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

Author:Vaclav Smil [Smil, Vaclav]
Language: eng
Format: epub
Publisher: Penguin Publishing Group
Published: 2022-05-10T00:00:00+00:00

6. Understanding the Environment

The Only Biosphere We Have

This chapter’s subtitle is deliberately preventive. I refuse to consider any near-term possibility of leaving the Earth and setting up a civilization on another planet. I do this because, in this post-factual world, musings about soon finding a new celestial abode—most notably, the terraforming of Mars[1]—have been presented as possible options to deal decisively with the problems of the third planet orbiting the Sun. This is yet another favorite topic of the sci-fi genre that will remain confined to its stories: even if we had inexpensive means of interplanetary transport and somehow mastered the construction of Martian bases, we could not create a suitable atmosphere—the processing of Martian polar caps, minerals, and soil would yield only about 7 percent of all the CO2 that would be needed in order to warm the planet and make its prolonged colonization possible.[2]

Of course, the true believers can call on another sci-fi trick that could enable the colonization of Mars: creating radically genetically re-engineered humans, new super-organisms endowed with qualities of terrestrial tardigrades, tiny eight-legged invertebrates living on grass and in wet ditches. Such organisms would be able to cope not only with the thin atmosphere (its pressure is less than 1 percent of the terrestrial value) but also with the high radiation received by the poorly shielded red planet.[3]

Returning to the real world, if our species is to survive, never mind to flourish, for at least as long as high civilizations have been around (that is, for another 5,000 or so years), then we will have to make sure that our continuing interventions do not imperil the long-term habitability of the planet—or, as modern parlance has it, that we do not transgress safe planetary boundaries.[4]

The list of these 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.

Providing systematic reviews of all of these concerns—and setting them in their appropriate historical and environmental perspectives—is a task for a major book, not for a single chapter (unless it consisted of superficial summaries). Instead, I have decided to give this chapter a decidedly utilitarian tilt and focus on just a few key existential parameters, starting with the environmental circumstances of three irreplaceable existential requirements—breathing, drinking, and eating. Provision of these three preconditions of our existence depends on natural goods and services: on the oxygenated atmosphere and its incessant circulation; on water and its global cycle; and on soils, photosynthesis, biodiversity, and flows of plant nutrients. In turn, their provision affects natural goods and services.

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