The calamitous African drought on the flipside of the hurricane lull

Pollution has impacts, not all bad. Cleaning up pollution has impacts, not all good.

Last week, I wrote in Persuasion about the way European air pollution suppressed major hurricanes in the Atlantic from the 1960s to the 90s. That piece was for a Western audience, so naturally it showed what happened from a Western point of view. But all weekend I kept thinking that if people in Mali and Senegal spent a lot of money on Substack, I could have told the same story in a completely different way.

In the post-war period air pollution from Europe wafted south and cooled the Sahara. When it reached a critical threshold, in the 1960s, it began to interfere with the circulation pattern that gives rise to the West African monsoon — the heavy summer downpours that million of African farmers’ livelihoods depend on. The result was a calamitous, three-decade long drought over the Sahel — the band of semi-arid land between the verdant Gulf of Guinea coast and the desert. 

In normal times, the West African monsoon develops due to the temperature gradient between a very hot Sahara and a much cooler Gulf of Guinea. During the drought years, European pollution jammed up this mechanism by cooling the Sahara, giving rise to the drought that yielded a million “parched earth” photos like the one at the top of this post. 

Take a moment to mull the irony here: these images, so iconic for the climate movement, come from a drought set off not by global warming, but by aerosol cooling. 

But that’s not the end of the story, because the Sahel drought had its own set of second-order consequences: increasing the dust transport to the Caribbean, a process that ended up weakening hurricanes for much of the last third of the 20th century.

What strikes me is that standard climate journalism has left us unprepared to make sense of any of this. To begin to grasp how the Sahel drought came about, and how it could contribute to making hurricanes weaker in the 1960s, then stronger from the 90s, you have to be open to the idea that aerosols mediate the relationship between greenhouse gas emissions and the weather.

But that type of understanding is hard to come by in our public sphere, where climate stories must be framed around greenhouse effect alone. 

My sense is that much climate zealotry is a direct result of editing aerosols out of the story. Advocacy organizations haven’t found it convenient to communicate the impact of aerosols and journalists rarely report on it, so politicians and the public simply have never thought about it.  

The result is a disfigured climate conversation. Even the hurricane lull as such, the fact that there was a hurricane lull, has been edited out of the standard media narrative, so of course there’s no hope people will understand the European pollution dynamics and Sahelian droughts that seem to have given rise to it. Fail to grasp aerosol effects, and you just can’t make sense of an entire category of climate disruption that doesn’t have anything to do with the greenhouse effect.

The Sahel drought, for its part, was one of those tragedies we can’t exactly say we’ve forgotten simply because we never took much notice of it in the first place. Perhaps a hundred thousand people died due to famine and disease: a staggering toll we never think about because it took place in a region where, by convention, we aren’t required to give a shit about how many people live or die. 

But the famine wasn’t even the biggest legacy of the drought. Many millions more were forced to migrate, usually picking up sticks from fast desertifying land to go settle in the sprawl of miserable slums outside the region’s capitals: Bamako, Ouagadougou, places that grew from little more than villages to giant unmanageable cities at the center of disfunctional countries.

The Sahel has not done well. By the time the drought ended, it was playing host to an unholy melange of islamist insurgencies, Russian mercenaries and rapacious mining concerns. Its governments now face the constant threat of military coups and its territories are scarred with trafficking routes for illegal migrants headed to Europe. It’s easy to imagine these countries were always bound to be basketcases, but who knows where they might be today if unending drought hadn’t destroyed their rural economies. These are questions we simply never think about. 

Ironies abound here, though, because the hurricane lull coincided with a massive real estate boom all up-and-down the U.S. Eastern Seaboard, shoving untold billions of dollars into the pockets of real estate developers while also leaving the coast full of expensive real estate to be damaged when the big storms came back. Of course, the flipside is also true: the European clean air rules that brought back the big storms also gave rise to the re-greening of the Sahel.

People sometimes talk as though the governance problems facing any climate repair scheme were a never-before-seen conundrum. That’s only very partly true. Decisions made in one part of the world have had outsized effects on climate in entirely different regions for many for decades. Neither Sahelians nor Floridians got a say in the European clean air legislation that ended up ending the drought for the former, and setting off stronger hurricanes for the latter. Cleaning up Europe’s air involved an enormous tradeoff pitting the Sahel against North America and the Caribbean, it’s just that nobody realized it at the time.

And nobody wants to realize it now.

The climate movement sure as hell doesn’t want to face up to this, because it’s built a sort of theology around the unity of all good environmental things: a world where pollution is all bad and only bad, its results are only bad things, and where the solution to every ecological problem is the same: emit less. A morally comforting cosmos where right beliefs lead to right actions and right actions lead to right outcomes, a world where every calamity is retribution for our sins. 

The real world is much, much messier than that. In the real world, tradeoffs are inescapable.  Decisions that seem perfectly green can turn out to affect the climate through multiple pathways, some of which can have terrible unforeseen consequences. 

We live in a world where regreening Mali can mean exposing Haiti to stronger hurricanes. It’s a world of irreducible complexity, where the substances we put into the atmosphere have some effects we don’t want, other effects we do want, and where the real question isn’t whether we emit but what, where, in what concentrations, to whose benefit, and at whose expense. 

Once you write aerosols back into the climate story, you’re forced to go beyond easy sloganeering and to become the adult you want to see in the room.