Since UN climate talks began in Mexico last week, there's been one issue that's threatened to seriously derail progress here at the summit – Japan's decision to back away from the Kyoto Protocol.
Why is this a big deal? The Kyoto Protocol is the world's only legally binding agreement for the reduction of greenhouse gases. Adopted in 1997, Kyoto obligates countries to take action to tackle climate change. And until more ambitious targets and policies are agreed internationally, Kyoto remains the only solution we've got.