10-07-23 Much organically bound carbon is deposited on inland lake bottoms. A portion remains in the sediment（沉淀） , sometimes for thousands of years, while the rest is largely broken down to carbon dioxide and methane（甲烷） , which are released into th...

10-06-04 Less ice covers the Arctic today than at any time in recent geologic（地质的） history. That's the conclusion of an international group of researchers, who have compiled the first comprehensive history of Arctic ice. For decades, scientists have str...