Undaunted courage: Alarmists weep over the alleged danger of trace amounts of invisible, harmless, natural atmospheric gas

Wal-Mart Senior VP Chokes Up Talking Sustainability (Video) : TreeHugger

But at 57:21, check out Kistler's closing remarks about why Wal-Mart will continue to pursue sustainability and climate-friendly policies: because the consumer will demand it, and companies like Wal-Mart may have no choice.

Why he teared up as he did isn't immediately clear -- perhaps the prospect of catastrophic climate change is truly upsetting to him. Or perhaps he was struck by the severe cynicality presented by Dr. Sanjayan of the Nature Conservancy, who spoke right before him and lamented that "nobody really cares about their grandchildren", arguing that may be part of the reason why we fail time and again to pass forward-thinking climate policy -- we're too selfish.

Either way, it was a supremely odd moment -- and a striking one, to say the least -- to see one of the most powerful marketing directors in the world (for the world's largest retailer, no less) break down over green issues.

Flashback: YouTube - John Doerr cries

At the end of the Kleiner Perkins partner's presentation at TED, about the perils of climate change, he chokes up.

Yvo de Boer steps down as UN climate chief to work for accountants KPMG | Environment | guardian.co.uk

De Boer became known as "the crying Dutchman" after he broke down in tears at the end of the Bali UN climate conference in 2006.