Reuters: Old forests from Alaska to Russia soak up vast amount of greenhouse gases as they age and are wrongly overlooked as a weapon in a UN-led fight against global warming, a study said on Wednesday. “New growth continues in forests that are centuries old,” an international team of scientists wrote in the journal Nature of old forests outside the tropics that make up 15 percent of the world’s total tree-covered area. Plants soak up heat-trapping carbon from the air as they grow and …