Connecting the Global Warming Dots

If thought of as a painting, the scientific picture of a growing and potentially calamitous human influence on the climate has moved from being abstract a century ago to impressionistic 30 years ago to pointillist today.

The impact of a buildup of carbon dioxide and other greenhouse gases is now largely undisputed. Almost everyone in the field says the consequences can essentially be reduced to a formula: More CO2 = warmer world = less ice = higher seas. (Throw in a lot of climate shifts and acidifying oceans for good measure.)

But the prognosis