What’s the difference between xkcd and Freakonomics?

The above, of course, is from xkcd. In contrast, Freakonomics went contrarian cool a bunch of years ago with “A Headline That Will Make Global-Warming Activists Apoplectic,” featuring a claim of “about 30 years of global cooling” and a preemptive slam at any critics for “shrillness.” I guess the Rogue Economists could issue a retraction …