COPENHAGEN (Reuters) - China led calls by developing nations for deeper emissions cuts from the United States, Japan and Europe at U.N. climate talks on Tuesday, as a study showed that this decade will be the warmest on record. The first decade of this century was the hottest since records began, the World Meteorological Organisation said, underscoring the threat scientists say the planet faces from rising temperatures. Negotiators from nearly 200 countries are trying to seal the outlines of a climate pact to combat rising seas, desertification, floods and cyclones that could devastate economies and ruin the livelihoods of millions...