concerning Ice Ages

Carl Sagan’s Cosmos (the 1980 version) pulls off a neat trick in its first hour. In between a grand tour of the universe and the story of the Great Library of Alexandria, Sagan walks us through the experiment by which Erathosthenes calculated the diameter of the Earth. In about six minutes, Sagan has demonstrated to us that the ancients knew the Earth was round, AND that they knew how big it was, AND *HOW* they knew it was that size. The diameter of the Earth is not just some fact that came from a book, it was something they figured out, and you can too. It’s a trumph of presenting science as a process, rather than as a bunch of easily digestible factoids, which is what you normally see nowadays.

In an essay on Medium, Ben Thomas argues that “Sciencyness”, as he calls it, is harming science. “Scienceyness” is an analog of Stephen Colbert’s famous “truthiness”, which is to say it’s stuff that feels awfully scientific, even/especially if it’s not. Thomas goes on to point out a few cases where overblown hype has gone on to wreck projects, like the Human Brain project, or 1970s research into artificial intelligence. I personally wonder how many blanket “Doctors cure cancer!” headlines people are going to accept before they start to think that the doctors must have been lying to them before, and are probably lying to them now. (Fortunately, that’s one field of reporting that does seem to acknowledge the stages and imperfect nature of the results, even if they don’t always convey that there are multiple types and severities of cancers)

He’s hit onto something that’s been bothering me for some time. As a scientist, I read a lot of science news from a variety of sources both in and out of my field – If you take a look at the topics I’ve covered in previous posts, you’ll see a lot in there that’s outside the realm of stellar astronomy. Unfortunately, the more I’ve read, the more I find stories about astronomy that don’t really give any details about how the result was gathered, or even a sense that reasoning was necessary. Both good reliable results and offbeat cool-but-probably-wrong results are treated the same way.

What brings this up is the recent story that blasted around the web claiming there would be an ice age in 2030. To summarize, astronomers came out with a new, more accurate model of the magnetic field of the Sun that explains why the last solar maximum (when there are the most sunspots, it happens every ~11 years) was so weak and late, and they predicted conditions similar to the Maunder Minimum, during which basically no sunspots were recorded. That’s where the actual story in the press release ends. That’s also pretty much where the paper ends, too – it has more of a ‘check out our new snazzy computer model’ feel to it.

Then the press reports came in, and linked the Maunder minimum to the “Little Ice Age” observed in North America and Northern Europe around the same time. Various reports (which I can no longer find, probably because they have been corrected) also misreported the decrease in solar ACTIVITY as a decrease in solar irradiance, which WOULD have an enormous effect on climate… Clearly, we were going to freeze! WHERE IS YOUR GLOBAL WARMING NOW?

There are quite a few problems with this (in no apparent order):
1.) The Maunder Minimum had nothing to do with the Little Ice Age. It actually started earlier, and as this follow-up article points out, it probably had more to do with volcanism.
2.) The change in solar irradiance is minor. According to some sources, the Sun varies in cycles by 0.1-0.2%. X-ray flux coming from the magnetic fields drops significantly, but that’s actually only a tiny fraction of the total. Solar luminosity doesn’t seriously change unless you’re looking forward billions of years as the Sun slowly runs out of hydrogen to fuse.
3.) Any kind of ‘ice age’ would have to be pretty substantial to reverse global warming.

In summary, all of the headlines about this news were about mini ice ages, while the actual scientific study… wasn’t. What makes this particularly annoying is that astronomers and solar physicists have been pushing back against popular assumptions, congressional assumptions, and the occasional scientist like Willie Soon, that the Sun is the cause of global warming. It is not. That point has been tested and refuted, and and it gets tiring to have to see it up again and again.

So what should the media have done? The average person shouldn’t be expected to have all of that background about the Maunder minimum to have known immediately that something fishy was going on. Rather, it’s more like scientific reporting should accept that readers/viewers are going to think that whatever is reported is the latest absolute consensus on the issue, and try to frame the results with the appropriate amount of hesitation and context. And it’s up to us scientists and the science reporters to provide all that context. I’ve started this blog to try to, through practice, communicate my own work better. Many, many places and people do this well. Some, unfortunately, invent new ice ages.


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