Watching talks like this is what helps me keep my sanity in the face of climate change and have hope we will do something about it. My take-away phrase of the speech is gonna be "do something". I know my doing something will not even register in the global scheme of things but I'm gonna do it anyway.
...the problem is, I'm not really convinced that we really know of a specific "something" that we can do that wouldn't backfire and make emissions even worse by creating perverse incentives elsewhere in the economy.
The only idea I've heard that would likely help in a meaningful way would be to simply make all domestic oil and natural gas extraction 100% illegal and try to convince some other nations to do the same. That one thing would raise world energy prices enough to curb consumption and would also slow down the economy enough to decrease emissions. (But the economic consequences of doing this would be brutal)