This week, CEOs and world leaders met at the UN to talk climate. In the run-up to these high-level talks, many companies and some relatively new voices from the business community have been sounding both the alarm and the rallying cry for action. At the same time, the cost of renewable energy has dropped very far, very fast. It’s a perfect storm bringing us to two important tipping points: one of belief and commitment to action, and one of economics.