Coming down to earth: What if a big geomagnetic storm does hit?

The fourth installment in my series on geomagnetic storms is now up on the GiveWell blog.

The first three posts were about the odds of a big storming hitting earth. This one shifts to the question of likely impacts. Mostly I think the evidence is reassuring. But given the stakes, I think we should not relax, and instead support more thorough research.

Geomagnetic storms: The “Big One” might only be twice as big as what’s already hit

The second post in my series on geomagnetic storms is up on It is arguably the most important and interesting in the series. It explains why I think past storms, reaching back to 1859, were probably at most twice as strong as anything our electricity-dependent societies have experienced in recent decades—and shrugged off.

Do you remember the great storms of 1982 and 2003? I didn’t notice them either. And probably you survived the Québec blackout of 1989, which was mostly over within 11 hours. Yet maybe that last doubling in storm intensity would inflict far, far more than twice as much destruction on the grid. Or maybe the grid has become much more vulnerable since 1989, even though grid operators have learned from that experience. It’s also possible I’m wrong that doubling is the worst we should fear. For all these reasons, I still think the threat deserves more attention from researchers, industry, and governments.

As I mentioned in my previous post, the strongest proponent for the view that the worst case is much worse, is John Kappenman, who has argued for a multiplier of 10 rather than 2. In the new post and the report, I trace this number in part to an obscure book of scientific scholarship written in 1925 by a Swedish telegraph engineer in French. The search involved talking to an electrical engineer in Finland, people at the Encyclopedia Britannica in Chicago (who were very helpful), and ordering said obscure book from a German book shop. Author David Stenquist describes how the storm of 1921 caused copper wires running into a telegraph office to melt—but not iron ones. He deduces that the storm-induced voltage on the line could not have been as high as 20 volts/kilometer. Yet through a scholarly game of telephone over the decades, this observation got turned on its head.

Below is a key section I scanned from the book’s yellowed pages. For more, read the post or the report.

Continue reading “Geomagnetic storms: The “Big One” might only be twice as big as what’s already hit”

Geomagnetic storms: Don’t panic

My long-promised report for the Open Philanthropy Project on geomagnetic storms is posted. (Data, code, and spreadsheets are here.) The first of a series of posts based on the report just appeared on the GiveWell blog.

This has been one of the most fun projects I’ve worked on because it slices across so many disciplines, from statistics to power engineering to astrophysics. My grasp of those subjects declines in the order listed…but I think I learned enough to reach a preliminary assessment.

The risk that a major solar cataclysm could so disrupt the earth’s magnetic field as to deprive continent-scale regions of power for years looks low to me—lower than the most attention-getting voices, almost by definition, have suggested (Pete RileyJohn Kappenman). Nevertheless, a long-term, large-area blackout would do so much harm, and the risk is so poorly studied, that it absolutely deserves more attention from researchers, industry, government, and philanthropies. My preliminary risk assessment could be wrong.

I just discovered that an elite, independent scientific advisory group for the US government arrived at a similar conclusion in 2011.

It follows that the most emphatic analysts, even if they have overshot, have done a service by drawing attention to the issue. This is for me a familiar paradox.

New package for extreme value analysis in Stata

One topic I’m studying for my main client, the Open Philanthropy Project, is the risk of geomagnetic storms. I hadn’t heard of them either. Actually, they originate as solar storms, which hurl magnetically charged matter toward earth, jostling its magnetic field. Routine-sized storms cause the Auroras Borealis and Australis. Big ones happen roughly once a decade (1972, 1982, 1989, 2003, a near-miss in 2012…) and also mostly hit high latitudes. The worry: a really big one could send currents surging through long-distance power lines, frying hundreds of major transformers, knocking out power to continent-scale regions for months or even years, and causing an economic or humanitarian catastrophe.

My best assessment at this point is that if one extrapolates properly from the available modern data, the risk is much lower than the 12%-chance-per-decade cited by the Washington Post last summer. But that’s a preliminary judgment, and I’m not a seasoned expert. And even if the risk is only 1%, it almost certainly deserves more attention. More from me on that in time. (For a mathematician’s doubts about the 12% figure see Stephen Parrott.)

You can see “geomagnetic storms” beneath Cari Tuna’s elbow in this photo from a recent Post story about the Open Philanthropy Project: Continue reading “New package for extreme value analysis in Stata”