Ice, ice, maybe: should the Arctic be refrozen?

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1:08Catherine Brahic:The Economist

1:15Rosie Blau:Hello and welcome to The Intelligence from The Economist. I'm Rosie Bloor.

1:20Catherine Brahic:And I'm Jason Palmer. Every weekday, we provide a fresh perspective on the events shaping your world.

1:29Rosie Blau:These days in India, you can order street snacks, household appliances, or a single bar of soap to arrive at your door within minutes. But what of the delivery drivers racing through the crazy traffic to meet those whims? Our correspondent reports.

1:45Catherine Brahic:And we've talked a lot recently about independent AI agents. And we've talked a lot about the weird and troubling things that arise on social networks. Now, what happens when a bunch of AI agents are cut loose on their very own social network?

2:06Rosie Blau:First up, though.

2:16Rosie Blau:As more and more of the Arctic disappears, the debate around it is getting louder.

2:22Catherine Brahic:Climate change is transforming the Arctic faster than any other place. If you take a look outside of Greenland right now, there are Russian destroyers. Making clear our commitment to ensuring Arctic security.

2:34Rosie Blau:For some leaders, the problem is less environmental than geopolitical. Donald Trump worries that the Great Thaw is a threat to America's security, allowing Russia and China access to new routes, new resources and new influence. Yet America's president has shown little interest in stopping the melting in the first place. The US officially left the Paris Agreement again in January. Last week, Trump repealed a key ruling that greenhouse gases harm public health, a judgment that has underpinned all federal actions to curb them since 2009.

3:07Catherine Brahic:We are officially terminating the so-called endangerment finding.

3:12Rosie Blau:So as the ice continues to retreat, some more radical ideas are gaining momentum. What if we could refreeze the Arctic? And to discuss these radical ideas, I'm joined by Katrine Braik, our environment editor, and Oliver Morton, one of our senior editors at The Economist. Hello both. pleasure to be here. Olly, there's so much discussion about what to do about the Arctic, but you've been writing about two rather extreme sounding proposals. Tell me about those.

3:45Kira Huju:Sure. I mean, there's a background of people who've been talking about various ways of intervening in Arctic landscapes. The University of the Arctic has a list of 61 of them. The two that I was writing about the other week were forms of what's called solar geoengineering, which is ways of making more sunlight bounce off the Earth, out of its atmosphere before it gets to warm the surface. One is called marine cloud brightening and the other one is called stratospheric aerosol injection. They're done in rather different ways. They have somewhat similar effects. There's recently been more research into both of them.

4:21Rosie Blau:Okay, so let's start with marine brightening. It's a good name. What does it involve?

4:26Kira Huju:Marine brightening goes back to a guy called John Latham in the 1990s, who noticed that we know that little bits of salt or little particles in the lower atmosphere over some parts of the sea brighten and extend the length of life of clouds. And so if you brighten clouds and make them longer lived, you will reflect away more sunlight. And you get some of the same effect if you put these little particles in and you don't even form a cloud. And there's some fairly good evidence of that from looking at low-lying volcanic eruptions in Iceland, which has just sent low levels of particles out in the lower atmosphere.

5:02Kira Huju:Recently, there were some studies led by Matthew Henry at the University of Exeter looking at what marine cloud brightening would do if you could do it over all of the Arctic Ocean that wasn't frozen pretty much all of the time. And the results were moderately encouraging in that they showed you that you got less sea ice loss, maybe even some sea ice recovery.

5:23Rosie Blau:And what about the second idea that you've been looking at, stratospheric aerosol injection?

5:29Kira Huju:So stratospheric aerosol injection is a way of brightening the upper atmosphere by putting a thin layer of hazy particles up in the stratosphere. And these would be particles very like the sulphate particles, which are air pollution in the lower atmosphere. But because they'd be in the upper atmosphere, they would last much longer and they would provide thus much more cooling per kilo of sulphur. than sulfur in the lower atmosphere does. And the reason why this is of particular interest in the Arctic and indeed the Antarctic is that in the tropics and the middle altitudes, the bottom of the stratosphere is a long way above where airplanes go.

6:10Kira Huju:Near the poles, the bottom of the stratosphere is much closer. So that means that if you wanted to put sulfur into the stratosphere, you could in fact do so over the poles. And I should make a point here, which is that I have a role as a trustee in an NGO that encourages research into stratospheric aerosol injection in the global south. Not with the idea of creating an impulse for that, but on the basis that the global south must be informed on this subject.

6:40Rosie Blau:And why are we thinking about such extreme ideas? What are the benefits?

6:45Jason Palmer:The pros of refreezing the Arctic are primarily you're cooling the part of the world that is currently warming the fastest. And that matters, even though you don't have that many people. But secondly, it actually matters to the rest of the globe as well. So the difference in temperature between the Arctic and the lower latitudes has all kinds of regulatory impacts on weather patterns across the rest of the planet. So you want this ice cap there for that reason. It's also a really important driver of what we know as the ocean conveyor belt. It's basically the currents that move water all around the global oceans.

7:25Jason Palmer:One other really important one that I should mention is that as the Arctic is thawing, you're thawing the permafrost and the permafrost is a huge store of methane. So if you lose that ice cap, you risk releasing all of this methane up into the atmosphere and that creates a positive feedback loop, accelerating the rate of global warming.

7:44Rosie Blau:It's all still sounding quite bonkers to me and sounds quite dangerous. Surely there are problems with these ideas.

7:52Jason Palmer:You're right. There are unknowns and so they sound bonkers. There are also some important risks which need to be discussed. So none of these methods address ocean acidification. If you're talking about stratospheric aerosol injections, for instance, Often, generally, what you're talking about there at the minute is injecting sulfates into the atmosphere. That can do things like eat away at the ozone hole. It all depends really on how you structure these sunshades. And I think one key hesitation, one key source of controversy is that it's not very well researched. There's lots of different ways that you could deploy this.

8:30Jason Palmer:And so one really strong call that is out there and that I think both Oli and I would support is that we need to understand these proposals in much, much greater detail than has been done so far.

8:43Rosie Blau:Are these ideas actually feasible? And if they are, who would do it? I mean, we haven't seen much in the way of international unity on really anything recently.

8:55Jason Palmer:Some of these methods are surprisingly simple, and that creates the problem of who would do it. You immediately go into governance questions of do they have the right? Can they do that? How does the rest of the world feel about that? I think these are just questions that need to be studied and understood. it.

9:15Kira Huju:There is a huge problem, as Kat points to, in that because it's relatively easy to do this, especially after someone has started doing it, you have what some scholars in the field call the free driver problem. The free driver problem is that you can always increase the amount of solar geoengineering fairly easily, and you can't reduce it unilaterally at all. And so you will end up with probably the level of solar geoengineering in such a scenario which suited the power which wanted the most solar geoengineering and that's a real worry.

9:48Jason Palmer:And where would it end? So this is the key question and an important thing to understand here is that if you're injecting particles into the stratosphere they rain out of the stratosphere so you need to keep resupplying your sunshade. And what that means is that you're committing to resupply a sunshade until such a time as you decide that the world can cope with the consequences. Now, the consequences are that in the background, greenhouse gas emissions are still accumulating in the atmosphere. So if you suddenly remove the sunshade for whatever reason or forget to resupply it, then over the course of a decade or maybe two, you're suddenly hit with a full force of the warming from those accumulated greenhouse gas emissions.

10:33Jason Palmer:It's the warming that you've been masking. That is a really scary scenario. The only way of countering that is to remove CO2 emissions from the atmosphere, carbon capture and storage, direct air capture. Again, there are solutions out there, but they're nowhere near ready at the kinds of scales that we need. So unless we have that, the solution for sucking CO2 out of the atmosphere, then I think you have a real problem with where the stratospheric aerosol injection ends.

11:02Kira Huju:I think that's true. And I think we have to acknowledge that were solar geoengineering to be deployed sometime in the next decade, it would be without knowing how it ends. And that's not to be flippant about it. You cannot say what people in generations to come will do with this knowledge or do with this technology. the answer I think is to try and research so you can make rational decisions now about what is in the interest of a group that you represent to do in this area and if you think that it's unsatisfactory I would be the first person to agree with you.

11:40Rosie Blau:Kat, Olly, thank you very much.

11:42Kira Huju:Thanks very much.

11:43Rosie Blau:Thank you both.

11:51Thank you.

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13:05Oliver Morton:Things in India take their sweet time. From bureaucracy to traffic, the country's not exactly known for its punctuality. Kira Huyu is our Asia correspondent. But you want party snacks? You want the new iPhone? A single bar of soap? These can appear on your doorstep in a matter of minutes, thanks to India's gig economy boom. In fact, just this morning, I got one of India's biggest delivery apps to print out my visa application for me and deliver it to my flat in exactly 11 minutes. across europe and america these kinds of quick commerce apps have actually been floundering so what's the secret behind india's gig economy boom it is a virtually unlimited pool of cheap labor local delivery apps like blink it big basket and zepto rely on a hard-pressed army of local gig workers the food delivery app swiggy claims that on new year's eve 2025 its drivers collectively travelled eight times the distance from Earth to the moon and back again.

14:20Rosie Blau:So Kira, put some numbers on this army of gig workers. How many are there?