“Low probability, if not impossibility” of reaching net-zero emissions by 2050: Vaclav Smil

Guest Contributor
March 27, 2024

Note from Research Money’s Managing Editor: This is a condensed version of a new essay by globally renowned energy expert Vaclav Smil that was first published in J.P. Morgan’s 14th Annual Energy Paper. The choice of excerpts to include from Smil’s full essay, “Halfway Between Kyoto and 2050: Zero Carbon is a Highly Unlikely Outcome,” in this condensed version was Research Money’s. No content was changed; only minor editing was done for style, such as shorter paragraphs. Smil, who turned 80 last year, served for many years as technical advisor for J.P. Morgan’s annual energy paper.

By Vaclav Smil

Vaclav Smil is Distinguished Professor Emeritus at the University of Manitoba. He does interdisciplinary research in the fields of energy, environmental and population change, food production, history of technical innovation, risk assessment and public policy. He is the author of 47 books (including: Energy Transitions; How the World Really Works; Invention and Innovation; Energy and Civilization: A History; Energy in World History; Size: How it Explains the Word) and more than 500 papers on these topics.

 Clearing of forests, large-scale cropping and animal husbandry have been with us throughout recorded history but the rising combustion of fossil fuels has been by far the greatest contributor of carbon dioxide during the past two centuries, followed by methane (from rice fields, landfills, cattle, and natural gas production), and nitrous oxide (mostly from nitrogenous fertilizers).

Realization that these trace gases could affect climate is more than 150 years old. There has been an exponential rise of attention paid to global climate change. Much has been learned, much remains uncertain but basic facts are indisputable. Ice core analyses show CO2 levels [in the atmosphere] close to 270 parts per million (ppm) by volume during the preindustrial era; in 1958 when Mauna Loa monitoring began they reached 313 ppm; by the year 2000 they were 370 ppm and by the end of 2023 they reached 420 ppm, more than 50 per cent above the late 18th-century level.

This rise, together with contributions by methane and nitrous oxide, has translated to about 1⁰C of global warming compared to the 19th-century mean. All continents have been affected, recent decadal warming gains have been steadily rising and the eight years between 2015 and 2022 were the warmest years on record.

“Low probability, if not impossibility” of achieving net zero by 2050

There is low probability, if not impossibility, of energizing the world’s economy without any fossil fuels by 2050. The goal of reaching net-zero global anthropogenic carbon dioxide emissions is to be achieved by an energy transition whose speed, scale, and modalities (technical, economic, social, and political) would be historically unprecedented.

What is particularly clear is that (in the absence of an unprecedented and prolonged global economic downturn) the world will remain far from reducing its energy-related CO2 emissions by 45 per cent from the 2010 level by 2030: for that we would have to cut emissions by nearly 16 billion tons between 2023 and 2030 – or eliminate nearly as much fossil carbon as the combined emissions of the two largest energy consumers, China and the U.S. The combination of scale and speed is the greatest factor making the unfolding transition so taxing.

In 2022 the world produced nearly 8.2 billion tons of coal, almost 4.5 billion tons of crude oil, and 2.8 billion tons of natural gas, all extracted very efficiently and mostly in a highly concentrated manner from large mines and from enormous hydrocarbon fields on every continent.

In terms of final energy uses and specific energy converters, the unfolding transition would have to:

  • replace more than 4 terawatts of electricity-generating capacity now installed in large coal- and gas-fired stations by converting to non-carbon sources.
  • substitute nearly 1.5 billion combustion (gasoline and diesel) engines in road and off-road vehicles.
  • convert all agricultural and crop processing machinery (including about 50 million tractors and more than 100 million irrigation pumps) to electric drive or to non-fossil fuels.
  • find new sources of heat, hot air, and hot water used in a wide variety of industrial processes (from iron smelting and cement and glass making to chemical syntheses and food preservation) that now consume close to 30 per cent of all final uses of fossil fuels.
  • replace more than half a billion natural gas furnaces now heating houses and industrial, institutional, and commercial places with heat pumps or other sources of heat.
  • find new ways to power nearly 120,000 merchant fleet vessels (bulk carriers of ores, cement, fertilizers, wood and grain, and container ships, the largest one with capacities of some 24,000 units, now running mostly on heavy fuel oil and diesel fuel) and nearly 25,000 active jetliners that form the foundation of global long-distance transportation (fueled by kerosene).

On the face of it, and even without performing any informed technical and economic analyses, this seems to be an impossible task given that:

  • we have only a single generation (about 25 years) to do it.
  • we have not even reached the peak of global consumption of fossil carbon.
  • the peak will not be followed by precipitous declines.
  • we still have not deployed any zero-carbon large-scale commercial processes to produce essential materials.
  • the electrification has, at the end of 2022, converted only about two per cent of passenger vehicles (more than 26 million) to different varieties of battery-powered cars and that decarbonization is yet to affect heavy road transport, shipping, and flying.

[According to the International Energy Agency’s World Energy Outlook], by 2050 even coal consumption, after an unprecedented projected decline, would still be as high as it was at the beginning of the 21st century. Both crude oil and natural gas consumption (yet to peak) would be nearly as high (more than 95 per cent) as in 2030; and a steady decline would still leave fossil fuel consumption at about 85 per cent of the current level.

In mass terms, we will never run out of fossil fuels: enormous quantities of coal and hydrocarbons will remain in the ground after we end their use because it would be too expensive to extract them. Although the world of the early 2020s is in no imminent danger of running out of fossil fuels, in the long run they would have to be replaced even in the absence of any connections to global warming.

Their conversions made the modern civilization possible, but their production, processing and transportation are often environmentally disruptive, with impacts ranging from land dereliction to water pollution; their combustion generates not only CO2 but also such pollutants as carbon monoxide, nitrogen (NO, NO2) and sulphur (SO2 and SO3) oxides and particulate matter; their highly uneven distribution contributes to worldwide economic inequalities, and the quest for secure fossil fuel supplies has led to many detrimental policies and contributed to recurrent conflicts.

Global energy transitions take decades

The current energy networks are complex, their establishment and operation require constant maintenance and upgrading, and their costs are considerable, yet they are only one of many parts that make up the vastly more complex global energy system.

That is why global energy transitions are complicated, multifaceted, protracted, and in their details rather unpredictable. They require system changes that involve mass-scale development, adoption, and massive scaling-up of new techniques (be they large-scale “green” hydrogen electrolysis or extensive multiplication of small modular fission reactors). They also require the construction of new extraction, processing, and distribution networks (to produce large quantities of basic materials, metals, synthetic compounds and automated controls). All of these changes require decades of steady, high-level investments and political commitments in order to yield major economic and social changes.

The unfolding energy transition requires not just very large numbers of new wind turbines and photovoltaic panels to generate “green” electricity. Renewable generation also needs expanded high-voltage transmission lines (overhead wires and undersea cables from offshore wind sites) to bring the electricity from the windiest and sunniest places to often distant cities and industrial areas.

As the new energy transition ramps up it will also need capacious electricity storage, such as batteries (or other mechanical, thermal, or chemical arrangements) large enough to cope with the intermittency of wind and solar radiation; the need will become imperative if these sources become dominant generators of electricity and if they are not complemented, as they are today, by base-load nuclear or fossil fueled generation or by near-instant deployment of gas turbines.

Moreover, there are many final energy conversions (ranging from heavy ocean shipping and long-distance commercial aviation to chemical industry dependent on fossil carbon feedstocks) that cannot be readily electrified. Further, we would need substantial quantities of solid and liquid fossil carbon even in the zero-carbon world for paving (asphalt) and for industrial and commercial lubricants.

Producing what I have called the four pillars of modern civilization – cement, primary iron, plastics, and ammonia – now depends on fossil fuels, and replacing them with alternatives will require the development of new mass-scale industries and distribution networks ranging from green hydrogen (made by electrolysis of water by green electricity) and ethanol to new synthetic fuels.

The promise of low-cost nuclear generation remains just that: by 2027 advanced nuclear generation is still expected to cost at least twice as much as combined cycle gas turbine [technology], unsubsidized electric cars remain more expensive than comparable gasoline-powered vehicles, and the cost of green hydrogen, now in the earliest stages of development, remains uncertain.

Despite decades of promises that the arrival of large numbers of small modular reactors (SMRs, up to 300 MW) was imminent, and that they would resurrect stagnating electricity generation by nuclear fission, and despite some 80 different designs, in 2023 not a single SMR was operating anywhere in the West. China has only a single test prototype. Similarly, proponents of geothermal generation stress its enormous potential, but practical advances have been slow there, too.

The unfolding transition thus relies on techniques that are not (as yet) compellingly and across-the-board cheaper, more reliable, and more than the conversion they are replacing.  Moreover, some of them (above all, new reactors and mass-scale electricity storage) will require a great deal of further expensive development.

No worldwide decarbonization has occurred

Contrary to common impressions, there has been no absolute worldwide decarbonization. In fact, the very opposite is the case. The world has become much more reliant on fossil carbon (even as its relative share has declined a bit). We are now halfway between 1997 (27 years ago) when delegates of nearly 200 nations met in Kyoto to agree on commitments to limit the emissions of greenhouse gases, and 2050; the world has 27 years left to achieve the goal of decarbonizing the global energy system, a momentous divide judging by the progress so far, or the lack of it.

The numbers are clear. All we have managed to do halfway through the intended grand global energy transition is a small relative decline in the share of fossil fuel in the world’s primary energy consumption – from nearly 86 per cent in 1997 to about 82 per cent in 2022. But this marginal relative retreat has been accompanied by a massive absolute increase in fossil fuel combustion: in 2022 the world consumed nearly 55 per cent more energy locked in fossil carbon than it did in 1997.

The conclusion is unequivocal: by 2023, after a quarter century of targeted energy transition, there has been no absolute global decarbonization of energy supply. Just the opposite. In that quarter century, the world has substantially increased its dependence on fossil carbon.

After cutting our relative dependence on fossil fuels by just 4 percent during the first half of the prescribed post-Kyoto period, even if there was no further increase in CO2 emissions we would have to cut it by 82 per cent by 2050. In absolute terms eliminating the generation of carbon from fossil fuel combustion would mean cutting energy-related emissions by an average of 1.45 billion tons a year (compared to the average annual rise in emissions of nearly half a billion tons since 1995). That would be like eliminating the equivalent of two years of Saudi emissions, or nearly half of India’s 2022 total – every year.

Another revealing way of viewing the daunting magnitude of this challenge is to look at the cuts that would have to be made by G20 economies to meet the interim 2030 goals: for nearly all major economies, it would generally mean halving the 2020 emissions, with cuts of 45 per cent for Canada and 46 per cent for Saudi Arabia, to 55 per cent for the EU, 56 per cent for the U.S., and 63 per cent for China. Only an unprecedented economic collapse could bring such cuts during the next seven years.

Costs of energy transition will be much higher than expected

Nobody can offer a reliable estimate of the eventual cost of a worldwide energy transition by 2050 though a recent (and almost certainly highly conservative) total suggested by McKinsey’s Global Institute makes it clear that comparing this effort to any former dedicated government-funded projects is another serious category mistake.

Their estimate of $275 trillion between 2021 and 2050 prorates to $9.2 trillion a year. Compared to the 2022 global GDP of $101 trillion, this implies an annual expenditure on the order of 10 per cent of the total worldwide economic product for three decades, rather than 0.2 or 0.3 per cent for a few years,

In reality, the real burden would be far higher for two reasons. First, it cannot be expected that low-income countries could sustain such a diversion of their limited resources and hence this global endeavour could not succeed unless the world’s high-income nations annually spend sums equal to 15 to 20 per cent of their GDP.

More importantly, this ultimate global transformation project would face enormous cost overruns. As the world’s most comprehensive study of cost overruns (more than 16,000 projects in 16 countries and in 20 categories, from airports to nuclear stations) shows, 91.5 per cent of projects worth more than $1 billion have run over the initial estimate, with the mean overrun being 62 per cent.

Applying a 60 per cent correction would raise McKinsey’s estimate of the cost of global decarbonization to $440 trillion, or nearly $15 trillion a year for three decades, requiring affluent economies to spend 20 to 25 per cent of their annual GDP on the transition. Only once in history did the U.S. (and Russia) spend higher shares of their annual economic product, and they did so for less than five years when they needed to win World War II. Is any country seriously contemplating similar, but now decades-long, commitments?

Given the fact that we have yet to reach the global carbon emission peak (or a plateau) and considering the necessarily gradual progress of several key technical solutions for decarbonization (from large-scale electricity storage to mass-scale hydrogen use), we cannot expect the world economy to become carbon-free by 2050. The goal may be desirable, but it remains unrealistic.

Belief in near-miraculous tomorrows never goes away. Even now we can read declarations claiming that the world can rely solely on wind and [solar photovoltaic] by 2030. And then there are repeated claims that all energy needs (from airplanes to steel smelting) can be supplied by cheap green hydrogen or by affordable nuclear fusion. What does this all accomplish besides filling print and screens with unrealizable claims?

Instead, we should devote our efforts to charting realistic futures that consider our technical capabilities, our material supplies, our economic possibilities, and our social necessities – and then devise practical ways to achieve them. We can always strive to surpass them – a far better goal than setting ourselves up for repeated failures by clinging to unrealistic targets and impractical visions.

Failing to reach an unrealistic goal of complete global decarbonization by 2050 means failing to limit average global warming to 1.5ºC. How much higher the temperature might rise will not depend only on our continued efforts to decarbonize the global energy supply but also on our success in limiting CO2 and other greenhouse gases generated by agriculture, animal husbandry, deforestation, land use changes, and waste disposal. After all, those contributions account for at least a quarter of global anthropogenic emissions but, so far, we have been almost exclusively focused on CO2 from fossil fuel combustion.

No natural laws bar us from making the enormous investments needed to sustain such massive annual shifts: we could resort to an unprecedented, decades-long, and civilization-wide existential mobilization of constructive and transformative efforts or, conversely, we could deliberately reduce our energy use by lowering our standard of living and keeping it low to make it easier to displace all fossil carbon.

In the absence of these two radical choices, we should not ignore the experience of the past grand energy transition (from traditional biomass energies to fossil fuels) and we should not underestimate the concatenation of challenges presented by practical engineering, material, organizational, social, political, and environmental requirements of the unfolding transition to a fossil carbon-free world that have been partially reviewed in this essay. When we do assess these challenges realistically, we must conclude that the world free of fossil carbon by 2050 is highly unlikely.


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