How the World Really Works: The Science Behind How We Got Here and Where We're Going

by Vaclav Smil

At the opposite end of the voluntary risk spectrum are activities whose brief duration carries a high probability of death. None is riskier than base jumping from cliffs, towers, bridges, and buildings. The most reliable study of this “asking for it” madness looked at an 11-year period of jumping from the Kjerag Massif in Norway, where 1 in every 2,317 jumps (9 in total) resulted in death,[55] with an average exposure risk of 4 × 10-2 (0.04). For comparison, in skydiving a fatal accident used to take place roughly once every 100,000 jumps but the latest US data show one fatality for every 250,000 jumps. With a typical descent lasting five minutes the exposure risk is only about 5 × 10-5, still 50 times higher than just sitting in a chair for those five minutes—but it is only about 1/1,000 of the risk associated with base jumping.[56]

Numbers of all natural catastrophes recorded by Munich Re show expected year-to-year fluctuations but the upward trend has been unmistakable: a slow increase between 1950 and 1980, a doubling of annual frequency between 1980 and 2005, and about a 60 percent rise between 2005 and 2019.[65] Overall economic losses (reflecting exceptional burdens stemming from major disasters) show even greater annual fluctuations and an even steeper rising trend. When measured in constant 2019 monies, the pre-1990 record was about $100 billion, while 2011 set an all-time record of just over $350 billion and that total was nearly matched in 2017. Insured losses ranged mostly between 30 and 50 percent of total losses, with the 2017 record reaching nearly $150 billion.

supernova

A blast that would damage the Earth’s ozone layer must take place less than 50 light-years away, but all of our “nearby” stars that might possibly explode are much farther than this, and while a gamma-ray burst could affect Earth from as far as 10,000 light-years once every 15 million years, the closest such burst on record was 1.3 billion light-years away.[70]

Perhaps the best example of a natural risk that would not directly kill anybody, but that would cause enormous planet-wide disruptions resulting in a large number of indirect casualties, is the possibility of a catastrophic geomagnetic storm caused by a coronal mass ejection.[73]

Coronal ejections begin with the twisting and reconfiguration of the magnetic field in the layer’s lower part; they produce solar flares and can travel (expanding as they advance) at speeds as slow as less than 250 km/s (arriving at the Earth in nearly seven days) and as fast as almost 3,000 km/s (reaching the Earth in as little as 15 hours).

the lessons we derive in the aftermath of major catastrophic events are decidedly not rational. We exaggerate the probability of their recurrence, and we resent any reminders that (setting the shock aside) their actual human and economic impact has been comparable to the consequences of many risks whose cumulative toll does not raise any extraordinary concerns. As a result, fear of another spectacular terrorist attack led the US to take extraordinary steps to prevent it. These included multitrillion-dollar wars in Afghanistan and Iraq, fulfilling Osama bin Laden’s wish to draw the country into stunningly asymmetrical conflicts that would erode its strength in the long run.[99] Public reaction to risks is guided more by a dread of what is unfamiliar, unknown, or poorly understood than by any comparative appraisal of actual consequences. When these strong emotional reactions are involved, people focus excessively on the possibility of a dreaded outcome (death by a terrorist attack or by a viral pandemic) rather than trying to keep in mind the probability of such an outcome taking place.[100] Terrorists have always exploited this reality, forcing governments to take extraordinarily costly steps to prevent further attacks while repeatedly neglecting to take measures that could have saved more lives at a much lower cost per averted fatality.

critical biospheric boundaries includes nine categories: climate change (now interchangeably, albeit inaccurately, called simply global warming), ocean acidification (endangering marine organisms that build structures of calcium carbonate), depletion of stratospheric ozone (shielding the Earth from excessive ultraviolet radiation and threatened by releases of chlorofluorocarbons), atmospheric aerosols (pollutants reducing visibility and causing lung impairment), interference in nitrogen and phosphorus cycles (above all, the release of these nutrients into fresh and coastal waters), freshwater use (excessive withdrawals of underground, stream, and lake waters), land use changes (due to deforestation, farming, and urban and industrial expansion), biodiversity loss, and various forms of chemical pollution.

Strawman. There’s no serious policy debates that we risk a loss of oxygen. Why not address the increase in greenhouse gasses?

The combined area devoted to food production is now more than twice as large as it was a century ago, but in all affluent economies the land under cultivation has either stabilized or has slightly decreased, while the overall global growth of new farmland has slowed down considerably.[23]

For centuries before 1800, CO2 levels fluctuated narrowly at close to 270 parts per million (ppm)—that is, 0.027 percent by volume. By 1900 they rose slightly to 290 ppm, a century later they were nearly 375 ppm, and in the summer of 2020 they rose above 420 ppm, more than a 50 percent increase above the late 18th-century level.[37] Preindustrial methane levels were three orders of magnitude lower—less than 800 parts per billion (ppb)—but they have more than doubled, to nearly 1,900 ppb by 2020, while nitrous oxide concentrations rose from about 270 ppb to more than 300 ppb.[38]

CO2 (mostly emitted from fossil fuel combustion, with deforestation being another major source) accounts for about 75 percent of the anthropogenic warming effect, CH4 for about 15 percent, and the rest is mostly N2O.[40]

Nighttime temperatures are increasing faster than the daytime averages mainly because the boundary layer (the atmosphere just above the ground) is very thin—mere hundreds of meters—during the night, compared to several kilometers during the day, and hence it is more sensitive to warming.[45]

In 1957, three decades before the sudden surge of interest in global warming, Roger Revelle, an American oceanographer, and Hans Suess, a physical chemist, appraised the process of mass-scale fossil fuel combustion in its correct evolutionary terms: “Thus human beings are now carrying out a large scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future. Within a few centuries we are returning to the atmosphere and oceans the concentrated organic carbon stored in sedimentary rocks over hundreds of millions of years.”[47] I cannot imagine what other phrasing could have better conveyed the unprecedented nature of this new reality.

The IPCC’s fifth assessment report, published more than a century after Arrhenius offered the value of 4°C, concluded that it is extremely unlikely that the sensitivity is less than 1°C and very unlikely that it is above 6°C, with the likely range between 1.5°C and 4.5°C, the same as the 1979 National Research Council report.[50] And in 2019, a comprehensive assessment of Earth’s climate sensitivity (using multiple lines of evidence) narrowed the most likely response to between 2.6°C and 3.9°C.[51] This means that climate sensitivity is extremely unlikely to be so low that it could prevent substantial warming (in excess of 2°C) by the time the atmospheric CO2 concentration rises to about 560 ppm, twice the preindustrial level.

global climate change is an extraordinarily complex development whose eventual outcome depends on far-from-perfectly understood interactions of many natural and anthropogenic processes. As a result, we will need, for decades to come, more observations, more studies, and far better climate models in order to get more accurate appraisals of long-term trends and of the most likely outcomes.

During the 2010s, SUVs became the second-highest cause of rising CO2 emissions, behind electricity generation and ahead of heavy industry, trucking, and aviation. If their mass public embrace continues, they have the potential to offset any carbon savings from the more than 100 million electric vehicles that might be on the road by 2040!

what have we done to avert, or to reverse, the unfolding environmental change in the three decades since global warming became a dominant topic of modern discourse? The data are clear: between 1989 and 2019 we increased global anthropogenic greenhouse gas emissions by about 65 percent. Even when we deconstruct this global mean, we see that affluent countries like the US, Canada, Japan, Australia, and those in the EU, whose per capita energy use was very high three decades ago, did reduce their emissions, but only by about 4 percent, while Indian emissions quadrupled and Chinese emissions rose 4.5 times.[77]

In 2015, when about 50,000 people flew to Paris in order to attend yet another conference of the parties at which they were to strike, we were assured, a “landmark”—and also “ambitious” and “unprecedented”—agreement, and yet the Paris accord did not (could not) codify any specific reduction targets by the world’s largest emitters, and it would, even if all voluntary non-binding pledges were honored (something utterly improbable), result in a 50 percent increase of emissions by 2050.[80] Some landmark.

expansion of China’s coal extraction (it more than tripled between 1995 and 2019, to nearly as much as the rest of the world combined)

in 2017 an assessment that considered the capacity of the oceans to absorb carbon, the planet’s energy imbalances, and the behavior of fine particles in the atmosphere concluded that the committed global warming (arising from past emissions and becoming a reality even if all new emissions ceased instantly) had already added up to 1.3°C and hence it would require only an additional 15 years of new emissions to surpass 1.5°C.[83] The latest analysis of these combined effects concluded that we are already committed to global warming of 2.3°C.[84]

All of these models should be seen mainly as heuristic exercises, as bases for thinking about options and approaches, never to be mistaken for prescient descriptions of our future. I wish this admonition would be as obvious, as trivial, and as superfluous as it seems!

In reality, most of these forecasts are no better than simple guesses: any number for 2050 obtained by a computer model primed with dubious assumptions—or, even worse, by a politically expedient decision—has a very brief shelf life. My advice: if you would like a better understanding of what the future may look like, avoid these new-age dated prophecies entirely, or use them primarily as evidence of prevailing expectations and biases.

hundreds of millions of stunted children, mostly in Africa, need to drink more milk and eat more meat, and that protein can come only from substantially increasing the amount of nitrogen they use in cropping.

before 1920, we had to devote a quarter of American farmland to feed crops for horses and mules),

Even though the supply of new renewables (wind, solar, new biofuels) rose impressively, about 50-fold, during the first 20 years of the 21st century, the world’s dependence on fossil carbon declined only marginally, from 87 percent to 85 percent of the total supply, and most of that small relative decline was attributable to expanded hydroelectricity generation, an old form of renewable energy.[35]

the fundamentals of our lives will not change drastically in the coming 20–30 years, despite the near-constant flood of claims about superior innovations ranging from solar cells to lithium-ion batteries, from the 3-D printing of everything (from microparts to entire houses) to bacteria able to synthesize gasoline. Steel, cement, ammonia, and plastics will endure as the four material pillars of civilization; a major share of the world’s transportation will be still energized by refined liquid fuels (automotive gasoline and diesel, aviation kerosene, and diesel and fuel oil for shipping); grain fields will be cultivated by tractors pulling plows, harrows, seeders, and fertilizer applicators and harvested by combines spilling the grains into trucks. High-rise apartments will not be printed on site by gargantuan machines,

the risk will be significantly higher because the combination of natural aging and prolongation of life will greatly increase the share of people over 65 years of age. The UN projects that share rising by about 70 percent by 2050, and in better-off countries one person in four will be older than that.[52] How will we cope in 2050 with a pandemic that might be more infectious than COVID-19, when in some countries a third of the population is in the most vulnerable category?

The future is a replay of the past—a combination of admirable advances and (un)avoidable setbacks. But there is something new as we look ahead, that unmistakably increasing (albeit not unanimous) conviction that, of all the risks we face, global climate change is the one that needs to be tackled most urgently and effectively.

Dealing with this challenge will, for the first time in history, require a truly global, as well as a very substantial and prolonged, commitment. To conclude that we will be able to achieve decarbonization anytime soon, effectively and on the required scales, runs against all past evidence.

Recall that the much-praised Paris accord had no specific emission-reduction targets for the world’s largest emitters, and that its non-binding pledges would not mitigate anything—they would result in 50 percent higher emissions by 2050!