The Good—And Bad—Of A Geoengineered Climate

IRA FLATOW: This is Science Friday. I’m Ira Flatow. A bit later in the hour, we’re going to get an update on those wildfires burning out west and talk about how a population boom could be fueling the flames.

But first, in this era of radical climate change, some scientists are thinking radically about how to cool the planet. I’m talking about geoengineering– intentionally manipulating the Earth’s atmosphere. It is a controversial idea and, as I say, with radical thinking, like using volcanoes. Here to tell us that story as well as other short subjects in science is Umair Irfan, staff writer for Vox covering climate and energy. Umair, welcome to Science Friday. Nice to have you back.

UMAIR IRFAN: Thank you for having me.

IRA FLATOW: Let’s talk about this geoengineering controversy. Why?

UMAIR IRFAN: Well, with geoengineering, there is a practical concern, and there’s a moral concern. The practical one is, basically, you’re messing with the planet’s climate. This is something that affects 7 and 1/2 billion people. Think about the controversy you may have in your office when it comes to setting the temperature there. Finding the equilibrium for the whole world is going to be a lot harder.

IRA FLATOW: And so how did the authors get around? Tell us what the idea is.

UMAIR IRFAN: Well the idea was that rather than deliberately manipulating the climate, they looked at experiments that were done for us in nature. And they realized that volcanoes seem like a very good proxy for what we could potentially do with the geoengineering. So a volcanic eruption– it sends millions of tons of soot, of ash, and, in particular, sulfur compounds into the atmosphere.

So they looked at two volcanic eruptions in particular. This was El Chichón in Mexico in 1982 and the Mount Pinatubo eruption in the Philippines in 1991. After both of these eruptions, the planet’s temperature as a whole declined by about a fraction of a degree centigrade. And they wanted to look at what happened to crops and agriculture in the wake of these eruptions to get a sense of what potential geoengineering would do in the future.

IRA FLATOW: And did it affect the crops?

UMAIR IRFAN: Yeah. They found that there were some crop declines due to lost sunlight. But there were also some rebounds due to lower temperatures. And they figure that looking forward into the future under a climate change scenario, the gains that we would get from lower temperatures that would help improve crops would be offset from the losses that we would get by reflecting more sunlight. In essence, it would be sort of a wash when you’re looking at temperature and sunlight.

IRA FLATOW: So geoengineering is still a tricky subject.

UMAIR IRFAN: Yeah, basically. Yeah. It shows that there’s some real trade-offs when we’re considering the impacts.

IRA FLATOW: Speaking of particles in the air, fires are still raging in California. And we’re going to talk more about that a little bit later. But you have a story about some weird weather they are bringing to the area.

UMAIR IRFAN: Yeah, that’s right. These fires in California are so massive that they can induce their own weather systems around them. And scientists reported just earlier this month that they saw pyrocumulus clouds.

These are clouds that are formed by the upward draft from the fires that emit soot and ash into the air and then also cause moisture to condense. They’re typically associated with volcanic eruptions. But seeing fires do this is kind of unusual. And these pyrocumulus clouds– they can behave like normal clouds in terms of producing rainfall and thunder and lightning.

Another thing that they saw was a fire whirl. This was in the car fire near Redding, California. And this was a massive spinning column of fire, smoke, and wind. Meteorologists don’t like the term “fire tornado,” but that’s kind of the effect that we’re looking at here. It generated winds of about 143 miles per hour. And meteorologists say that that might be the strongest spinning wind event in California’s history.

IRA FLATOW: Wow. Maybe a giant fire dust devil.

UMAIR IRFAN: Dust devil is a good analogy. But we’re talking about something that can uproot trees and spit throw cars.

IRA FLATOW: Up next, you have a story about gooey corn. I saw a picture of this on the internet. It really does look like corn covered in mucus. What’s going on here?

UMAIR IRFAN: Researchers are actually pretty excited about this. What you’re looking at is a picture of aerial roots of a maize, or corn, plant that was cultivated in the Sierra Mixe region of Oaxaca, Mexico. And this is the ancestral homeland of corn. This is where some of the most pristine and diverse strains of corn are.

And researchers realized that this plant was growing in very poor soil and at high altitudes. And yet, it was still producing food. And they were really curious as to why this was happening.

IRA FLATOW: And so is it extracting nitrogen out of the air? What’s causing the mucus on it?

UMAIR IRFAN: Well, the plant itself produces mucus, and it has sugar in it. And that allows it to cultivate bacteria. And that bacteria actually pulls nitrogen out of the air. So it’s a symbiotic relationship. Essentially, it’s fertilizing itself rather than trying to draw nutrients from the soil.

And this creates a really interesting possibility for crops around the world that currently depend on fertilizers. We spend upward of 5 million tons of fertilizer each year on corn crops. And corn is the largest grown crop here in the United States.

IRA FLATOW: Well, that seems terrific that it can take the nitrogen and fertilize itself out of the air. Why haven’t we known about this before– this kind of corn?

UMAIR IRFAN: Well, researchers observed this effect for decades. They saw this corn, but they couldn’t quite figure out what was the mechanism at work here. And only recently have we developed the modern genome sequencing tools and also the microbiome analysis tools to actually analyze the bacteria that were growing on this corn crop to see what they were actually doing and to verify that, in fact, they were pulling nitrogen out of the air and turning it into a form that could be usable for the plant itself.

IRA FLATOW: Is it possible to then grow this on a large scale for agricultural purposes, like we grow corn normally?

UMAIR IRFAN: That’s the idea. This is a maize crop. So technically, it probably could be crossbred with existing varieties of corn. And, as we mentioned, corn already uses a huge amount of fertilizer.

And if we could get it to produce some of its own, we could offset a huge amount of the environmental consequences associated with agriculture and fertilizer application– things like runoff that causes algae blooms and then dead zones and coastal waters. Those are things you can actually avoid by developing a crop that can feed itself.

IRA FLATOW: Finally, this is going to be a big weekend for space lovers. We’ve got the Parker Solar Probe scheduled to launch. And also, there’s the Perseid meteor shower, right?

UMAIR IRFAN: That’s right. That’s the one of the largest meteor showers of the year. It’s a spectacular space show. It’s caused by the wake of the Swift-Tuttle comet. And it’s a lot of small, pea-sized particles that are going to be passing through the atmosphere.

And already tonight and over the weekend, you’ll be able to see it. But Sunday night is when it peaks. And you will be able to see upwards of 60 meteors per hour. And this weekend, we also have a new moon. So the sky is going to be extra dark. So it’s definitely worth getting out there if you can.

IRA FLATOW: And unfortunately, it’s going to be extra cloudy where I live. I have missed all the planets. I’m going to miss the meteor shower.

UMAIR IRFAN: Might be worth the road trip.

IRA FLATOW: Yeah, road trip. You’ve got to get where it’s dark, get your eyes accumulated to seeing this.

UMAIR IRFAN: That’s right.

IRA FLATOW: This is a great meteor shower. It’s peaking this weekend, right?

UMAIR IRFAN: Yes, Sunday night.

IRA FLATOW: Sunday night. I hope you all can get out there. I hope to watch it online. Thank you, Umair.

UMAIR IRFAN: You bet.

IRA FLATOW: Umair Irfan is a reporter covering climate and energy for Vox.

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