll also talk about observations made by several recent visitors to the Arctic of dramatically thinning sea ice -- even to the point of having liquid water at the pole itself. While some researchers are pointing to these observations as another point of support for global warming theories, others are saying that liquid water at the North Pole is not unusual and is not a cause for alarm. We'll find out more