As CO2 concentrations near ominous benchmark, daily updates begin
Most people can mark their time on Earth by significant world events: the landing of a man on the moon, say; the dismantling of the Berlin Wall; or, more negatively, the 9/11 attacks. Another significant event is impending. Scientist Ralph Keeling wants this generation to remember when atmospheric concentrations of carbon dioxide reached 400 parts per million, because of humans.
Heavy rains and snow pose Midwest flood threats but begin to replenish Great Lakes
Scientists monitoring water levels in the Great Lakes said yesterday that the massive freshwater basin must reach equilibrium among evaporation, precipitation and runoff for the lakes to rebound to optimum levels for recreation, commerce and fisheries. But whether such equilibrium can be achieved, and for how long, remains an open question, said Drew Gronewold, a hydrologist at the National Oceanic and Atmospheric Administration's Great Lakes Environmental Research Laboratory in Ann Arbor, Mich.