The world will eventually return to a post-pandemic reality where climate change will once again dominate the national and global agenda. In his first Policy Speaking blog, Dale Eisler, Senior Policy Fellow at the Johnson Shoyama Graduate School of Public Policy at the University of Regina summarizes renowned professor and author Vaclav Smil's latest article 'What we need to know about the pace of decarbonisation.”

As Canada struggles with the daunting economic and social consequences of the COVID-19 pandemic, it is understandable if people are distracted from the challenge of climate change. But the overarching national goal of reducing emissions by 2030 and reaching net zero emissions by 2050 remains. Canada and the world will eventually return to a post-pandemic reality. When that happens, climate change is likely to once again dominate the national and global agenda and one powerful but little-known voice from Manitoba, will no doubt stand out.

Many people have never heard his name. But University of Manitoba professor Vaclav Smil has developed a cult-like following as an international authority on the history of energy transitions. The widely-respected Science Magazine calls him “the man who has quietly shaped how the world thinks about energy.” In the words of Bill Gates, who is deeply committed to addressing climate change, “there is no author whose books I look forward to more than Vaclav Smil.”

Smil is the author of 40 books, most recently “Energy and Civilization, A History” and “Growth, From Microorganisms to Megacities.” Gates calls “Energy and Civilization” a “masterpiece”.

The message Smil delivers is both blunt and provocative. Faced, as we are, with the existential challenge of climate change, he argues growth cannot continue at its current pace in many developed societies. In a September 2019 interview with The Guardian newspaper headlined “Vaclav Smil: Growth must end. Our economist friends don’t seem to realize that,” Smil talks about how the relative need for growth varies from region to region. “For example, Denmark has nothing in common with Nigeria. What you do in each place will be different. What we need in Nigeria is more food, more growth. In the Philippines we need a little more of it. And in Canada and Sweden, we need less of it… In some places we have to foster what economists call de-growth. In other places, we have to foster growth.”

Smil injects expectations and standards of living considerations into discussions about meeting the climate change challenge. In a 2019 paper entitledRealities vs. miraculously bending curves”, he notes that demand for what he cites as the four material pillars of modern civilization (steel, cement, ammonia and plastics) remains strong, and argues we lack non-carbon alternatives to produce these materials rapidly and affordably at the requisite scales.

“As a result, the world cannot expect any sudden, miraculous and rapid reversal of CO2 emissions, no instant bending of the curve so fancifully depicted in the latest IPCC report.” – Vaclav Smil

Steep, rapid decline in emissions required

IPCC 2018 (Intergovernmental Panel on Climate Change)

In a recent edition of Substantia, an International Journal of the History of Chemistry, Smil explores the challenge of decarbonization. He argues the proper recognition of “energetic, engineering and economic realities” means that decarbonization of global energy supply will be much more difficult and take much longer than is often assumed by uncritical proponents of “green” solutions. Smil puts the current debate over energy transition to a net zero economy by 2050 into the context of previous energy transitions. He notes we have been in a process of decarbonization for more than the last century as we moved from traditional biofuels, such as wood, to fossil fuels. But constant growth and consumption have brought us record CO2 levels, creating the climate change crisis.

Below is an adapted version of Dr. Smil’s recent article “What we need to know about the pace of decarbonization.”


Energy transitions have been among the key defining processes of human evolution. The first millennia-long transition was from the reliance on traditional biofuels such as wood, charcoal, crop residues and animate sources of energy derived from human and animal muscles, to increasingly common reliance on inanimate energy converters. They included water wheels, wind mills and better harnessed draft animals for fieldwork and transportation.

Transition to fossil fuels to produce heat, thermal electricity and kinetic energy began in England during the 16th century. It took hold in Europe and North America only after 1800, and in most of Asia only after 1950. This transition has been accompanied by increasing reliance on primary electricity, dominated by hydroelectricity since the 1880s, with nuclear generation contributing since the late 1950s. The transition from traditional biofuels to fossil fuels has resulted in gradual relative decarbonization, but also in enormous growth in absolute emissions of CO2.

This decarbonization from traditional biofuels to hydroelectricity and fossil fuels that dominate today is best traced by the increasing hydrogen-to-carbon ratios of major fuels. They rise from no more than 0.5 for wood and 1.0 for coal, to 1.8 for the lightest refined fuels and to 4.0 for methane, the dominant constituent of natural gas. The reverse order applies to CO2 emissions per unit of energy.

As the global energy transition progressed, coal consumption overtook the burning of traditional biofuels and was, in turn, surpassed by the combined mass of hydrocarbons (crude oils and natural gases). The rising share of primary electricity, much of it generated by hydro power, has further reduced the average carbon intensity of the world’s primary energy supply. But this relative decline has been accompanied by an almost uninterrupted growth of absolute CO2 emissions.

Growth of CO2 in the atmosphere

Combustion of fossil fuels contributed just eight million tonnes (Mt) of carbon in 1800, 534 Mt in 1900, 6.77 billion tonnes (Gt) in 2000 and 9.14 Gt in 2018. These emissions have been the principal reason for the rising atmospheric concentration of CO2, from 285 parts per million (ppm) in 1850 to 369.6 ppm in the year 2000 and to 408.5 ppm in 2018. In turn, these rising concentrations have been the principal reason for the gradual increase of average tropospheric temperature that has, so far, amounted to about 0.8 C. But that level would, in the absence of any remedial actions, surpass 2 C or even 3 C in a matter of decades and result in rapid anthropogenic global warming.

Past energy transitions were driven by a variety of factors. They ranged from the need for higher unit power and better conversion efficiency, to more affordable supply and reduced environmental impacts – for example natural gas is a much cleaner fuel than coal. In contrast to previous energy transitions, today’s quest for decarbonization is not primarily driven by resource shortages or technical imperatives. The reality is most existing conversions are highly efficient and also very reliable. The objective to decarbonize the economy has one dominant goal: limiting the extent of global warming.

The goal is to establish a new global energy system that would be devoid of any combustion of carbon-containing fuels. It would be a world with net-zero carbon emissions, where a limited amount of fossil fuel combustion would be negated by the removal and sequestration of the gas from the atmosphere resulting in no additional carbon releases.

Concerns about anthropogenic global warming have existed since the late 19th century. But they began to receive wider public attention during the 1980s, and particularly when the first United Nations Framework Convention on Climate Change was signed in 1992. It was followed by the Kyoto Protocol of 1997 and its latest global endeavor was the 2015 Paris Agreement, which included nationally determined contributions designed “to combat climate change and to accelerate and intensify the actions and investments needed for a sustainable low carbon future,” as stated by the United Nations Climate Change Convention of 2019.

Numerous meetings and assorted pledges aside, what has actually taken place since 1992?

The most important fact is that during those decades of rising concerns about global warming the world has been running towards fossil carbon, not moving away from it. Since 1992 absolute emissions of CO2 from fossil fuel combustion have declined significantly, by nearly 20% in the European Union, and have grown only marginally – in each case by about 5% – in the US and Japan. But these accomplishments have not set the world on the road to decarbonization as emissions have nearly tripled in Asia, largely because the Chinese combustion of fossil fuels has almost quadrupled. As a result, global emissions of CO2 increased by more than 60% since 1992, setting yet another record in 2018.

Historians of energy transitions are not surprised by this development. That’s because history shows that neither the dominant sources of primary energy, nor the common energy converters can be displaced rapidly and completely in short periods of time. The high degree of the global dependence on fossil carbon and the enormous scale of the fuel-dominated global energy system mean that the unfolding energy transition towards decarbonization will inevitably follow the progress of all previous large-scale primary energy shifts. In other words, it will be a gradual, prolonged affair.

At the turn of the 19th century, traditional biomass fuels supplied all but a tiny share of the world’s primary energy. A century later, their share was about 50%, and at the beginning of the 21st century still accounted for nearly 10%. This means that even after more than two centuries the world has not completed the shift from traditional biofuels to modern sources of primary energy. Coal’s share of global primary energy supply has been in retreat for generations as the reliance on hydrocarbons has grown, but the fuel still supplies nearly 30% of the total requirement. That is still more than natural gas, whose commercial extraction began about 150 years ago. In absolute terms, its output is more than eight times larger than it was in 1900 when the fuel dominated the global energy supply. While most economies began reducing their crude oil reliance after OPEC’s large price increases of the 1970s, it remains the dominant primary energy source, supplying almost 40% of the world’s total.

An energy transition that is unprecedented

To put this into perspective, the unfolding transition to non-carbon energies has to take place on unprecedented scales. Consider that annual extraction of fossil fuels includes about 7.7 Gt of coal, 4.4 Gt of crude oil and 3.7 trillion cubic metres of natural gas. Unlike all other previous shifts in primary energy use, decarbonization can achieve its goal only when it succeeds on a global scale. Even instant decarbonization in a major advanced economy makes little difference if GHG emissions from other sources and countries keep rising. The reality is that after three decades, the unfolding transition is still in its earliest stage and the relative shift has been minor. In 1990 fossil fuels supplied 91.3% of the world’s primary energy and by 2017 their share was still 90.4%.

Moreover, if the decarbonization of global electricity generation were to proceed at an unprecedented pace, only the availability of affordable, massive-scale electricity storage would make it possible to envisage a reliable system that could rely solely on intermittent renewable energies of solar radiation and wind. Even securing just three days’ worth of storage for a megacity of more than 10 million people that would be cut off from its intermittent renewable sources – which is a common occurrence during the monsoonal season in Asia with heavily overcast skies and high winds – would be prohibitively expensive by using today’s commercial batteries. Setting aside exaggerated media claims, a technological breakthrough meeting that requirement appears unlikely in the near future as pumped hydro storage, which was originally introduced during the 1890s, remains today the only way to store electricity at gigawatt scale. And even major advances toward large-scale electricity storage would not be enough to bring about rapid decarbonization of the global energy supply as electricity generation accounts for no more than 20% of total final energy consumption. As well, decarbonizing transportation, heating, agriculture and industrial production is considerably more difficult than installing new intermittent capacities, connecting them with major load centres and securing the required back-up supply.

India’s projected energy consumption

Electrification of passenger cars is in its earliest stage, with 5.4 million electric vehicles on the road by the end of 2018, still less than 0.2% of all vehicles registered worldwide. More than a century after they were first seen as the best road transportation choice, electric cars are finally ascendant. But even under the most optimistic circumstances it will take many decades to accomplish the transition from internal combustion engines. The International Energy Agency sees 160-200 million electric vehicles by 2030, BP expects 320 million by 2040 and my best forecast (based on a polynomial regression) is for 360 million in 2040. But by that time there might be about 2 billion vehicles on the road globally compared to about 1.25 billion today. Hence even 400 million electric cars would be just 20% of the total. Forecasting the future adoption of hydrogen-fuelled vehicles is even more uncertain, making it difficult to see how even the most likely combined progression of electric and hydrogen cars would completely eliminate internal combustion engines before 2040, or even soon after.

Given the energy density of today’s best commercial batteries, the electrification of trucking, shipping and flying is even more challenging. The key to understanding the fundamental difficulty is to compare the energy density of the best Li-ion batteries with the energy density of diesel fuels used in trucking and shipping. Today Li-ion batteries have energy density of up to 260 watt-hour per kilogram (wh/kg) and could reach up to 500 wh/kg in the future. The energy density of diesel and aviation kerosene is 12,600 wh/kg and 12,800 wh/kg. In other words, 50 times the energy density of our best commercial batteries. So shipping and flying present particularly insurmountable challenges as only high energy density fuels can power massive container ships and high-capacity airliners.

While air conditioning is powered by electricity, seasonal heating in cold parts of Eurasia and North America now relies overwhelmingly on natural gas delivered by large-diameter trunk lines and dense networks of smaller-diameter distribution lines serving more than a half billion customers. Obviously, replacing this fuel supply and abandoning this extensive infrastructure will not be achieved over a single generation.

And even more intractable challenges come with the decarbonization of industries producing what I call the four pillars of modern civilization: ammonia, cement, steels and plastics.

Another critical factor to consider is the enormous energy, food and material needs of emerging economies. China’s population of 1.39 billion will soon be surpassed by India, which has a per capita use about 25% that of China’s. According to the National Institute for Transforming India, the country’s total primary energy consumption is forecast to increase nearly fivefold by 2047, with coal remaining the dominant fuel.


In conclusion, the verdict – based on the history of past energy transitions, on the unprecedented scales of the unfolding shift, on the limits of alternative pathways, and on the enormous and immediate energy needs of billions of people in low-income countries – is clear. Designing hypothetical roadmaps outlining complete elimination of fossil carbon from the global energy supply by 2050 is nothing but an exercise in wishful thinking that ignores fundamental physical realities. And it is no less unrealistic to propose legislation, as has been done in the U.S. Congress, claiming that such a shift can be accomplished in the U.S. by 2030. Such claims are simply too extreme to be defended as aspirational. The complete decarbonization of the global energy supply will be an extremely challenging undertaking of an unprecedented scale and complexity that will not be accomplished – even in the case of sustained, dedicated and extraordinarily costly commitment – in a matter of a few decades.

By: Dale Eisler, Senior Policy Fellow, Johnson Shoyama Graduate School of Public Policy, University of Regina


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