More amateur climatology from Andrew Bolt
Andrew Bolt cites NASA data from the troposphere and stratosphere to show that global warming isn’t happening. He starts with the troposphere and makes what’s now a standard denialist talking point, that global temperatures “peaked in 1998” (a year of an exceptionally strong El Nino). Of course, until the last few years, denialists were (correctly for once) making the point that you couldn’t attribute all of the exceptional temperatures of 1998 to long-term climate change.
But Bolt’s new ace is the stratosphere, which is actually cooling. The graph here looks pretty convincing. Has Bolt discovered something that all the scientists have missed? Should he be publishing his findings in Nature. Well, no.
As NASA explains here, stratospheric cooling is also the result of human activity. The most important effect is from the destruction of the ozone layer, but CO2 emissions also play a role. Remember that the effect of greenhouse gases is to trap heat. This warms up the atmosphere below (in the troposphere), but reduces it above (in the stratosphere). There’s disagreement over the magnitude of this effect, but the direction is clear.
It would have taken Bolt five minutes with Google to find this out. Does he not know, or not care? Either way, he ought not to have a job with any responsible media organisation.
Note on comments: If you want to disagree with NASA, complain about the hockey stick, or otherwise dispute mainstream climate science, please follow the course I’ve suggested for Bolt and write to Nature. Or, if you really must attack science here, ask me nicely and I’ll put up an open thread. But for the purposes of this post, I’m going to take the assessment of the scientific evidence as presented by NASA and the IPCC as definitive. Comments disputing the science will be deleted.