Good exploration, but I find it seriously flawed in one way. "Obama ruled the planet for almost a decade" is not at all true. The opposition party controlled the US Congress for nearly all that time. In the American system, the legislative branch (Congress) is the primary lawmaking authority, has constitutional authority over treaties (to ratify them or not), and controls funding for all government programs. One could argue just as easily that Obama was one of the least powerful (even lame duck) presidents due to his inability to pass much meaningful public policy. Given that political reality, the Paris agreement was quite a milestone achievement, certainly one that had eluded his Democratic predecessor. Obama's views on climate change and those of his party have been consistent for a long time now. I agree that it's possible to analyze this issue objectively, but in order to be objective, I think you need to take that context into account.