How do you take the planet's temperature?

For this week’s show, we’re going to continue what we started last week: A brief interlude into the science of climate change. We’re right in the middle of what’s very likely to be the hottest year on record, and we’ve just passed what is historically the planet’s warmest week of the year. This week’s show will examine how we know what we know about our current climate. And to do that, we’ll rely on the reporting expertise of veteran environmental journalist, Andy Revkin.