Climate Central: The worlds oceans could face a massive reshuffling by the end of the century the likes of which hasnt been seen in as many as 3 million years due to warming waters. Changes are already afoot in the oceans. Roughly 93 percent of the heat trapped by human greenhouse gas emissions is ending up in the worlds seas and already contributing to changes from slowing plankton growth to recent incursions of tuna near Alaska, thousands of miles from their normal range. If greenhouse gas emissions continue...