desi lydic has more. >> decembery: thank-- si: thank you, trevor, we're all going to die unless leadersan agree to massive across-the-board carbon cuts wisheddent be too hard. the debate over the severity of global climate change is decades old. some say time is running out. >> running out... a time of extraordinary urgency. >> it is happen hearing and now. others are really stupid. i ask the chair, you know what this is? it's a snowball, and that's just from outside here. so it's very, very cold out. >> desi: ridiculously, earth-shatteringly stupid. today, a large majority -- damn it! >> paris' summit is called earth's last shot. leaders in carbon emitters like the u.s., europe, china, russia, and all the less developed countries those have (bleep)ed over. the agreement to prevent nellie's apocalyptic vision. (singing) but how did we get in here? since 1880, human activity has warmed the earth's surface .85 degrees celsius with some already troubling effects. but more recently, humans have become far more efficient as making it hotter faster, without even looking back. in fact, in just