Daily Climate: A generation ago Jimmy Carter was in the White House, donning sweaters and telling Americans to turn down the thermostat. In the 35 years since, global emissions have almost doubled, from 18 billion metric tons of carbon dioxide a year in 1980 to almost 32 billion in 2011, the latest year available.
The impacts are increasingly being felt everywhere -- bigger storms in the Midwest, soggy summers in England, drought in Colorado. But nowhere on the planet are the impacts as dramatic as the Arctic,...