National Public Radio: European scientists were alarmed in 2008 when they discovered streams of methane bubbles erupting from the seafloor in Norway's high Arctic. This gas, which contributes to global warming, was apparently coming from methane ice on the seafloor. A follow-up study finds that methane bubble plumes at this location have probably been forming for a few thousand years, so they are not the result of human-induced climate change. But continued warming of ocean water can trigger more methane releases in the...