The hour on the climate clock has always been late. By the time NASA scientist James Hansen delivered his landmark Senate testimony in 1988, bringing “the greenhouse effect” to public attention for the first time, the atmospheric carbon count had surpassed 350 parts per million, considered the “safe” upper limit to avoid catastrophic climate change. Twenty years later, the count was sailing past 380 when Bill McKibben launched 350.org , a name chosen to bring attention to the urgent task of