In fact, I'm very proud of our government, because you can have a target and not have a plan, and then it doesn't really count for anything. We actually did the hard work that was required to come up with a plan, a very comprehensive plan, that was ambitious: phasing out coal by 2030, putting a price on carbon pollution, introducing a new low-carbon fuel standard, and historic investments in public transit and green infrastructure. But as part of the Paris agreement, as you know, you need to ratchet up your commitment, and we're certainly committed to doing that with the rest of the world.
On May 1st, 2017. See this statement in context.