Metal-Organic Frameworks

11 March, 2019

I’ve been talking about new technologies for fighting climate change, with an emphasis on negative carbon emissions. Now let’s begin looking at one technology in more detail. This will take a few articles. I want to start with the basics.

A metal-organic framework or MOF is a molecular structure built from metal atoms and organic compounds. There are many kinds. They can be 3-dimensional, like this one made by scientists at CSIRO in Australia:



And they can be full of microscopic holes, giving them an enormous surface area! For example, here’s a diagram of a MOF with yellow and orange balls showing the holes:



In fact, one gram of the stuff can have a surface area of more than 12,000 square meters!

Gas molecules like to sit inside these holes. So, perhaps surprisingly at first, you can pack a lot more gas in a cylinder containing a MOF than you can in an empty cylinder at the same pressure!

This lets us store gases using MOFs—like carbon dioxide, but also hydrogen, methane and others. And importantly, you can also get the gas molecules out of the MOF without enormous amounts of energy. Also, you can craft MOFs with different hole sizes and different chemical properties, so they attract some gases much more than others.

So, we can imagine various applications suited to fighting climate change! One is carbon capture and storage, where you want a substance that eagerly latches onto CO2 molecules, but can also easily be persuaded to let them go. But another is hydrogen or methane storage for the purpose of fuel. Methane releases less CO2 than gasoline does when it burns, per unit amount of energy—and hydrogen releases none at all. That’s why some advocate a hydrogen economy.

Could hydrogen-powered cars be better than battery-powered cars, someday? I don’t know. But never mind—such issues, though important, aren’t what I want to talk about now. I just want to quote something about methane storage in MOFs, to give you a sense of the state of the art.

• Mark Peplow, Metal-organic framework compound sets methane storage record, C&EN, 11 December 2017.

Cars powered by methane emit less CO2 than gasoline guzzlers, but they need expensive tanks and compressors to carry the gas at about 250 atm. Certain metal-organic framework (MOF) compounds—made from a lattice of metal-based nodes linked by organic struts—can store methane at lower pressures because the gas molecules pack tightly inside their pores.

So MOFs, in principle, could enable methane-powered cars to use cheaper, lighter, and safer tanks. But in practical tests, no material has met a U.S. Department of Energy (DOE) gas storage target of 263 cm3 of methane per cm3 of adsorbent at room temperature and 64 atm, enough to match the capacity of high-pressure tanks.

A team led by David Fairen-Jimenez at the University of Cambridge has now developed a synthesis method that endows a well-known MOF with a capacity of 259 cm3 of methane per cm3 under those conditions, at least 50% higher than its nearest rival. “It’s definitely a significant result,” says Jarad A. Mason at Harvard University, who works with MOFs and other materials for energy applications and was not involved in the research. “Capacity has been one of the biggest stumbling blocks.”

Only about two-thirds of the MOF’s methane was released when the pressure dropped to 6 atm, a minimum pressure needed to sustain a decent flow of gas from a tank. But this still provides the highest methane delivery capacity of any bulk adsorbent.

A couple things are worth noting here. First, the process of a molecule sticking to a surface is called adsorption, not to be confused with absorption. Second, notice that using MOFs they managed to compress methane by a factor of 259 at a pressure of just 64 atmospheres. If we tried the same trick without MOFs we would need a pressure of 259 atmospheres!

But MOFs are not only good at holding gases, they’re good at sucking them up, which is really the flip side of the same coin: gas molecules avidly seek to sit inside the little holes of your MOF. So people are also using MOFs to build highly sensitive detectors for specific kinds of gases:

Tunable porous MOF materials interface with electrodes to sound the alarm at the first sniff of hydrogen sulfide, Phys.Org, 7 March 2017.

And some MOFs work in water, too—so people are trying to use them as water filters, sort of a high-tech version of zeolites, the minerals that inspired people to invent MOFs in the first place. Zeolites have an impressive variety of crystal structures:





and so on… but MOFs seem to be more adjustable in their structure and chemical properties.

Looking more broadly at future applications, we can imagine MOFs will be important in a host of technologies where we want a substance with lots of microscopic holes that are eager to hold specific molecules. I have a feeling that the most powerful applications of MOFs will come when other technologies mature. For example: projecting forward to a time when we get really good nanotechnology, we can imagine MOFs as useful “storage lockers” for molecular robots.

But next time I’ll talk about what we can do now, or soon, to capture carbon dioxide with MOFs.

In the meantime: can you imagine some cool things we could do with MOFs? This may feed your imagination:

• Wikipedia, Metal-organic frameworks.




Breakthrough Institute on Climate Change

10 March, 2019

I found this article, apparently by Ted Nordhaus and Alex Trembath, to be quite thought-provoking. At times it sinks too deep into the moment’s politics for my taste, given that the issues it raises will probably be confronting us for the whole 21st century. But still, it raises big issues:

• Breakthrough Institute, Is climate change like diabetes or an asteroid?

The Breakthrough Insitute seeks “technological solutions to environmental challenges”, so that informs their opinions. Let me quote some bits and urge you to read the whole thing! Even if it annoys you, it should make you think a bit.

Is climate change more like an asteroid or diabetes? Last month, one of us argued at Slate that climate advocates should resist calls to declare a national climate emergency because climate change was more like “diabetes for the planet” than an asteroid. The diabetes metaphor was surprisingly controversial. Climate change can’t be managed or lived with, many argued in response; it is an existential threat to human societies that demands an immediate cure.

The objection is telling, both in the ways in which it misunderstands the nature of the problem and in the contradictions it reveals. Diabetes is not benign. It is not a “natural” phenomena and it can’t be cured. It is a condition that, if unmanaged, can kill you. And even for those who manage it well, life is different than before diabetes.

This seems to us to be a reasonably apt description of the climate problem. There is no going back to the world before climate change. Whatever success we have mitigating climate change, we almost certainly won’t return to pre-industrial atmospheric concentrations of greenhouse gases, at least not for many centuries. Even at one or 1.5 degrees Celsius of warming, the climate and the planet will look very different, and that will bring unavoidable consequences for human societies. We will live on a hotter planet and in a climate that will be more variable and less predictable.

How bad our planetary diabetes gets will depend on how much we continue to emit and how well adapted to a changing climate human societies become. With the present one degree of warming, it appears that human societies have adapted relatively well. Various claims attributing present day natural disasters to climate change are controversial. But the overall statistics suggest that deaths due to climate-related natural disasters globally are falling, not rising, and that economic losses associated with those disasters, adjusting for growing population and affluence, have been flat for many decades.

But at three or four degrees of warming, all bets are off. And it appears that unmanaged, that’s where present trends in emissions arelikely to take us. Moreover, even with radical action, stabilizing emissions at 1.5 degrees C, as many advocates now demand, is not possible without either solar geoengineering or sucking carbon emissions out of the atmosphere at massive scale. Practically, given legacy emissions and committed infrastructure, the long-standing international target of limiting temperature increase to two degrees C is also extremely unlikely.

Unavoidably, then, treating our climate change condition will require not simply emissions reductions but also significant adaptation to known and unknown climate risks that are already baked in to our future due to two centuries of fossil fuel consumption. It is in this sense that we have long argued that climate change must be understood as a chronic condition of global modernity, a problem that will be managed but not solved.

A discussion of the worst-case versus the best-case IPCC scenarios, and what leads to these scenarios:

The worst case climate scenarios, which are based on worst case emissions scenarios, are the source of most of the terrifying studies of potential future climate impacts. These are frequently described as “business as usual” — what happens if the economy keeps growing and the global population becomes wealthier and hence more consumptive. But that’s not how the IPCC, which generates those scenarios, actually gets to very high emissions futures. Rather, the worst case scenarios are those in which the world remains poor, populous, unequal, and low-tech. It is a future with lots of poor people who don’t have access to clean technology. By contrast, a future in which the world is resilient to a hotter climate is likely also one in which the world has been more successful at mitigating climate change as well. A wealthier world will be a higher-tech world, one with many more low carbon technological options and more resources to invest in both mitigation and adaptation. It will be less populous (fertility rates reliably fall as incomes rise), less unequal (because many fewer people will live in extreme poverty), and more urbanized (meaning many more people living in cities with hard infrastructure, air conditioning, and emergency services to protect them).

That will almost certainly be a world in which global average temperatures have exceeded two degrees above pre-industrial levels. The latest round of climate deadline-ism (12 years to prevent climate catastrophe according to The Guardian) won’t change that. But as even David Wallace Wells, whose book The Uninhabitable Earth has helped revitalize climate catastrophism, acknowledges, “Two degrees would be terrible but it’s better than three… And three degrees is much better than four.”

Given the current emissions trajectory, a future world that stabilized emissions below 2.5 or three degrees, an accomplishment that in itself will likely require very substantial and sustained efforts to reduce emissions, would also likely be one reasonably well adapted to live in that climate, as it would, of necessity, be one that was much wealthier, less unequal, and more advanced technologically than the world we live in today.

The most controversial part of the article concerns the “apocalyptic” or “millenarian” tendency among enviromentalists: the feeling that only a complete reorganization of society will save us—for example, going “back to nature”.

[…] while the nature of the climate problem is chronic and the political and policy responses are incremental, the culture and ideology of contemporary environmentalism is millenarian. In the millenarian mind, there are only two choices, catastrophe or completely reorganizing society. Americans will either see the writing on the wall and remake the world, or perish in fiery apocalypse.

This, ultimately, is why adaptation, nuclear energy, carbon capture, and solar geoengineering have no role in the environmental narrative of apocalypse and salvation, even as all but the last are almost certainly necessary for any successful response to climate change and will also end up in any major federal policy effort to address climate change. Because they are basically plug-and-play with the existing socio-technical paradigm. They don’t require that we end capitalism or consumerism or energy intensive lifestyles. Modern, industrial, techno-society goes on, just without the emissions. This is also why efforts by nuclear, carbon capture, and geoengineering advocates to marshall catastrophic framing to build support for those approaches have had limited effect.

The problem for the climate movement is that the technocratic requirements necessary to massively decarbonize the global economy conflict with the egalitarian catastrophism that the movement’s mobilization strategies demand. McKibben has privately acknowledged as much to several people, explaining that he hasn’t publicly recognized the need for nuclear energy because he believes doing so would “split this movement in half.”

Implicit in these sorts of political calculations is the assumption that once advocates have amassed sufficient political power, the necessary concessions to the practical exigencies of deeply reducing carbon emissions will then become possible. But the army you raise ultimately shapes the sorts of battles you are able to wage, and it is not clear that the army of egalitarian millenarians that the climate movement is mobilizing will be willing to sign on to the necessary compromises — politically, economically, and technologically — that would be necessary to actually address the problem.

Again: read the whole thing!


Negative Carbon Emissions

2 March, 2019

A carbon dioxide scrubber is any sort of gadget that removes carbon dioxide from the air. There are various ways such gadgets can work, and various things we can do with them. For example, they’re already being used to clean the air in submarines and human-occupied spacecraft. I want to talk about carbon dioxide scrubbers as a way to reduce carbon emissions from burning fossil fuels, and a specific technology for doing this. But I don’t want to talk about those things today.

Why not? It turns out that if you start talking about the specifics of one particular approach to fighting global warming, people instantly want to start talking about other approaches they consider better. This makes some sense: it’s a big problem and we need to compare different approaches. But it’s also a bit frustrating: we need to study different approaches individually so we can know enough to compare them, or make progress on any one approach.

I mainly want to study the nitty-gritty details of various individual approaches, starting with one approach to carbon scrubbing. But if I don’t say anything about the bigger picture, people will be unsatisfied.

So, right now I want to say a bit about carbon dioxide scrubbers.

The first thing to realize—and this applies to all approaches to battling global warming—is the huge scale of the task. In 2018 we put 37.1 gigatonnes of CO2 into the atmosphere by burning fossil fuels and making cement.

That’s a lot! Let’s compare some of the other biggest human industries, in terms of the sheer mass being processed.

Cement production is big. Global cement production in 2017 was about 4.1 gigatonnes, with China making more than the rest of the world combined, and a large uncertainty in how much they made. But digging up and burning carbon is even bigger. For example, over 7 gigatonnes of coal is being mined per year. I can’t find figures on total agricultural production, but in 2004 we created about 5 gigatonnes of agricultural waste. Total grain production was just 2.53 gigatonnes in 2017. Total plastic production in 2017 was a mere 348 megatonnes.

So, to use technology to remove as much CO2 from the air as we’re currently putting in would require an industry that processes more mass than any other today.

I conclude that this won’t happen anytime soon. Indeed David McKay calls all methods of removing CO2 from air “the last thing we should talk about”. For now, he argues, we should focus on cutting carbon emissions. And I believe that to do that on a large enough scale requires economic incentives, for example a carbon tax.

But to keep global warming below 2°C over pre-industrial levels, it’s becoming increasingly likely that we’ll need negative carbon emissions:


Indeed, a lot of scenarios contemplated by policymakers involve net negative carbon emissions. Often they don’t realize just how hard these are to achieve! In his talk Mitigation on methadone: how negative emissions lock in our high-carbon addiction, Kevin Anderson has persuasively argued that policymakers are fooling themselves into thinking we can keep burning carbon as we like now and achieve the necessary negative emissions later. He’s not against negative carbon emissions. He’s against using vague fantasies of negative carbon emissions to put off confronting reality!

It is not well understood by policy makers, or indeed many academics, that IAMs [integrated assessment models] assume such a massive deployment of negative emission technologies. Yet when it comes to the more stringent Paris obligations, studies suggest that it is not possible to reach 1.5°C with a 50% chance without significant negative emissions. Even for 2°C, very few scenarios have explored mitigation without negative emissions, and contrary to common perception, negative emissions are also prevalent in higher stabilisation targets (Figure 2). Given such a pervasive and pivotal role of negative emissions in mitigation scenarios, their almost complete absence from climate policy discussions is disturbing and needs to be addressed urgently.

Read his whole article!

Pondering the difficulty of large-scale negative carbon emissions, but also their potential importance, I’m led to imagine scenarios like this:

In the 21st century we slowly wean ourselves of our addiction to burning carbon. By the end, we’re suffering a lot from global warming. It’s a real mess. But suppose our technological civilization survives, and we manage to develop a cheap source of clean energy. And once we switch to this, we don’t simply revert to our old bad habit of growing until we exhaust the available resources! We’ve learned our lesson—the hard way. We start trying to cleaning up the mess we made. Among other things, we start removing carbon dioxide from the atmosphere. We then spend a century—or two, or three—doing this. Thanks to various tipping points in the Earths’ climate system, we never get things back to the way they were. But we do, finally, make the Earth a beautiful place again.

If we’re aiming for some happy ending like this, it may pay to explore various ways to achieve negative carbon emissions even if we can’t scale them up fast enough to stop a big mess in the 21st century.

(Of course, I’m not suggesting this strategy as an alternative to cutting carbon emissions, or doing all sorts of other good things. We need a multi-pronged strategy, including some prongs that will only pay off in the long run, and only if we’re lucky.)

If we’re exploring various methods to achieve negative carbon emissions, a key aspect is figuring out economically viable pathways to scale up those methods. They’ll start small and they’ll inevitably be expensive at first. The ones that get big will get cheaper—per tonne of CO2 removed—as they grow.

This has various implications. For example, suppose someone builds a machine that sucks CO2 from the air and uses it to make carbonated soft drinks and to make plants grow better in greenhouses. As I mentioned, Climeworks is actually doing this!

In one sense, this is utterly pointless for fighting climate change, because these markets only use 6 megatonnes of CO2 annually—less than 0.02% of how much CO2 we’re dumping into the atmosphere!

But on the other hand, if this method of CO2 scrubbing can be scaled up and become cheaper and cheaper, it’s useful to start exploring the technology now. It could be the first step along some economically viable pathway.

I especially like the idea of CO2 scrubbing for coal-fired power plants. Of course to cut carbon emissions it would be better to ban coal-fired power plants. But this will take a while:



So, we can imagine an intermediate regime where regulations or a carbon tax make people sequester the CO2 from coal-fired power plants. And if this happens, there could be a big market for carbon dioxide scrubbers—for a while, at least.

I hope we can agree on at least one thing: the big picture is complicated. Next time I’ll zoom in and start talking about a specific technology for CO2 scrubbing.


The Cost of Sucking

19 February, 2019

I’m talking about carbon dioxide scrubbers. This post will just be an extended quote from an excellent book, which is free online:

• David McKay, Sustainable Energy: Without the Hot Air.

It will help us begin to understand the economics. But some numbers may have changed since this was written! Also, the passage I’m quoting focuses on taking carbon dioxide out of the air. This not really what I’m researching now: I’m actually interested in removing carbon dioxide from the exhaust from coal-fired power plants, at least until we manage to eliminate these plants. But the two problems have enough similarities that it’s worth looking at the former.

Here is what McKay says:

The cost of sucking

Today, pumping carbon out of the ground is big bucks. In the future, perhaps pumping carbon into the ground is going to be big bucks. Assuming that inadequate action is taken now to halt global carbon pollution, perhaps a coalition of the willing will in a few decades pay to create a giant vacuum cleaner, and clean up everyone’s mess.

Before we go into details of how to capture carbon from thin air, let’s discuss the unavoidable energy cost of carbon capture. Whatever technologies we use, they have to respect the laws of physics, and unfortunately grabbing CO2 from thin air and concentrating it requires energy. The laws of physics say that the energy required must be at least 0.2 kWh per kg of CO2 (table 31.5). Given that real processes are typically 35% efficient at best, I’d be amazed if the energy cost of carbon capture is ever reduced below 0.55 kWh per kg.

Now, let’s assume that we wish to neutralize a typical European’s CO2 output of 11 tons per year, which is 30 kg per day per person. The energy required, assuming a cost of 0.55 kWh per kg of CO2, is 16.5 kWh per day per person. This is exactly the same as British electricity consumption. So powering the giant vacuum cleaner may require us to double our electricity production – or at least, to somehow obtain extra power equal to our current electricity production.

If the cost of running giant vacuum cleaners can be brought down, brilliant, let’s make them. But no amount of research and development can get round the laws of physics, which say that grabbing CO2 from thin air and concentrating it into liquid CO2 requires at least 0.2 kWh per kg of CO2.

Now, what’s the best way to suck CO2 from thin air? I’ll discuss four technologies for building the giant vacuum cleaner:

A. chemical pumps;
B. trees;
C. accelerated weathering of rocks;
D. ocean nourishment.

A. Chemical technologies for carbon capture

The chemical technologies typically deal with carbon dioxide in two steps.

  concentrate   compress  
0.03% CO2 Pure CO2 Liquid CO2

First, they concentrate CO2 from its low concentration in the atmosphere; then they compress it into a small volume ready for shoving somewhere (either down a hole in the ground or deep in the ocean). Each of these steps has an energy cost. The costs required by the laws of physics are shown in table 31.5.

In 2005, the best published methods for CO2 capture from thin air were quite inefficient: the energy cost was about 3.3 kWh per kg, with a financial cost of about $140 per ton of CO2. At this energy cost, capturing a European’s 30 kg per day would cost 100 kWh per day – almost the same as the European’s energy consumption of 125 kWh per day. Can better vacuum cleaners be designed?

Recently, Wallace Broecker, climate scientist, “perhaps the world’s foremost interpreter of the Earth’s operation as a biological, chemical, and physical system,” has been promoting an as yet unpublished technology developed by physicist Klaus Lackner for capturing CO2 from thin air. Broecker imagines that the world could carry on burning fossil fuels at much the same rate as it does now, and 60 million CO2-scrubbers (each the size of an up-ended shipping container) will vacuum up the CO2. What energy does Lackner’s process require? In June 2007 Lackner told me that his lab was achieving 1.3 kWh per kg, but since then they have developed a new process based on a resin that absorbs CO2 when dry and releases CO2 when moist. Lackner told me in June 2008 that, in a dry climate, the concentration cost has been reduced to about 0.18–0.37 kWh of low-grade heat per kg CO2. The compression cost is 0.11 kWh per kg. Thus Lackner’s total cost is 0.48 kWh or less per kg. For a European’s emissions of 30 kg CO2 per day, we are still talking about a cost of 14 kWh per day, of which 3.3 kWh per day would be electricity, and the rest heat.

Hurray for technical progress! But please don’t think that this is a small cost. We would require roughly a 20% increase in world energy production, just to run the vacuum cleaners.

Conclusion

Okay, this is me again: John Baez.

If you want to read about the other methods—trees, accelerated weathering of rocks, and ocean nourishment, go to McKay’s book. I’m not saying that they are less interesting! I am not trying, in this particular series of posts, to scan all technologies and find the best ones. I’m trying to study carbon dioxide scrubbers.


Climeworks

17 February, 2019

This article describes some recent work on ‘direct air capture’ of carbon dioxide—essentially, sucking it out of the air:

• Jon Gerntner, The tiny Swiss company that thinks it can help stop climate change, New York Times Magazine, 12 February 2019.

There’s a Swiss company called Climeworks that’s built machines that do this—shown in the picture above. So far they are using these machines for purposes other than reducing atmospheric CO2 concentrations: namely, making carbonated water for soft drinks, and getting greenhouses to have lots of carbon dioxide in the air, for tastier vegetables. And they’re just experimental, not economically viable yet:

The company is not turning a profit. To build and install the 18 units at Hinwil, hand-assembled in a second-floor workshop in Zurich, cost between $3 million and $4 million, which is the primary reason it costs the firm between $500 and $600 to remove a metric ton of CO₂ from the air. Even as the company has attracted about $50 million in private investments and grants, it faces the same daunting task that confronted Carl Bosch a century ago: How much can it bring costs down? And how fast can it scale up?

If they ever make it in these markets, greenhouses and carbonation might want 6 megatonnes of CO₂ annually. This is nothing compared to the 37 gigatonnes of CO₂ that we put into the atmosphere in 2018. In principle the technology Climeworks is using could be massively scaled up. After all, Napoleon used aluminum silverware, back when aluminum was more precious than gold… and only later did the technology for making aluminum improve to the point where the metal gained a mass market.

But can Climeworks’ technology actually be scaled up? Some are dubious:

M.I.T.’s Howard Herzog, for instance, an engineer who has spent years looking at the potential for these machines, told me that he thinks the costs will remain between $600 and $1,000 per metric ton. Some of Herzog’s reasons for skepticism are highly technical and relate to the physics of separating gases. Some are more easily grasped. He points out that because direct-air-capture machines have to move tremendous amounts of air through a filter or solution to glean a ton of CO₂ — the gas, for all its global impact, makes up only about 0.04 percent of our atmosphere — the process necessitates large expenditures for energy and big equipment. What he has likewise observed, in analyzing similar industries that separate gases, suggests that translating spreadsheet projections for capturing CO₂ into real-world applications will reveal hidden costs. “I think there has been a lot of hype about this, and it’s not going to revolutionize anything,” he told me, adding that he thinks other negative-emissions technologies will prove cheaper. “At best it’s going to be a bit player.”

What actually is the technology Climeworks is using? And what other technologies are available for sucking carbon dioxide out of the air—or out of the exhaust from fossil-fuel-burning power plants, or out of water?

I’ll have a lot more to say about the latter question in future articles. As for Climeworks, they describe their technology rather briefly here:

• Climeworks, Our technology.

They write:

Our plants capture atmospheric carbon with a filter. Air is drawn into the plant and the CO2 within the air is chemically bound to the filter.

Once the filter is saturated with CO2 it is heated (using mainly low-grade heat as an energy source) to around 100 °C (212 °F). The CO2 is then released from the filter and collected as concentrated CO2 gas to supply to customers or for negative emissions technologies.

CO2-free air is released back into the atmosphere. This continuous cycle is then ready to start again. The filter is reused many times and lasts for several thousand cycles.

What is the filter material?

The filter material is made of porous granulates modified with amines, which bind the CO2 in conjunction with the moisture in the air. This bond is dissolved at temperatures of 100 °C.

So, it seems their technology is an example of ‘amine gas treating’:

• Wikipedia, Amine gas treating.

In future posts I’ll talk a bit more about amine gas treating, but also other methods for absorbing carbon dioxide from air or from solution in water. Maybe you can help me figure out what’s the best method!


Exploring New Technologies

13 February, 2019

I’ve got some good news! I’ve been hired by Bryan Johnson to help evaluate and explain the potential of various technologies to address the problem of climate change.

Johnson is an entrepreneur who sold his company Braintree for $800M and started the OS Fund in 2014, seeding it with $100M to invest in the hard sciences so that we can move closer towards becoming proficient system administrators of our planet: engineering atoms, molecules, organisms and complex systems. The fund has invested in many companies working on synthetic biology, genetics, new materials, and so on. Here are some writeups he’s done on these companies.

As part of my research I’ll be blogging about some new technologies, asking questions and hoping experts can help me out. Stay tuned!




The Mathematics of the 21st Century

13 January, 2019

 

Check out the video of my talk, the first in the Applied Category Theory Seminar here at U. C. Riverside. It was nicely edited by Paola Fernandez and uploaded by Joe Moeller.

Abstract. The global warming crisis is part of a bigger transformation in which humanity realizes that the Earth is a finite system and that our population, energy usage, and the like cannot continue to grow exponentially. If civilization survives this transformation, it will affect mathematics—and be affected by it—just as dramatically as the agricultural revolution or industrial revolution. We should get ready!

The slides are rather hard to see in the video, but you can read them here while you watch the talk. Click on links in green for more information!