Arctic lake yields climate record

DENVER — It took the better part of a decade, $10 million, and help from the guys who build ice roads for Canadian truckers. But scientists now have the most continuous record of ancient climate ever extracted from the terrestrial Arctic.

What’s more, the record — cored through sediment layers at the bottom of a lake in northeastern Siberia — also illuminates what happened when a big meteorite smashed into the spot 3.6