 Here on the west side of Rocky Mountain National Park, I'm in front of one of millions and millions of dead pine trees. They've been killed by pine bark beetles. Now pine bark beetles have always been here, but they're getting an extra generation per year, so there's more beetles in a year to attack the trees. And they're able to do this because it's warmer, the summers are getting longer, and that is partially due to climate change. In addition, snow melts early with warmer temperatures, and as a consequence, you get more drought stress during the summers, and when the trees are drought stressed, they have a harder time fighting off the beetles. Climate change didn't directly kill the trees. It didn't directly make the pine bark beetles, but it made them worse, and we're seeing treedure at death all over the west because climate change is making a normal problem a lot worse. We can just barely hear a helicopter down the hill. The helicopter has been looking at a fire which is burning in millions of trees like this. It was set by lightning. It's perfectly natural, but it's got all these dead trees to burn, and as a consequence the fire is much worse than usual, and rather than the Park Service being able to just let it burn, they're keeping very close watch on it to make sure it doesn't endanger things that people really care about and where people are. Climate change didn't cause the fire, but it made the fire worse. Down the hill, the lakes are really low now. There's drought stress, and the West has water problems no matter what. The West has always had droughts, but hotter summers make people want more water for their crops and their livestock. It makes water evaporate faster. That early snow melt from a warming world makes the streams low later in the summer, and so there's more water stress than there would have been. So climate change didn't make the pine bark beetles, but it's making them worse. It didn't make the fire, but it's making it worse. It didn't make the drought, but it's making it worse.