 It's a cold day in Pennsylvania in a cold winter in a warming world. Some days this winter most of Alaska has been hotter than Pennsylvania. Some days the North Pole was hotter and my colleagues working in Antarctica had warmer temperatures than we had here. The global warming is only about a degree so far and that's small enough that we do have record lows but it's enough to validate our scientific understanding which shows with high confidence that if we keep burning fossil fuels and releasing CO2 we face much larger climate changes than what has happened so far. A little warming winners and losers. A lot of warming more and more losers it gets harder and harder. The snow we knew it was coming because we had a good weather forecast. We know when hurricanes or typhoons or tornadoes when floods and heat waves and cold snaps are coming because weather forecasts are good. They're not perfect but they give us information we can use. Weather is one roll of the dice. Climate is the average of a bunch of roles but otherwise they're often done by the same companies, the same government agencies, people in the same departments and universities, people trained in the same ways using similar the same tools and climate projections are skillful too. They don't tell you what to do but they do tell you what you can do and we have very high confidence that if we use the climate projections together with what we care about and where we want to go that we can make a brighter future. If we release the CO2 from all our fossil fuels to the air, burn before we learn, we face a terrible energy crisis in a world that's much harder to live in. If we use the scholarship, the knowledge of sustainable alternatives, we face a world that can affordably power everyone almost forever. Since our ancestors first started burning trees faster than they grew back, we have not been able to make a sustainable energy system and now we can. Speaking for the instructional team, we hope you've learned a lot from this course. We hope you've enjoyed what you learned and it is useful to you and we hope that you see the remarkably bright future that awaits all of us. Thanks for coming.