"President Trump's inexcusable abdication of America's crucial role in combating climate change is a calamitous mistake. Future generations may find our planet unlivable, and for what? Mindless adherence to an opportunistic campaign pledge? Top scientists implore us that this is our moment to avert disaster--and we won't get it back. Now it's up to the rest of us to fill the void--using every ounce of innovation, every chance at partnerships with cities, states, nations and private actors who understand all that's at stake--for us, and for those who will follow."