Critical metals and the side effects of electrification

A review of Power Metal: The Race for the Resources That Will Shape The Future

Also published on Resilience.

“The energy transition from fossil fuels to renewables is a crucial part of the cure for climate change,” writes Vince Beiser on page one of his superb new book Power Metal. “But it’s a cure with brutal side effects.”

The point of Beiser’s stark warning is not to downplay the urgency of switching off fossil fuels, nor to assert that a renewable energy economy will be a greater ecological menace than our current industrial system.

Power Metal by Vince Beiser, published November 2024 by Riverhead Books.

But enthusiasm for supposedly clean and free solar and wind energy must be tempered by a realistic knowledge of the mining and refining needed to produce huge quantities of solar panels, wind turbines, transmission lines, electric motors, and batteries.

In Power Metal, Beiser explains why we would need drastic increases in mining of critical metals – including copper, nickel, cobalt, lithium, and the so-called “rare earths” – if we were to run anything like the current global economy solely on renewable electricity.

Beyond merely outlining the quantities of metals needed, however, he provides vivid glimpses of the mines and refineries where these essential materials are extracted and transformed into usable commodities. His journalistic treatment helps us understand the ecological impacts of these industries as well as the social and health impacts on the communities where this work is done, often in horrible conditions.

While cell phones and computers in all their billions each contain small quantities of many of the critical metals, the much-touted electric vehicle transition has a deeper hunger. Take nickel. “Stainless steel consumes the lion’s share of nickel output,” Beiser writes, “but batteries are gaining fast.” (page 69)

“The battery in a typical Tesla,” he adds, “is as much as 80 percent nickel by weight. The battery industry’s consumption of nickel jumped 73 percent in 2021 alone.” (p 69)

And so on, down the list: “a typical EV contains as much as one hundred seventy-five pounds of copper.” ( p 45)

“Your smartphone probably contains about a quarter ounce of cobalt; electric vehicle batteries can contain upwards of twenty-four pounds.” (p 77)

Extending current trend lines leads to the following prediction:

“By 2050, the International Energy Agency estimates, demand for cobalt from electric vehicle makers alone will surge to nearly five times what it was in 2022; nickel demand will be ten times higher; and for lithium, fifteen times higher ….” (p 4)

If those trend lines hold true – and that’s a big “if” – the energy transition will come with high ecological costs.

The historic leading producer of nickel, Norilsk in Siberia, “is one of the most ecologically ravaged places on Earth.” (p 70) Unfortunately a recent contender in Indonesia, where the nickel ore is a lower quality, may be even worse:

“Nickel processing also devours huge amounts of energy, and most of Indonesia’s electricity is generated by coal-fired plants. That’s right: huge amounts of carbon-intensive coal are being burned to make carbon-neutral batteries.” (p 74)

The Bayan Obo district in China is the world’s major producer of refined rare earths – and “not by coincidence, it is also one of the most polluted areas on the planet. …” (p 28)

Ideally we’d want the renewable energy supply chain to meet three criteria: cheap, clean, and fair. As it is, we’re lucky to get one out of three.

Mining of critical metals can only take place in particular locations – blessed or cursed? – where such elements are somewhat concentrated in the earth’s crust. When there is a choice of nations for suppliers, the global economy leans to nations with lax environmental and labour standards as well as low wages.

There are no geographic restrictions on processing, however, and that’s why China’s dominance in critical metal processing far exceeds its share of world reserves.

The Mountain Pass mine in California is rapidly expanding extraction of rare earths. But the US facility is only able to produce a commodity called bastnaesite, which contains all the rare earths mixed together. To separate the rare earth elements one from another, the mine operator tells Beiser, the bastnaesite must be shipped to China: “ There’s no processing facilities anywhere outside of China that can handle the scale we need to be producing.” (p 36)

The story is similar for other critical metals. Cobalt, for example, is mined in famously brutal conditions in the Democratic Republic of Congo, and then sent to China for processing.

Could both the mining and the processing be done in ways that respect the environment and respect the health and dignity of workers? Major improvements in these respects are no doubt possible – but will likely result in a significantly higher price for renewable energy technologies. Our ability to pay that price, in turn, will be greatly influenced by how parsimoniously or how profligately we use the resulting energy. 

Collection of circuit boards at Agbogbloshie e-waste processing plant in Ghana. Image from Fairphone under Creative Commons license accessed via flickr.

Recycling to the rescue?

Is the messy extraction and processing of critical metals just a brief blip on a rosy horizon? Proponents of recycling sometimes make the case that the raw materials for a renewable energy economy will only need to be mined once, after which recycling will take over.

Beiser presents a less optimistic view. A complex global supply chain manufactures cars and computers that are composites of many materials, and these products are then distributed to every corner of the world. Separating out and re-concentrating the various commodities so they can be recycled also requires a complex supply chain – running in reverse.

“Most businesses that call themselves metal recyclers don’t actually turn old junk into new metal,” Beiser writes. “They are primarily collectors, aggregators.” (p 130) He takes us into typical work days of metal collectors and aggregators in his hometown of Vancouver as well as in Lagos, Nigeria. In these and other locations, he says, the first levels of aggregation tend to be done by people working in the informal economy.

In Lagos, workers smash apart cell phones and computers, and manually sort the circuit boards into categories, before the bundles of parts are shipped off to China or Europe for the next stage of reverse manufacturing:

“Shredding or melting down a circuit board and separating out those tiny amounts of gold, copper, and everything else requires sophisticated and expensive equipment. There is not a single facility anywhere in Africa capable of performing this feat.” (p 145)

Because wages are low and environmental regulations lax in Nigeria and Ghana, it is economically possible to collect and aggregate almost all the e-waste components there. Meanwhile in the US and Europe, “fewer than one in six dead mobile phones is recycled.” (p 146)

Cell phones are both tiny and complicated, but what about bigger items like solar panels, wind turbine blades, and EV batteries?

Here too the complications are daunting. It is currently far cheaper in the US to send an old solar panel to landfill than it is to recycle it. There isn’t yet a cost-effective way to separate the composite materials in wind turbine blades for re-use.

Lithium batteries add explosive danger to the complications of recycling: 

“If they’re punctured, crushed, or overheated, lithium batteries can short-circuit and catch on fire or even explode. Battery fires can reach temperatures topping 1,000 degrees Fahrenheit [538°C], and they emit toxic gases. Worse, they can’t be extinguished by water or normal firefighting chemicals. (p 153)

Perhaps it’s not surprising that only 5% of lithium-ion batteries are currently recycled. (p 151)

Given the costs, dangers, and complex supply chain needed, Beiser says, recycling is not “the best alternative to using virgin materials. In fact, it’s one of the worst.” (p 16)

Far better, he argues in the book’s closing section, are two other “Rs” – “reuse” and “reduce.”

Simply using all the cell phones in Europe for one extra year before junking them, he says, would avoid 2.1 million metric tons of carbon dioxide emissions per year –comparable to taking a million cars off the road.

Speaking of taking cars off the road, Beiser writes, “the real issue isn’t how to get more metals into the global supply chain to build more cars, it’s how to get people to where they want to go with fewer cars.” (p 186)

Given the high demands for critical metals involved in auto manufacturing, Beiser concludes that “the most effective single way that we as individuals can make a difference is this: Don’t buy a car. Not even an electric one.” (p 182) He might have added: if you do buy a car, get one that’s no bigger or heavier than needed for your typical usage, instead of the ever bulkier cars the big automakers push.

In response to projections about how fast we would need to convert the current world economy to renewable energy, Beiser fears that it may not be possible to mine critical metals rapidly enough to stave off cataclysmic climate change. If we dramatically reduce our demands for energy from all sources, however, that challenge is not as daunting:

“The less we consume, the less energy we need. The less energy we use, the less metal we need to dig up …. Our future depends. in a literal sense, on metal. We need a lot of it to stave off climate change, the most dangerous threat of all. But the less of it we use, the better off we’ll all be.” (p 204-205)

  • * *

“Energy transition” is a key phrase in Power Metal – but does this transition actually exist? Andreas Malm and Wim Carton make the important point that both “energy transition” and “stranded assets” remain mere future possibilities, each either a fond dream or a nightmare depending on one’s position within capitalist society. All the renewable energy installations to date have simply been additions to fossil energy, Malm and Carton point out, because fossil fuel use, a brief drop during the pandemic aside, has only continued to rise.

We turn to Malm and Carton’s thought-provoking new book Overshoot in our next installment.

Image at top of page: “Metal worker at Hussey Copper in Leetsdale, PA melts down copper on August 8, 2015,” photo by Erikabarker, accessed on Wikimedia Commons.

A road map that misses some turns

A review of No Miracles Needed

Also published on Resilience

Mark Jacobson’s new book, greeted with hosannas by some leading environmentalists, is full of good ideas – but the whole is less than the sum of its parts.

No Miracles Needed, by Mark Z. Jacobson, published by Cambridge University Press, Feb 2023. 437 pages.

The book is No Miracles Needed: How Today’s Technology Can Save Our Climate and Clean Our Air (Cambridge University Press, Feb 2023).

Jacobson’s argument is both simple and sweeping: We can transition our entire global economy to renewable energy sources, using existing technologies, fast enough to reduce annual carbon dioxide emissions at least 80% by 2030, and 100% by 2050. Furthermore, we can do all this while avoiding any major economic disruption such as a drop in annual GDP growth, a rise in unemployment, or any drop in creature comforts. But wait – there’s more! In so doing, we will also completely eliminate pollution.

Just don’t tell Jacobson that this future sounds miraculous.

The energy transition technologies we need – based on Wind, Water and Solar power, abbreviated to WWS – are already commercially available, Jacobson insists. He contrasts the technologies he favors with “miracle technologies” such as geoengineering, Carbon Capture Storage and Utilization (CCUS), or Direct Air Capture of carbon dioxide (DAC). These latter technologies, he argues, are unneeded, unproven, expensive, and will take far too long to implement at scale; we shouldn’t waste our time on such schemes.  

The final chapter helps to understand both the hits and misses of the previous chapters. In “My Journey”, a teenage Jacobson visits the smog-cloaked cities of southern California and quickly becomes aware of the damaging health effects of air pollution:

“I decided then and there, that when I grew up, I wanted to understand and try to solve this avoidable air pollution problem, which affects so many people. I knew what I wanted to do for my career.” (No Miracles Needed, page 342)

His early academic work focused on the damages of air pollution to human health. Over time, he realized that the problem of global warming emissions was closely related. The increasingly sophisticated computer models he developed were designed to elucidate the interplay between greenhouse gas emissions, and the particulate emissions from combustion that cause so much sickness and death.

These modeling efforts won increasing recognition and attracted a range of expert collaborators. Over the past 20 years, Jacobson’s work moved beyond academia into political advocacy. “My Journey” describes the growth of an organization capable of developing detailed energy transition plans for presentation to US governors, senators, and CEOs of major tech companies. Eventually that led to Jacobson’s publication of transition road maps for states, countries, and the globe – road maps that have been widely praised and widely criticized.

In my reading, Jacobson’s personal journey casts light on key features of No Miracles Needed in two ways. First, there is a singular focus on air pollution, to the omission or dismissal of other types of pollution. Second, it’s not likely Jacobson would have received repeat audiences with leading politicians and business people if he challenged the mainstream orthodox view that GDP can and must continue to grow.

Jacobson’s road map, then, is based on the assumption that all consumer products and services will continue to be produced in steadily growing quantities – but they’ll all be WWS based.

Does he prove that a rapid transition is a realistic scenario? Not in this book.

Hits and misses

Jacobson gives us brief but marvelously lucid descriptions of many WWS generating technologies, plus storage technologies that will smooth the intermittent supply of wind- and sun-based energy. He also goes into considerable detail about the chemistry of solar panels, the physics of electricity generation, and the amount of energy loss associated with each type of storage and transmission.

These sections are aimed at a lay readership and they succeed admirably. There is more background detail, however, than is needed to explain the book’s central thesis.

The transition road map, on the other hand, is not explained in much detail. There are many references to scientific papers in which he outlines his road maps. A reader of No Miracles Needed can take Jacobson’s word that the model is a suitable representation, or you can find and read Jacobson’s articles in academic journals – but you don’t get the needed details in this book.

Jacobson explains why, at the level of a device such as a car or a heat pump, electric energy is far more efficient in producing motion or heat than is an internal combustion engine or a gas furnace. Less convincingly, he argues that electric technologies are far more energy-efficient than combustion for the production of industrial heat – while nevertheless conceding that some WWS technologies needed for industrial heat are, at best, in prototype stages.

Yet Jacobson expresses serene confidence that hard-to-electrify technologies, including some industrial processes and long-haul aviation, will be successfully transitioning to WWS processes – perhaps including green hydrogen fuel cells, but not hydrogen combustion – by 2035.

The confidence in complex global projections is often jarring. For example, Jacobson tells us repeatedly that the fully WWS energy system of 2050 “reduces end-use energy requirements by 56.4 percent” (page 271, 275).1 The expressed precision notwithstanding, nobody yet knows the precise mix of storage types, generation types, and transmission types, which have various degrees of energy efficiency, that will constitute a future WWS global system. What we should take from Jacobson’s statements is that, based on the subset of factors and assumptions – from an almost infinitely complex global energy ecosystem – which Jacobson has included in his model, the calculated outcome is a 56% end-use energy reduction.

Canada’s Premiers visit Muskrat Falls dam construction site, 2015. Photo courtesy of Government of Newfoundland and Labrador; CC BY-NC-ND 2.0 license, via Flickr.

Also jarring is the almost total disregard of any type of pollution other than that which comes from fossil fuel combustion. Jacobson does briefly mention the particles that grind off the tires of all vehicles, including typically heavier EVs. But rather than concede that these particles are toxic and can harm human and ecosystem health, he merely notes that the relatively large particles “do not penetrate so deep into people’s lungs as combustion particles do.” (page 49)

He claims, without elaboration, that “Environmental damage due to lithium mining can be averted almost entirely.” (page 64) Near the end of the book, he states that “In a 2050 100 percent WWS world, WWS energy private costs equal WWS energy social costs because WWS eliminates all health and climate costs associated with energy.” (page 311; emphasis mine)

In a culture which holds continual economic growth to be sacred, it would be convenient to believe that business-as-usual can continue through 2050, with the only change required being a switch to WWS energy.

Imagine, then, that climate-changing emissions were the only critical flaw in the global economic system. Given that assumption, is Jacobson’s timetable for transition plausible?

No. First, Jacobson proposes that “by 2022”, no new power plants be built that use coal, methane, oil or biomass combustion; and that all new appliances for heating, drying and cooking in the residential and commercial sectors “should be powered by electricity, direct heat, and/or district heating.” (page 319) That deadline has passed, and products that rely on combustion continue to be made and sold. It is a mystery why Jacobson or his editors would retain a 2022 transition deadline in a book slated for publication in 2023.

Other sections of the timeline also strain credulity. “By 2023”, the timeline says, all new vehicles in the following categories should be either electric or hydrogen fuel-cell: rail locomotives, buses, nonroad vehicles for construction and agriculture, and light-duty on-road vehicles. This is now possible only in a purely theoretical sense. Batteries adequate for powering heavy-duty locomotives and tractors are not yet in production. Even if they were in production, and that production could be scaled up within a year, the charging infrastructure needed to quickly recharge massive tractor batteries could not be installed, almost overnight, at large farms or remote construction sites around the world.

While electric cars, pick-ups and vans now roll off assembly lines, the global auto industry is not even close to being ready to switch the entire product lineup to EV only. Unless, of course, they were to cut back auto production by 75% or more until production of EV motors, batteries, and charging equipment can scale up. Whether you think that’s a frightening prospect or a great idea, a drastic shrinkage in the auto industry would be a dramatic departure from a business-as-usual scenario.

What’s the harm, though, if Jacobson’s ambitious timeline is merely pushed back by two or three years?

If we were having this discussion in 2000 or 2010, pushing back the timeline by a few years would not be as consequential. But as Jacobson explains effectively in his outline of the climate crisis, we now need both drastic and immediate actions to keep cumulative carbon emissions low enough to avoid global climate catastrophe. His timeline is constructed with the goal of reducing carbon emissions by 80% by 2030, not because those are nice round figures, but because he (and many others) calculate that reductions of that scale and rapidity are truly needed. Even one or two more years of emissions at current rates may make the 1.5°C warming limit an impossible dream.

The picture is further complicated by a factor Jacobson mentions only in passing. He writes,

“During the transition, fossil fuels, bioenergy, and existing WWS technologies are needed to produce the new WWS infrastructure. … [A]s the fraction of WWS energy increases, conventional energy generation used to produce WWS infrastructure decreases, ultimately to zero. … In sum, the time-dependent transition to WWS infrastructure may result in a temporary increase in emissions before such emissions are eliminated.” (page 321; emphasis mine)

Others have explained this “temporary increase in emissions” at greater length. Assuming, as Jacobson does, that a “business-as-usual” economy keeps growing, the vast majority of goods and services will continue, in the short term, to be produced and/or operated using fossil fuels. If we embark on an intensive, global-scale, rapid build-out of WWS infrastructures at the same time, a substantial increment in fossil fuels will be needed to power all the additional mines, smelters, factories, container ships, trucks and cranes which build and install the myriad elements of a new energy infrastructure. If all goes well, that new energy infrastructure will eventually be large enough to power its own further growth, as well as to power production of all other goods and services that now rely on fossil energy.

Unless we accept a substantial decrease in non-transition-related industrial activity, however, the road that takes us to a full WWS destination must route us through a period of increased fossil fuel use and increased greenhouse gas emissions.

It would be great if Jacobson modeled this increase to give us some guidance how big this emissions bump might be, how long it might last, and therefore how important it might be to cumulative atmospheric carbon concentrations. There is no suggestion in this book that he has done that modeling. What should be clear, however, is that any bump in emissions at this late date increases the danger of moving past a climate tipping point – and this danger increases dramatically with every passing year.

1In a tl;dr version of No Miracles Needed published recently in The Guardian, Jacobson says “Worldwide, in fact, the energy that people use goes down by over 56% with a WWS system.” (“‘No miracles needed’: Prof Mark Jacobson on how wind, sun and water can power the world”, 23 January 2023)

 

Photo at top of page by Romain Guy, 2009; public domain, CC0 1.0 license, via Flickr.

Dreaming of clean green flying machines

Also published on Resilience

In common with many other corporate lobby groups, the International Air Transport Association publicly proclaims their commitment to achieving net-zero carbon emissions by 2050.1

Yet the evidence that such an achievement is likely, or even possible, is thin … to put it charitably. Unless, that is, major airlines simply shut down.

As a 2021 Nova documentary put it, aviation “is the high-hanging fruit – one of the hardest climate challenges of all.”2 That difficulty is due to the very essence of the airline business.

What has made aviation so attractive to the relatively affluent people who buy most tickets is that commercial flights maintain great speed over long distances. Aviation would have little appeal if airplanes were no faster than other means of transportation, or if they could be used only for relatively short distances. These characteristics come with rigorous energy demands.

A basic challenge for high-speed transportation – whether that’s pedaling a bike fast, powering a car fast, or propelling an airplane fast – is that the resistance from the air goes up with speed, not linearly but exponentially. As speed doubles, air resistance quadruples; as speed triples, air resistance increases by a factor of nine; and so forth.

That is one fundamental reason why no high-speed means of transportation came into use until the fossil fuel era. The physics of wind resistance become particularly important when a vehicle accelerates up to several hundred kilometers per hour or more.

Contemporary long-haul aircraft accommodate the physics in part by flying at “cruising altitude” – typically about 10,000 meters above sea level. At that elevation the atmosphere is thin enough to cause significantly less friction, while still rich enough in oxygen for combustion of the fuel. Climbing to that altitude, of course, means first fighting gravity to lift a huge machine and its passengers a very long way off the ground.

A long-haul aircraft, then, needs a high-powered engine for climbing, plus a large store of energy-dense fuel to last through all the hours of the flight. That represents a tremendous challenge for inventors hoping to design aircraft that are not powered by fossil fuels.

In Nova’s “The Great Electric Airplane Race”, the inherent problem is illustrated with this graphic:

graphic from Nova, “The Great Electric Airplane Race,” 26 May 2021

A Boeing 737 can carry up to 40,000 pounds of jet fuel. For the same energy content, the airliner would require 1.2 million pounds of batteries (at least several times the maximum take-off weight of any 737 model3). Getting that weight off the ground, and propelling it thousands of miles through the air, is obviously not going to work.

A wide variety of approaches are being tried to get around the drastic energy discrepancy between fossil fuels and batteries. We will consider several such strategies later in this article. First, though, we’ll take a brief look at the strategies touted by major airlines as important short-term possibilities.

“Sustainable fuel” and offsets

The International Air Transport Association gives the following roadmap for its commitment to net-zero by 2050. Anticipated emissions reductions will come in four categories:
3% – Infrastructure and operational efficiencies
13% – New technology, electric and hydrogen
19% – Offsets and carbon capture
65% – Sustainable Aviation Fuel

The tiny improvement predicted for “Infrastructure and operational efficiencies” reflects the fact that airlines have already spent more than half a century trying to wring the most efficiency out of their most costly input – fuel.

The modest emission reductions predicted to come from battery power and hydrogen reflects a recognition that these technologies, for all their possible strengths, still appear to be a poor fit for long-haul aviation.

That leaves two categories of emission reductions, “Offsets and carbon capture”, and “Sustainable Aviation Fuel”.

So-called Sustainable Aviation Fuel (SAF) is compatible with current jet engines and can provide the same lift-off power and long-distance range as fossil-derived aviation fuel. SAF is typically made from biofuel feedstocks such as vegetable oils and used cooking oils. SAF is already on the market, which might give rise to the idea that a new age of clean flight is just around the corner. (No further away, say, than 2050.)

Yet as a Comment piece in Nature* notes, only .05% of fuel currently used meets the definition of SAF.4 Trying to scale that up to meet most of the industry’s need for fuel would clearly result in competition for agricultural land. Since growing enough food to feed all the people on the ground is an increasingly difficult challenge, devoting a big share of agricultural production to flying a privileged minority of people through the skies is a terrible idea.5

In addition, it’s important to note that the burning of SAF still produces carbon emissions and climate-impacting contrails. The use of SAF is only termed “carbon neutral” because of the assumption that the biofuels are renewable, plant-based products that would decay and emit carbon anyway. That’s a dubious assumption, when there’s tremendous pressure to clear more forests, plant more hectares into monocultures, and mine soils in a rush to produce not only more food for people, but also more fuel for wood-fired electric generating stations, more ethanol to blend with gasoline, more biofuel diesel, and now biofuel SAF too. When SAF is scaled up, there’s nothing “sustainable” about it.

What about offsets? My take on carbon offsets is this: Somebody does a good thing by planting some trees. And then, on the off chance that these trees will survive to maturity and will someday sequester significant amounts of carbon, somebody offsets those trees preemptively by emitting an equivalent amount of carbon today.

Kallbekken and Victor’s more diplomatic judgement on offsets is this:

“The vast majority of offsets today and in the expected future come from forest-protection and regrowth projects. The track record of reliable accounting in these industries is poor …. These problems are essentially unfixable. Evidence is mounting that offsetting as a strategy for reaching net zero is a dead end.”6 (emphasis mine)

Summarizing the heavy reliance on offsetting and SAF in the aviation lobby’s net-zero plan, Kallbekken and Victor write “It is no coincidence that these ideas are also the least disruptive to how the industry operates today.” The IATA “commitment to net-zero”, basically, amounts to hoping to get to net-zero by carrying on with Business As Usual.

Contestants, start your batteries!

Articles appear in newspapers, magazines and websites on an almost daily basis, discussing new efforts to operate aircraft on battery power. Is this a realistic prospect? A particularly enthusiastic answer comes in an article from the Aeronautical Business School: “Electric aviation, with its promise of zero-emission flights, is right around the corner with many commercial projects already launched. …”7

Yet the electric aircraft now on the market or in prototyping are aimed at very short-haul trips. That reflects the reality that, in spite of intensive research and development in battery technology through recent decades, batteries are not remotely capable of meeting the energy and power requirements of large, long-haul aircraft.

The International Council on Clean Transportation (ICCT) recently published a paper on electric aircraft which shows why most flights are not in line to be electrified any time soon. Jayant Mukhopadhaya, one of the report’s co-authors, discusses the energy requirements of aircraft for four segments of the market. The following chart presents these findings: 

Table from Jayant Mukhopadhaya, “What to expect when expecting electric airplanes”, ICCT, July 14, 2022.

The chart shows the specific energy (“eb”, in Watt-hours per kilogram) and energy density (“vb”, in Watt-hours per liter) available in batteries today, plus the corresponding values that would be required to power aircraft in the four major market segments. Even powering a commuter aircraft, carrying 19 passengers up to 450 km, would require a 3-time improvement in specific energy of batteries.

Larger aircraft on longer flights won’t be powered by batteries alone unless there is a completely new, far more effective type of battery invented and commercialized:

“Replacing regional, narrowbody, and widebody aircraft would require roughly 6x, 9x, and 20x improvements in the specific energy of the battery pack. In the 25 years from 1991 to 2015, the specific energy and energy density of lithium-ion batteries improved by a factor of 3.”8

If the current rate of battery improvement were to continue for another 25 years, then, commuter aircraft carrying up to 19 passengers could be powered by batteries alone. That would constitute one very small step toward net-zero aviation – by the year 2047.

This perspective helps explain why most start-ups hoping to bring electric aircraft to market are targeting very short flights – from several hundred kilometers down to as little as 30 kilometers – and very small payloads – from one to five passengers, or freight loads of no more than a few hundred kilograms.

The Nova documentary “The Great Electric Airplane Race” took an upbeat tone, but most of the companies profiled, even if successful, would have no major impact on aviation’s carbon emissions.

Joby Aviation is touted as “the current leader in the race to fill the world with electric air taxis.” Their vehicles, which they were aiming to have certified by 2023, would carry a pilot and 4 passengers. A company called KittyHawk wanted to build an Electrical Vertical Take-Off and Landing (EVTOL) which they said could put an end to traffic congestion. The Chinese company Ehang was already offering unpiloted tourism flights, for two people and lasting no more than 10 minutes.

Electric air taxis, if they became a reality after 50 years of speculation, would result in no reductions in the emissions from the current aviation industry. They would simply be an additional form of energy-intensive mobility coming onto the market.

Other companies discussed in the Nova program were working on hybrid configurations. Elroy’s cargo delivery vehicle, for example, would have batteries plus a combustion engine, allowing it to carry a few hundred kilograms up to 500 km.

H2Fly, based in Stuttgart, was working on a battery/hydrogen hybrid. H2Fly spokesperson Joseph Kallo explained that “The energy can’t flow out of the [hydrogen fuel] cell as fast as it can from a fossil fuel engine or a battery. So there’s less power available for take-off. But it offers much more range.”

By using batteries for take-off, and hydrogen fuel cells at cruising altitude, Kallo said this technology could eventually work for an aircraft carrying up to 100 passengers with a range of 3500 km – though as of November 2020 they were working on “validating a range of nearly 500 miles”.

To summarize: electric and hybrid aviation technologies could soon power a few segments of the industry. As long as the new aircraft are replacing internal combustion engine aircraft, and not merely adding new vehicles on new routes for new markets, they could result in a small reduction in overall aviation emissions.

Yet this is a small part of the aviation picture. As Jayant Mukhopadhaya told treehugger.com in September,

“2.8% of departures in 2019 were for [flights with] less than 30 passengers going less than 200 km. This increases to 3.8% if you increase the range to 400 km. The third number they quote is 800 km for 25 passengers, which would then cover 4.1% of global departures.”9

This is roughly 3–4% of departures – but it’s important to recognize this does not represent 3–4% of global passenger km or global aviation emissions. When you consider that the other 96% of departures are made by much bigger planes, carrying perhaps 10 times as many passengers and traveling up to 10 times as far, it is clear that small-plane, short-hop aviation represents just a small sliver of both the revenue base and the carbon footprint of the airline industry.

Short-haul flights are exactly the kind of flights that can and should be replaced in many cases by good rail or bus options. (True, there are niche cases where a short flight over a fjord or other impassable landscape can save many hours of travel – but that represents a very small share of air passenger km.)

If we are really serious about a drastic reduction in aviation emissions, by 2030 or even by 2050, there is just one currently realistic route to that goal: we need a drastic reduction in flights.

* * *

Postscript: At the beginning of October a Washington Post article asked “If a Google billionaire can’t make flying cars happen, can anyone?” The article reported that KittyHawk, the EVTOL air taxi startup highlighted by Nova in 2021 and funded by Google co-founder Larry Page, is shutting down. The article quoted Peter Rez, from Arizona State University, explaining that lithium-ion batteries “output energy at a 50 times less efficient rate than their gasoline counterparts, requiring more to be on board, adding to cost and flying car and plane weight.” This story underscores, said the Post, “how difficult it will be to get electric-powered flying cars and planes.”

*Correction: The original version of this article attributed quotes from the Nature Comment article simply to “Nature”. Authors’ names have been added to indicate this is a signed opinion article and does not reflect an official editorial position of Nature.

Footnotes

1 IATA, “Our Commitment to Fly Net Zero by 2050”.

2 Nova, “The Great Electric Airplane Race” – 26 May 2021.

3 “The Difference In Weight Between The Boeing 737 Family’s Many Variants”, by Mark Finlay, April 24, 2022.

4  Steffen Kallbekken and David G. Victor, Nature, “A cleaner future for flight — aviation needs a radical redesign”, 16 September 2022.

5 Dan Rutherford writes, “US soy production contributes to global vegetable oil markets, and prices have spiked in recent years in part due to biofuel mandates. Diverting soy oil to jet fuel would put airlines directly in competition with food at a time when consumers are being hammered by historically high food prices.” In “Zero cheers for the supersoynic renaissance”, July 11, 2022.

6 Kallbekken and Victor, Nature, “A cleaner future for flight — aviation needs a radical redesign”, 16 September 2022.

7 “The path towards an environmentally sustainable aviation”, by Óscar Castro, March 23, 2022.

8 Jayant Mukhopadhaya, “What to expect when expecting electric airplanes”, ICCT, July 14, 2022.

9 “Air Canada Electrifies Its Lineup With Hybrid Planes”, by Lloyd Alter, September 20, 2022.


Photo at top of page: “Nice line up at Tom Bradley International Terminal, Los Angeles, November 10, 2013,” photo by wilco737, Creative Commons 2.0 license, on flickr.

‘This is a key conversation to have.’

This afternoon Post Carbon Institute announced the release of the new book Energy Transition and Economic Sufficiency. That brings to fruition a project more than two-and-a-half years in the making.

Cover of Energy Transition and Economic Sufficiency

In May 2019, I received an email from Clifford Cobb, editor of the American Journal of Economics and Sociology. He asked if I would consider serving as Guest Editor for an issue of the Journal, addressing “problems of transition to a world of climate instability and rising energy prices.” I said “yes” – and then, month by month, learned how difficult it can be to assemble a book-length collection of essays. In July, 2020, this was published by Wiley and made accessible to academic readers around the world.

It had always been a goal, however, to also release this collection as a printed volume, for the general public, at an accessible price. With the help of the Post Carbon Institute that plan is now realized. On their website you can download the book’s Introduction –which sets the context and gives an overview of each chapter – at no cost; download the entire book in pdf format for only $9.99US; or find online retailers around the world to buy the print edition of the book.

Advance praise for Energy Transition and Economic Sufficiency:

“Energy descent is crucial to stopping climate and ecological breakdown. This is a key conversation to have.” – Peter Kalmus, climate scientist, author of Being The Change

“This lively and insightful collection is highly significant for identifying key trends in transitioning to low-energy futures.” – Anitra Nelson, author of Small is Necessary

“The contributors to this volume have done us a tremendous service.” – Richard Heinberg, Senior Fellow, Post Carbon Institute, author of Power: Limits and Prospects for Human Survival

“For those already applying permaculture in their lives and livelihoods, this collection of essays is affirmation that we are on the right track for creative adaption to a world of less. This book helps fill the conceptual black hole that still prevails in academia, media, business and politics.” – David Holmgren, co-originator of Permaculture, author of RetroSuburbia

“The contributors explain why it is time to stop thinking so much about efficiency and start thinking about sufficiency: how much do we really need? What’s the best tool to do the job? What is enough? They describe a future that is not just sustainable but is regenerative, and where there is enough for everyone living in a low-carbon world.” – Lloyd Alter, Design Editor at treehugger.com and author of Living the 1.5 Degree Lifestyle: Why Individual Climate Action Matters More Than Ever

Some sources for the print edition:

In North America, Barnes & Noble

In Britain, Blackwell’s  and Waterstones

In Australia, Booktopia

Worldwide, from Amazon

Your gas tank is not an oil well. Your battery will not be a power plant.

Also published on Resilience.

My car comes with an amazing energy-storage, demand-management-and-supply system; perhaps you’ve heard of it. It’s called the “gas tank”.

Thanks to this revolutionary feature, if I get home and the electric grid is down, I can siphon gas out of the tank and power up a generator. In a more urgent energy crunch, I can siphon out some gas, throw it on a woodpile, and get a really hot fire going in seconds. If a friend across town has no power, I can even drive over there, siphon out some fuel, and run a generator to provide power in an alternate location. It’s beautiful! I can shift energy provision and consumption both temporally and spatially.

There is one minor drawback, to be sure. If I siphon the fuel out of the tank then I can’t actually drive the car, at least not more than a few kilometers to the nearest fuel station. But let’s not let that limitation cast a shadow over this revolutionary technology. If this flexible load-management system were widely adopted, and there were cars everywhere, think how smoothly our society could run!

These thoughts come to mind when I hear someone rhapsodize about the second coming of the electric car. Recently, for example, a Grist headline proclaimed that “Your Electric Vehicle Could Become a Mini Power Plant. And that could make the electrical grid work better for everyone.” (June 21, 2021)

Stephen Peake, in Renewable Energy: Ten Short Lessons (review here) wrote that “new fleets of electric vehicles parked overnight could become another mass source of electricity storage and supply.” (emphasis mine)

One more example: an Oct 2020 article at World Economic Forum says that “When electric vehicles are integrated into a city’s energy system, the battery can provide power to the grid when the sun is down or the wind isn’t blowing.”

The key to this supply-and-demand magic is “bidirectional charging” – the electric vehicles of the near future will have the equivalent of a gas tank with a built-in siphon. Thus their capacious batteries will not only be able to quickly suck power out of the grid, but also to empty themselves out again to provide juice for other purposes.

But allow me this skeptical observation: electric car batteries do not have huge batteries because the drivers want to offer aid to the “smart grid”. Electric car batteries are huge because cars are huge consumers of energy.

(True, electric cars don’t consume quite as much energy as internal-combustion cars of similar class and weight – but they consume a whole lot more energy per passenger/kilometer than intelligently routed electric buses, trains, or especially, electric-assisted bicycles.)

And let’s be clear: neither an electric car vehicle nor its battery provide any “energy supply”. The car itself is a pure energy suck. The battery is just an energy storage device – it can store a finite capacity of energy from another source, and output that energy as required, but it does not produce energy.

As with internal-combustion powered cars, when the tank/battery is drained for a purpose other than driving, then the car ceases to be a functional car until refueled.

That will leave some niche scenarios where vehicle batteries really might offer a significant advantage to grid supply management. The Grist article begins with one such scenario: three yellow school buses which run on battery power through the school year, and serve as a battery bank while parked for the summer months. If all 8,000 school buses in the local utility service area were EVs, the article notes, their fully-charged batteries “could collectively supply more than 100 megawatts of power to the grid for short periods — or nearly 1 percent of Con Ed’s peak summer power demand.”

When parked for the summer, electric school buses would not need to be charged and ready to drive first thing every weekday morning. So they could indeed be used simply as (terribly expensive) battery cases for two or three months each year.

OK, but … let’s be careful about singing the praises of school buses. This might be a slippery slope. If big buses catch on, soon Americans might start taking their kids to school in giant pick-up trucks!

Of course I jest – that horse has already left the barn. The top three selling vehicles in the US, it may surprise people from elsewhere to learn, are pick-up trucks that dwarf the pick-ups used by farmers and some tradespeople in previous generations. (It will not surprise Canadians, who play second fiddle to no-one in car culture madness. Canadians tend to buy even larger, heavier, more powerful, and more expensive trucks than Americans do.)

The boom in overgrown pick-ups has not come about because North Americans are farming and logging in record numbers, nor even, as one wag put it, that a 4X8 sheet of plywood has gotten so much bigger in recent years. Yet urban streets, parking lots, and suburban driveways are now crowded with hulking four-door, four-wheel-drive, spotlessly clean limousine-trucks. Those vehicles, regardless of their freight-carrying or freight-pulling capacity, are used most to carry one or two people around urbanized areas.

If we are foolish enough to attempt electrification of this fleet, it will take an awesome amount of battery power. And as you might expect, car culture celebrants are already proclaiming what a boon this will be for energy transition.

A pre-production promo video for Ford’s F-150 Lightning electric pick-up truck gets to the critical issue first: the Lightning will accelerate from 0 – 60 mph (0 – 97 km/hr) “in the mid-4-second range”. But wait, there’s more, the ad promises: the battery can “off-board” enough power to run a home “for about three days”.

Keep that in mind when you start seeing big electric pick-up trucks on the road: each one, in just a few hours of highway driving, will use as much power as a typical American home uses in three days.

Keep it in mind, too, when you see a new bank of solar panels going up in a field or on a warehouse roof: the installation might output enough electricity each day to power 100 pickup trucks for a few hours each – or 300 homes for the whole day.

Given that we won’t have enough renewably produced electricity to power existing homes, schools, stores and industries for decades, is it really a good idea to devote a big share of it, right at the outset, to building and charging limousine-trucks? Are the huge batteries required by these vehicles actually features, or are they bugs?

Granted, an electric car battery can provide a modest degree of grid load-levelling capability in some situations. It can be drained back into the grid during some peak-power-demand periods such as early evening in the heat of summer – as long as it can be recharged in time for the morning commute. That’s not nothing. And if we’re determined to keep our society moving by using big cars and trucks, that means we’ll have a huge aggregated battery capacity sitting in parking spots for most of each day. In that scenario, sure, there will be a modest degree of load-levelling capacity in those parked vehicles.

But perhaps there is a better way to add load-levelling capacity to the grid. A better way than producing huge, heavy vehicles, each containing one battery, which suck up that power fast whenever they’re being driven, while also spreading brake dust and worn tire particles through the environment, and which significantly increase the danger to vulnerable road users besides. Not to mention, which result in huge upfront emissions of carbon dioxide during their manufacture.

If it’s really load-levelling we’re after, for the same money and resources we could build a far greater number of batteries, and skip building expensive casings in the form of cars and pick-ups.

Other factors being equal, an electric car is modestly more environmentally friendly than internal-combustion car. (How’s that for damning with faint praise?)  But if we’re ready for a serious response to the climate emergency, we should be rapidly curtailing both the manufacture and use of cars, and making the remaining vehicles only as big and heavy as they actually need to be. The remaining small cars won’t collectively contain such a huge battery capacity, to be sure, but we can then address the difficult problems of grid load management in a more intelligent, efficient and direct fashion.

Illustration at top of post: Energy Utopia, composite by Bart Hawkins Kreps from public domain images.

Sunshine, wind, tides and worldwatts

A review of Renewable Energy: Ten Short Lessons

Also published on Resilience

Fun physics fact: water carries so much more kinetic energy than air that “A tidal current of 3 knots has the same energy density as a steady wind stream at 29 knots (a fair old blow).”

And consider this: “Ninety-nine per cent of planet Earth is hotter than 1,000 °C (1,832 °F). The earth is, in fact, a giant leaky heat battery.”

Stephen Peake uses these bits of information and many more to lucidly outline the physical bases of renewable energy sources, including solar and wind energy, geothermal energy, wave energy and tidal current energy. But the book also touches on the complex relationship between the physics of renewable energy, and the role energy plays in human society – and the results aren’t always enlightening.

Peake takes on a formidable task in Renewable Energy: Ten Short Lessons. The book is part of the “Pocket Einstein” series from Johns Hopkins University Press (or from Michael O’Mara Books in Britain). He has less than 200 small-format pages in which to cover both the need for and the prospects for a transition to 100% renewable energy.

Key to his method is the concept of a “worldwatt” – “the rate at which the world uses all forms of primary energy.” Peake estimates the rate of energy flow around the world from various potential renewable energy sources. Not surprisingly, he finds that the theoretically available renewable energy sources are far greater than all energy currently harnessed – primarily from fossil fuels – by the global economy.

But how do we get from estimates of theoretically available energy, to estimates of how much of that energy is practically and economically available? Here Peake’s book isn’t much help. He asks us to accept this summation:

“Taking a conservative mid-estimate of the numbers in the literature, we see that the global technical potential of different renewable sources adds up to 46 worldwatts. There is a definite and reasonable prospect of humans harnessing 1 worldwatt from 100 per cent renewable energy in the future.” (page 31)

But he offers no evidence or rationale for the conclusion that getting 1 worldwatt from renewable sources is a “reasonable prospect”, nor how near or far “in the future” that might occur.

A skeptic might well dismiss the book as renewable energy boosterism, noting a cheery optimism from the opening pages: “There is an exciting, renewable, electric, peaceful, prosperous, safer future just up ahead.” Others might say such optimism is the most helpful position one can take, given that we have no choice but to switch to a renewable energy way of life, ASAP, if we want human presence on earth to last much longer.

Yet a cheerfully pro-renewable energy position can easily shade into a cheerful pro-consumptionist stance – the belief that renewable energies can quickly become the driving force of our current industrial economies, with little change in living standards and no end to economic growth.

Peake briefly introduces a key concept for assessing which renewable energy sources will be economically viable, and in what quantities: Energy Return On Energy Invested (EROEI). He explains that as we exploit more difficult energy sources, the EROEI goes down:

“As wind turbines have become larger and moved offshore, the EROEI ratio for wind over a twenty-year lifetime has declined from around 20:1 in the early 2000s to as low as 15:1 in recent years for some offshore wind farms.” (page 84)

Affordable renewable energy, in other words, doesn’t always “scale up”. The greater the total energy demanded by society, the more we will be impelled to site wind turbines and solar panels in areas beyond the “sweet spots” for Energy Return On Energy Invested. Peake’s book would be stronger if he used this recognition to give better context to statements such as “Renewable electricity is now cheaper than fossil electricity …” (in the book’s opening paragraph), and “solar is now the cheapest electricity in history” (page 70).

While Peake expresses confidence that a prosperous renewable energy world is just ahead, he doesn’t directly engage with the issue of how, or how much, affluent lifestyles may need to change. The closest he comes to grappling with this contentious issue is in his discussion of energy waste:

“We need to stop wasting all forms of energy, including clean renewable sources of heat and electricity. The sooner we shrink our total overall demand for energy, the sooner renewables will be able to provide 100 per cent of the energy we need to power our zero-carbon economies.” (page 141)

Near the end of the book, in brief remarks about electric cars, Peake makes some curious statements about EVs:

“Millions of [electric vehicles] will need charging from the network. This presents both a challenge and an opportunity in terms of managing the network load.” (page 130, emphasis mine)

And a few pages later:

“In the future, new fleets of electric vehicles parked overnight could become another mass source of electricity storage and supply.” (page 134 emphasis mine)

In my next post I’ll take up this concept of the electric vehicle as energy storage, supply and load management resource.

In conclusion, Renewable Energy: Ten Short Lessons is a valuable primer on the physics of renewable energy, but isn’t a lot of help in establishing whether or not the existing world economy can be successfully transitioned to zero-carbon energy.

Photo at top of page: Wind Turbines near Grevelingenmeer, province of Zeeland, Netherlands

 

Transition to a Low-Energy Future

One project has taken the lion’s share of my work time for the past year, and it has been a project close to my heart.

As long-time readers will have noted, my writings frequently concern the intersection between energy and economics. I was honored and grateful, therefore, to be asked to serve as guest editor of an issue of The American Journal of Economics and Sociology.

After a year’s work this issue is now published, under the title “Transition to a Low-Energy Future”. An issue overview and all individual articles can be found here.

I am now working on the next phase of this project – seeing this published as a generally-available print book. Inquiries and comments on this project are most welcome; please get in touch through the Contact page on this website.

Energy storage and our unpredictable future

A review of Energy Storage and Civilization

Also published on Resilience.org

It’s a fine spring day and you decide on a whim to go camping. By early afternoon you’ve reached a sheltered clearing in the woods, the sky is clear, and you relax against a tree trunk rejoicing that “The best things in life are free!” as you soak up the abundant warmth of the sun. As the sun goes down, though, the temperature drops to near freezing, you shiver through a long night, and you resolve to be better prepared the next night.

And so by the time the sun sets again you’ve invested in a good down sleeping bag, you sleep through the long night in comfort due to your own carefully retained heat, and then you greet the cold dawn by cheerfully striking a match to the pile of dry sticks you had gathered and stacked the day before.

In this little excursion you’ve coped with variable energy flows, using technologies that allowed you to store energy for use at a later time. In short, you’ve faced the problems that Graham Palmer and Joshua Floyd identify as critical challenges in all human civilizations – and especially in our own future.

Their new book Energy Storage and Civilization: A Systems Approach (Springer, February 2020) is an important contribution to biophysical economics – marvelously clear, deep and detailed where necessary, and remarkably thorough for a work of just over 150 pages.

The most widely appreciated insight of biophysical economics is the concept of Energy Return On Investment – the need for energy technologies to yield significantly more energy than the energy that must be invested in these activities. (If it takes more energy to drill an oil well than the resulting barrels of oil can produce, that project is a bust.) While in no way minimizing the importance of EROI, Palmer and Floyd lay out their book’s purpose succinctly:

“we want to argue that energy storage, as both a technological and natural phenomenon, has been much more significant to the development of human civilizations than usually understood.” (Energy Storage and Civilization, page 2)

Central to their project is the distinction between energy stocks and energy flows. Sunshine and wind energy – primary energy sources in a renewable energy future – are energy flows. Grains, butter, wood, coal, oil and natural gas are energy stocks. And storage mediates between the two:

“Energy storage deals with the relationship between stocks and flows: storing energy, whether by natural or anthropic processes, involves the accumulation of flows as stocks; exploiting stored energy involves the conversion of stocks to flows.” (page 1)

Our current industrial civilization relies on the vast quantities of energy stored in our one-time inheritance of fossil fuels. These energy stocks allow us to consume energy anywhere on earth, at any hour and in any season. If the limited supplies of readily accessible fossil fuels weren’t running out, and if their burning weren’t destabilizing the climate and threatening the entire web of life, we might think we had discovered the secret of civilizational eternal youth.

Fossil fuels are higher in energy density than any previous energy stock at our control. That energy density means we can ship and store these stocks for use across great distances and long periods. Oil is so easy to ship that it is traded worldwide and is fundamental to the entire global economy.

In particular, fossil fuel stocks can be readily converted to electrical energy flows. And electricity, which is so magnificently versatile that it too is fundamental to the global economy, cannot be stored in any significant quantity without being converted to another energy form, and then converted back at time of use – at significant cost in energy losses and further costs for the storage technologies.

This is the crux of the problem, Palmer and Floyd explain. The vision of a renewable energy economy relies on use of solar PV and wind turbines to generate all our electricity – plus electrification of systems like transportation, which now rely directly on fossil fuel combustion engines. A major part of the book deals with two closely related questions: How much storage would we need to manage current energy demand with the highly intermittent flows of solar and wind energy? and, Are there feasible methods known today which could create those quantities of energy storage?

Beyond simple technologies like huge tanks or reservoirs of oil and gas, and stockpiles of coal, our current economy has little need for complicated means of energy storage. Batteries, while essential for niche uses in phones and computers, store only tiny amounts of electrical energy. But in Palmer and Floyd’s estimations, to maintain an economy with today’s energy consumption without fossil fuels, we will need to expand “current technologically-mediated storage capacity by three orders of magnitude”. (page 28)

What might a thousand-fold or greater expansion of storage technology look like? Palmer and Floyd provide some excellent illustrations. Pumped hydro storage is one promising candidate for managing the intermittent energy flows of solar PV or wind generators. Where suitable sites exist, surplus electricity can be used to pump water to an elevated reservoir, and then when the sun goes down or the wind calms, the water can flow down through turbines to regenerate electricity. This is a simple process, requiring two water reservoirs that are close geographically but at significantly different elevations, and is already used in some niche markets.

But for pumped hydro storage to be a primary means of managing intermittent renewable electricity production – that’s another story. By Palmer and Floyd’s calculations, to produce half of current US peak electricity demand via pumped hydro storage, the combined water flow from all the upper reservoirs would need to be far greater than the typical flow of the Mississippi River, and closer to the total flow of the Amazon River (depending on the average elevation differences between the reservoir pairs).

Comparison of required Pumped Hydro Storage flow to major river flows (by Graham Palmer and Joshua Floyd, from Energy Storage and Civilization: A Systems Approach, page 143). This amount of Pumped Hydro Storage would be needed to meet half of current US peak electricity demand.

Building sufficient battery storage is equally daunting. Palmer and Floyd look at the challenge of converting the world’s gas- and diesel-powered passenger vehicles to battery-electric propulsion. Even after making appropriate allowance for the far greater “tank-to-wheels” efficiency of electric motors, they find that to replace the energy storage capacity now held in the vehicles’ fuel tanks, we would need battery storage equivalent to 142 TWh (TeraWatt hours). As shown in Palmer and Floyd’s illustration below, the key material requirements for that many batteries are vast, in some cases greater than the entire current world reserves. And that is to say nothing of the energy costs of acquiring the materials and building the batteries, or the even more difficult problems of electrifying heavy freight vehicles.

Material requirements for batteries for world’s fleet of passenger vehicles (by Graham Palmer and Joshua Floyd, from Energy Storage and Civilization: A Systems Approach, page 141). To match the deliverable energy stored in the fuel tanks, battery production would consume huge quantities of key materials – in some cases exceeding the current world reserves.

Barring unknown and therefore unforeseeable possible developments in storage technologies that might provide order-of-magnitude improvements, then, it is highly unrealistic to expect that we can simply replace current world energy demands from renewable energy sources. Far greater changes are likely: combinations of changes in technologies, trading practices, regulations, social practices, ways of life. The layers of interacting complexity, Palmer and Floyd argue, are beyond the capacity of computer models to predict.

Their book is a bit of a complex system, too. Although many of the ideas they present are simple and they explain them well, there are sections which go beyond “challenging” for readers who have no more than an ancient memory of high-school-level chemistry and physics. (I plead guilty.) Such readers will nevertheless be rewarded by persevering through difficult parts, because Palmer and Floyd do such a good job of tying all the strands together. The second-to-last chapter, for example, provides a lucid explanation of why the “hydrogen economy” offers real potential for replacing some of the energy storage and transport capacities of fossil fuels – while incurring very significant energy conversion penalties that would have major economic implications.

Civilizations both ancient and contemporary need practices that provide a sufficient Energy Return On Investment – but a high EROI is not sufficient cause for a technology or practice to come into wide use. Rather, we need complete socio-technical systems that provide the right combination of adequate EROI, and adequate and flexible energy storage.

Energy Storage and Civilization is a superb overview of these challenges for the waning years of fossil fuel civilization.


Photo at top by Radek Grzybowski – A stack of wood lays in front of a snowy and foggy forest, Gliwice, Poland; from Wikimedia Commons.

Platforms for a Green New Deal

Two new books in review

Also published on Resilience.org

Does the Green New Deal assume a faith in “green growth”? Does the Green New Deal make promises that go far beyond what our societies can afford? Will the Green New Deal saddle ordinary taxpayers with huge tax bills? Can the Green New Deal provide quick solutions to both environmental overshoot and economic inequality?

These questions have been posed by people from across the spectrum – but of course proponents of a Green New Deal may not agree on all of the goals, let alone an implementation plan. So it’s good to see two concise manifestos – one British, one American – released by Verso in November.

The Case for the Green New Deal (by Ann Pettifor), and A Planet to Win: Why We Need a Green New Deal (by Kate Aronoff, Alyssa Battistoni, Daniel Aldana Cohen and Thea Riofrancos) each clock in at a little under 200 pages, and both books are written in accessible prose for a general audience.

Surprisingly, there is remarkably little overlap in coverage and it’s well worth reading both volumes.

The Case for a Green New Deal takes a much deeper dive into monetary policy. A Planet To Win devotes many pages to explaining how a socially just and environmentally wise society can provide a healthy, prosperous, even luxurious lifestyle for all citizens, once we understand that luxury does not consist of ever-more-conspicuous consumption.

The two books wind to their destinations along different paths but they share some very important principles.

Covers of The Case For The Green New Deal and A Planet To Win

First, both books make clear that a Green New Deal must not shirk a head-on confrontation with the power of corporate finance. Both books hark back to Franklin Delano Roosevelt’s famous opposition to big banking interests, and both books fault Barack Obama for letting financial kingpins escape the 2008 crash with enhanced power and wealth while ordinary citizens suffered the consequences.

Instead of seeing the crash as an opportunity to set a dramatically different course for public finance, Obama presented himself as the protector of Wall Street:

“As [Obama] told financial CEOs in early 2009, “My administration is the only thing between you and the pitchforks.” Frankly, he should have put unemployed people to work in a solar-powered pitchfork factory.” (A Planet To Win, page 13)

A second point common to both books is the view that the biggest and most immediate emissions cuts must come from elite classes who account for a disproportionate share of emissions. Unfortunately, neither book makes it clear whether they are talking about the carbon-emitting elite in wealthy countries, or the carbon-emitting elite on a global scale. (If it’s the latter, that likely includes the authors, most of their readership, this writer and most readers of this review.)

Finally, both books take a clear position against the concept of continuous, exponential economic growth. Though they argue that the global economy must cease to grow, and sooner rather than later, their prescriptions also appear to imply that there will be one more dramatic burst of economic growth during the transition to an equitable, sustainable steady-state economy.

Left unasked and unanswered in these books is whether the climate system can stand even one more short burst of global economic growth.

Public or private finance

The British entry into this conversation takes a deeper dive into the economic policies of US President Franklin Roosevelt. British economist Ann Pettifor was at the centre of one of the first policy statements that used the “Green New Deal” moniker, just before the financial crash of 2007–08. She argues that we should have learned the same lessons from that crash that Roosevelt had to learn from the Depression of the 1930s.

Alluding to Roosevelt’s inaugural address, she summarizes her thesis this way:

“We can afford what we can do. This is the theme of the book in your hands. There are limits to what we can do – notably ecological limits, but thanks to the public good that is the monetary system, we can, within human and ecological limits, afford what we can do.” (The Case for the Green New Deal, page xi)

That comes across as a radical idea in this day of austerity budgetting. But Pettifor says the limits that count are the limits of what we can organize, what we can invent, and, critically, what the ecological system can sustain – not what private banking interests say we can afford.

In Pettifor’s view it is not optional, it is essential for nations around the world to re-win public control of their financial systems from the private institutions that now enrich themselves at public expense. And she takes us through the back-and-forth struggle for public control of banking, examining the ground-breaking theory of John Maynard Keynes after World War I, the dramatically changed monetary policy of the Roosevelt administration that was a precondition for the full employment policy of the original New Deal, and the gradual recapture of global banking systems by private interests since the early 1960s.

On the one hand, a rapid reassertion of public banking authority (which must include, Pettifor says, tackling the hegemony of the United States dollar as the world’s reserve currency) may seem a tall order given the urgent environmental challenges. On the other hand, the global financial order is highly unstable anyway, and Pettifor says we need to be ready next time around:

“sooner rather than later the world is going to be faced by a shuddering shock to the system. … It could be the flooding or partial destruction of a great city …. It could be widespread warfare…. Or it could be (in my view, most likely) another collapse of the internationally integrated financial system. … [N]one of these scenarios fit the ‘black swan’ theory of difficult-to-predict events. All three fall within the realm of normal expectations in history, science and economics.” (The Case for the Green New Deal, pg 64)

A final major influence acknowledged by Pettifor is American economist Herman Daly, pioneer of steady-state economics. She places this idea at the center of the Green New Deal:

“our economic goal is for a ‘steady state’ economy … that helps to maintain and repair the delicate balance of nature, and respects the laws of ecology and physics (in particular thermodynamics). An economy that delivers social justice for all classes, and ensures a liveable planet for future generations.” (The Case for the Green New Deal, pg 66)

Beyond a clear endorsement of this principle, though, Pettifor’s book doesn’t offer much detail on how our transportation system, food provisioning systems, etc, should be transformed. That’s no criticism of the book. Providing a clear explanation of the need for transformation in monetary policy; why the current system of “free mobility” of capital allows private finance to work beyond the reach of democratic control, with disastrous consequences for income equality and for the environment; and how finance was brought under public control before and can be again – this  is a big enough task for one short book, and Pettifor carries it out with aplomb.

Some paths are ruinous. Others are not.

Writing in The Nation in November of 2018, Daniel Aldana Cohen set out an essential corrective to the tone of most public discourse:

“Are we doomed? It’s the most common thing people ask me when they learn that I study climate politics. Fair enough. The science is grim, as the UN Intergovernmental Panel on Climate Change (IPCC) has just reminded us with a report on how hard it will be to keep average global warming to 1.5 degrees Celsius. But it’s the wrong question. Yes, the path we’re on is ruinous. It’s just as true that other, plausible pathways are not. … The IPCC report makes it clear that if we make the political choice of bankrupting the fossil-fuel industry and sharing the burden of transition fairly, most humans can live in a world better than the one we have now.” (The Nation, “Apocalyptic Climate Reporting Completely Misses the Point,” November 2, 2018; emphasis mine)

There’s a clear echo of Cohen’s statement in the introduction to A Planet To Win:

“we rarely see climate narratives that combine scientific realism with positive political and technological change. Instead, most stories focus on just one trend: the grim projections of climate science, bright reports of promising technologies, or celebrations of gritty activism. But the real world will be a mess of all three. (A Planet To Win, pg 3)

The quartet of authors are particularly concerned to highlight a new path in which basic human needs are satisfied for all people, in which communal enjoyment of public luxuries replaces private conspicuous consumption, and in which all facets of the economy respect non-negotiable ecological limits.

The authors argue that a world of full employment; comfortable and dignified housing for all; convenient, cheap or even free public transport; healthy food and proper public health care; plus a growth in leisure time –  this vision can win widespread public backing and can take us to a sustainable civilization.

A Planet To Win dives into history, too, with a picture of the socialist housing that has been home to generations of people in Vienna. This is an important chapter, as it demonstrates that there is nothing inherently shabby in the concept of public housing:

“Vienna’s radiant social housing incarnates its working class’s socialist ideals; the United States’ decaying public housing incarnates its ruling class’s stingy racism.” (A Planet To Win, pg 127)

Likewise, the book looks at the job creation programs of the 1930s New Deal, noting that they not only built a vast array of public recreational facilities, but also carried out the largest program of environmental restoration ever conducted in the US.

The public co-operatives that brought electricity to rural people across the US could be revitalized and expanded for the era of all-renewable energy. Fossil fuel companies, too, should be brought under public ownership – for the purpose of winding them down as quickly as possible while safeguarding workers’ pensions.

In their efforts to present a New Green Deal in glowingly positive terms, I think the authors underestimate the difficulties in the energy transition. For example, they extol a new era in which Americans will have plenty of time to take inexpensive vacations on high-speed trains throughout the country. But it’s not at all clear, given current technology, how feasible it will be to run completely electrified trains through vast and sparsely populated regions of the US.

In discussing electrification of all transport and heating, the authors conclude that the US must roughly double the amount of electricity generated – as if it’s a given that Americans can or should use nearly as much total energy in the renewable era as they have in the fossil era.1

And once electric utilities are brought under democratic control, the authors write, “they can fulfill what should be their only mission: guaranteeing clean, cheap, or even free power to the people they serve.” (A World To Win, pg 53; emphasis mine)

A realistic understanding of thermodynamics and energy provision should, I think, prompt us to ask whether energy is ever cheap or free – (except in the dispersed, intermittent forms of energy that the natural world has always provided).

As it is, the authors acknowledge a “potent contradiction” in most current recipes for energy transition:

“the extractive processes necessary to realize a world powered by wind and sun entail their own devastating social and environmental consequences. The latter might not be as threatening to the global climate as carbon pollution. But should the same communities exploited by 500 years of capitalist and colonial violence be asked to bear the brunt of the clean energy transition …?” (A Planet To Win, pg 147-148)

With the chapter on the relationship between a Green New Deal in the industrialized world, and the even more urgent challenges facing people in the Global South, A World To Win gives us an honest grappling with another set of critical issues. And in recognizing that “We hope for greener mining techniques, but we shouldn’t count on them,” the authors make it clear that the Green New Deal is not yet a fully satisfactory program.

Again, however, they accomplish a lot in just under 200 pages, in support of their view that “An effective Green New Deal is also a radical Green New Deal” (A Planet To Win, pg 8; their emphasis). The time has long passed for timid nudges such as modest carbon taxes or gradual improvements to auto emission standards.

We are now in “a trench war,” they write, “to hold off every extra tenth of a degree of warming.” In this war,

“Another four years of the Trump administration is an obvious nightmare. … But there are many paths to a hellish earth, and another one leads right down the center of the political aisle.” (A Planet To Win, pg 180)

1 This page on the US government Energy Information Agency website gives total US primary energy consumption as 101 quadrillion Btus, and US electricity use as 38 quadrillion Btus. If all fossil fuel use were stopped but electricity use were doubled, the US would then use 76 quadrillion Btus, or 75% of current total energy consumption.

Questions as big as the atmosphere

A review of After Geoengineering

Also published at Resilience.org

After Geoengineering is published by Verso Books, Oct 1 2019.

What is the best-case scenario for solar geoengineering? For author Holly Jean Buck and the scientists she interviews, the best-case scenario is that we manage to keep global warming below catastrophic levels, and the idea of geoengineering quietly fades away.

But before that can happen, Buck explains, we will need heroic global efforts both to eliminate carbon dioxide emissions and to remove much of the excess carbon we have already loosed into the skies.

She devotes most of her new book After Geoengineering: Climate Tragedy, Repair, and Restoration to proposed methods for drawing down carbon dioxide levels from the atmosphere. Only after showing the immense difficulties in the multi-generational task of carbon drawdown does she directly discuss techniques and implications of solar geoengineering (defined here as an intentional modification of the upper atmosphere, meant to block a small percentage of sunlight from reaching the earth, thereby counteracting part of global heating).

The book is well-researched, eminently readable, and just as thought-provoking on a second reading as on the first. Unfortunately there is little examination of the way future energy supply constraints will affect either carbon drawdown or solar engineering efforts. That significant qualification aside, After Geoengineering is a superb effort to grapple with some of the biggest questions for our collective future.

Overshoot

The fossil fuel frenzy in the world’s richest countries has already put us in greenhouse gas overshoot, so some degree of global heating will continue even if, miraculously, there were an instant political and economic revolution which ended all carbon dioxide emissions tomorrow. Can we limit the resulting global heating to 1.5°C? At this late date our chances aren’t good.

As Greta Thunberg explained in her crystal clear fashion to the United Nations Climate Action Summit:

“The popular idea of cutting our emissions in half in 10 years only gives us a 50% chance of staying below 1.5C degrees, and the risk of setting off irreversible chain reactions beyond human control.

“Maybe 50% is acceptable to you. But those numbers don’t include tipping points, most feedback loops, additional warming hidden by toxic air pollution or the aspects of justice and equity. They also rely on my and my children’s generation sucking hundreds of billions of tonnes of your CO2 out of the air with technologies that barely exist.” 1

As Klaus Lackner, one of the many researchers interviewed by Buck, puts it, when you’ve been digging yourself into a hole, of course the first thing you need to do is stop digging – but then you still need to fill in the hole.2

How can we fill in the hole – in our case, get excess carbon back out of the atmosphere? There are two broad categories, biological processes and industrial processes, plus some technologies that cross the lines. Biological processes include regenerative agriculture and afforestation while industrial processes are represented most prominently by Carbon Capture and Sequestration (CCS).

Buck summarizes key differences this way:

“Cultivation is generative. Burial, however, is pollution disposal, is safety, is sequestering something away where it can’t hurt you anymore. One approach generates life; the other makes things inert.” (After Geoengineering (AG), page 122)

Delving into regenerative agriculture, she notes that “over the last 10,000 years, agriculture and land conversion has decreased soil carbon globally by 840 gigatons, and many cultivated soils have lost 50 to 70 percent of their original organic carbon” (AG, p 101).

Regenerative agriculture will gradually restore that carbon content in the soil and reduce carbon dioxide in the air – while also making the soil more fertile, reducing wind and water erosion, increasing the capacity of the soil to stay healthy when challenged by extreme rainfalls or drought, and making agriculture ecologically sustainable in contrast to industrial agriculture’s ongoing stripping the life from soil.

Regenerative agriculture cannot, however, counteract the huge volumes of excess carbon dioxide we are currently putting into the atmosphere. And even when we have cut emissions to zero, Buck writes, regenerative agriculture is limited in how much of the excess carbon it can draw down:

“soil carbon accrual rates decrease as stocks reach a new equilibrium. Sequestration follows a curve: the new practices sequester a lot of carbon at first, for the first two decades or so, but this diminishes over time toward a new plateau. Soil carbon sequestration is therefore a one-off method of carbon removal.” (AG, p 102)

There are other types of cultivation that can draw down carbon dioxide, and Buck interviews researchers in many of these fields. The planting of billions of trees has received the most press, and this could store a lot of carbon. But it also takes a lot of land, and it’s all too easy to imagine that more frequent and fiercer wildfires could destroy new forests just when they have started to accumulate major stores of carbon.

Biochar – the burying of charcoal in a way that stores carbon for millennia while also improving soil fertility – was practiced for centuries by indigenous civilizations in the Amazon. Its potential on a global scale is largely untapped but is the subject of promising research.

In acknowledging the many uncertainties in under-researched areas, Buck does offer some slender threads of hope here. Scientists say that “rocks for crops” techniques – in which certain kinds of rock are ground up and spread on farmland – could absorb a lot of carbon while also providing other soil nutrients. In the lab, the carbon absorption is steady but geologically slow, but there is some evidence that in the real world, the combined effects of microbes and plant enzymes may speed up the weathering process by at least an order of magnitude. (AG, p 145-146)

The cultivation methods offer a win-win-win scenario for carbon drawdown – but we’re on pace to a greenhouse gas overshoot that will likely dwarf the drawdown capacity of these methods. Buck estimates that cultivation methods, at the extremes of their potential, could sequester perhaps 10 to 20 gigatons (Gt) of carbon dioxide per year (and that figure would taper off once most agricultural soils had been restored to a healthy state). That is unlikely to be anywhere near enough:

“Imagine that emissions flatline in 2020; the world puts in a strong effort to hold them steady, but it doesn’t manage to start decreasing them until 2030. … But ten years steady at 50 Gt CO2 eq [carbon dioxide equivalent emissions include other gases such as methane] – and there goes another 500 Gt CO2 eq into the atmosphere. That one decade would cancel out the 500 Gt CO2 eq the soils and forests could sequester over the next 50 years (sequestered at an extreme amount of effort and coordination among people around the whole world).” (AG p 115)

With every year that we pump out fossil fuel emissions, then, we compound the intergenerational crime we have already committed against Greta Thunberg and her children’s generations. With every year of continued emissions, we increase the probability that biological, generative methods of carbon drawdown will be too slow. With every year of continued emissions, we increase the degree to which future generations will be compelled to engage in industrial carbon drawdown work, using technologies which do not enrich the soil, which produce no food, which will not directly aid the millions of species struggling for survival, and which will suck up huge amounts of energy.

Carbon Capture and Sequestration

Carbon Capture and Sequestration (CCS) has earned a bad name for good reasons. To date most CCS projects – even those barely past the concept stage – have been promoted by fossil fuel interests. CCS projects offer them research subsidies for ways to continue their fossil fuel businesses, plus a public relations shine as proponents of “clean” energy.

A lignite mine in southwest Saskatchewan. This fossil fuel deposit is home to one of the few operating Carbon Capture and Sequestration projects. Carbon from a coal-fired generating station is captured and pumped into a depleting oil reservoir – for the purpose of prolonging petroleum production.

Buck argues that in spite of these factors, we need to think about CCS technologies separate from their current capitalist contexts. First of all, major use of CCS technologies alongside continued carbon emissions would not be remotely adequate – we will need to shut off carbon emissions AND draw down huge amounts of carbon from the atmosphere. And there is no obvious way to fit an ongoing, global program of CCS into the framework of our current corporatocracy.

The fossil fuel interests possess much of the technical infrastructure that could be used for CCS, but their business models rely on the sale of polluting products. So if CCS is to be done in a sustained fashion, it will need to be done in a publicly-funded way where the service, greenhouse gas drawdown, is for the benefit of the global public (indeed, the whole web of life, present and future); there will be no “product” to sell.

However CCS efforts are organized, they will need to be massive in order to cope with the amounts of carbon emissions that fossil fuel interests are still hell-bent on releasing. In the words of University of Southern California geologist Joshua West,

“The fossil fuels industry has an enormous footprint …. Effectively, if we want to offset that in an industrial way, we have to have an industry that is of equivalent proportion ….” (AG, p 147)

Imagine an industrial system that spans the globe, employing as many people and as much capital as the fossil fuel industries do today. But this industry will produce no energy, no wealth, no products – it will be busy simply managing the airborne refuse bequeathed by a predecessor economy whose dividends have long since been spent.

So while transitioning the entire global economy to strictly renewable energies, the next generations will also need enough energy to run an immense atmospheric garbage-disposal project.

After Geoengineering gives brief mentions but no sustained discussion of this energy crunch.

One of the intriguing features of the book is the incorporation of short fictional sketches of lives and lifestyles in coming decades. These sketches are well drawn, offering vivid glimpses of characters dealing with climate instability and working in new carbon drawdown industries. The vignettes certainly help in putting human faces and feelings into what otherwise might remain abstract theories.

Yet there is no suggestion that restricted energy supplies will be a limiting factor. The people in the sketches still travel in motorized vehicles, check their computers for communications, run artificial intelligence programs to guide their work, and watch TV in their high-rise apartments. In these sketches, people have maintained recognizably first-world lifestyles powered by zero-emission energy technologies, while managing a carbon drawdown program on the same scale as today’s fossil fuel industry.

If you lean strongly towards optimism you may hope for that outcome – but how can anyone feel realistically confident in that outcome?

The lack of a serious grappling with this energy challenge is, in my mind, the major shortcoming in After Geoengineering. And big questions about energy supply will hang in the air not only around carbon sequestration, but also around solar geoengineering if humanity comes to that.

Shaving the peak

Solar geoengineering –  the intentional pumping of substances into the upper atmosphere into order to block a percentage of incoming sunlight to cool the earth – has also earned a bad name among climate activists. It is, of course, a dangerous idea – just as extreme as the practice of pumping billions of tonnes of extra carbon dioxide into the atmosphere to overheat the earth.

But Buck makes a good case – a convincing case, in my opinion – that in order to justifiably rule out solar geoengineering, we and our descendants will have to do a very good job at both eliminating carbon emissions and drawing down our current excess of carbon dioxide, fast.

Suppose we achieve something which seems far beyond the capabilities of our current political and economic leadership. Suppose we get global carbon emissions on a steep downward track, and suppose that the coming generation manages to transition to 100% renewable while also starting a massive carbon drawdown industry. That would be fabulous – and it still may not be enough.

As Buck points out, just as it has proven difficult to predict just how fast the earth system responds to a sustained increased in carbon dioxide levels, nobody really knows how quickly the earth system would respond to a carbon drawdown process. The upshot: even in an era where carbon dioxide levels are gradually dropping, it will be some time before long-term warming trends reverse. And during that interim a lot of disastrous things could happen.

Take the example of coral reefs. Reef ecosystems are already dying due to ocean acidification, and more frequent oceanic heat waves threaten to stress reefs beyond survival. Buck writes,

“Reefs protect coasts from storms; without them, waves reaching some Pacific islands would be twice as tall. Over 500 million people depend on reef ecosystems for food and livelihoods. Therefore, keeping these ecosystems functioning is a climate justice issue.” (AG, p 216)

In a scenario about as close to best-case as we could realistically expect, the global community might achieve dropping atmospheric carbon levels, but still need to buy time for reefs until temperatures in the air and in the ocean have dropped back to a safe level. This is the plausible scenario studied by people looking into a small-scale type of geoengineering – seeding the air above reefs with a salt-water mist that could, on a regional scale only, reflect back sunlight and offer interim protection to essential and vulnerable ecosystems.

One could say that this wouldn’t really be geoengineering, since it wouldn’t affect the whole globe – and certainly any program to affect the whole globe would involve many more dangerous uncertainties.

Yet due to our current and flagrantly negligent practice of global-heating-geoengineering, it is not hard to imagine a scenario this century where an intentional program of global-cooling-geoengineering may come to be a reasonable choice.

Buck takes us through the reasoning with the following diagram:

From After Geoengineering, page 219

If we rapidly cut carbon emissions to zero, and we also begin a vast program of carbon removal, there will still be a significant time lag before atmospheric carbon dioxide levels have dropped to a safe level and global temperatures have come back down. And in that interim, dangerous tipping points could be crossed.

To look at just one: the Antarctic ice sheets are anchored in place by ice shelves extending into the ocean. When warming ocean water has melted these ice shelves, a serious tipping point is reached. In the words of Harvard atmospheric scientist Peter Irvine,

“Because of the way the glaciers meet the ocean, when they start to retreat, they have kind of a runaway retreat. Again, very slow, like a couple of centuries. Five centuries. But once it starts, it’s not a temperature-driven thing; it’s a dynamic-driven thing … Once the ice shelf is sheared off or melted away, it’s not there to hold the ice sheet back and there’s this kind of dynamic response.” (AG, p 236)

The melting of these glaciers, of course, would flood the homes of billions of people, along with a huge proportion of the world’s agricultural land and industrial infrastructure.

So given the current course of history, it’s not at all far-fetched that the best option available in 50 years might be a temporary but concerted program of solar geoengineering. If this could “shave the peak” off a temperature overshoot, and thereby stop the Antarctic ice from crossing a tipping point, would that be a crazy idea? Or would it be a crazy idea not to do solar geoengineering?

These questions will not go away in our lifetimes. But if our generation and the next can end the fossil fuel frenzy, then just possibly the prospect of geoengineering can eventually be forgotten forever.

1 Greta Thunberg, “If world leaders choose to fail us, my generation will never forgive them”, address to United Nations, New York, September 23, 2019, as printed in The Guardian.
2 In the webinar “Towards a 20 GT Negative CO2 Emissions Industry”, sponsored by Security and Sustainability Forum, Sept 19, 2019.