Global Warming Predictions

Thirty years ago, a scientist named James Hansen testified before Congress about the dangers of global warming and his predictions for what global warming would look like.

Amusingly, both supporters and skeptics of global warming are claiming that the actual warming over the last thirty years supports their point of view. Or perhaps the word I'm looking for is "irritatingly". It's a little bit of both.

The skeptical article from the Wall Street Journal claims that what we've actually observed matches Hansen's third scenario the most closely - that was the scenario in which emissions stopped increasing in 2000. Of course, right after the note that "Global surface temperature has not increased significantly since 2000," comes the caveat: "...discounting the larger-than-usual El Niño of 2015-16."

I'll grant that whether the first half of that comment is true or not (I don't think it is, to be clear) does depend a bit on how one defines "significant" warming. Even without debating that point, though, discounting El Niño years doesn't seem like a great idea to me - or, at least, if you're going to do it, you should also take into account the effects like La Niña that might result in cooler temperatures. For example, you could compare trend lines for just the El Niño years, or just the La Niña years, or just the neutral years. If you do something like that - as seen in this article - you get a fairly clear picture of how temperatures are still getting warmer.