Under a White Sky: The Nature of the Future

Assisted evolution is the practice of accelerating the process of evolution, which usually takes millennia, to meet human timescales. In the book, we follow assisted evolution in the context of corals. Researchers are stress-testing corals to see which can survive harsh environments. Those that do are cross-bred with other resilient corals, and their offspring subjected to still more stress. The idea is to seed reefs with the resulting corals, which can hopefully withstand warmer and more acidic oceans.

If Asian carp were to reach the Great Lakes, they could have devastating effects on local ecosystems. To keep carp from reaching the Great Lakes, engineers have erected electric barriers on the Chicago Sanitary and Ship Canal. However, electrocution is not a fail-safe, so fishermen set out gillnets upriver to haul in huge quantities of carp through barrier defense.

BECCS, or bioenergy with carbon capture and storage, is a form of negative emissions technology that proposes to plant trees, or some other crop, and then burn those trees to create electricity; the resulting emissions would be pulled from the air and injected underground. This idea is part of a host of options that propose using natural systems to pull carbon dioxide from the air; other alternatives include planting a trillion trees and burying them in trenches to prevent decay (and thus slow emissions), or dropping vegetation into the deepest parts of the ocean, where such vegetation would not rot.

Biocontrol is the practice of using one species to control the spread of another. It became particularly popular following the publication of Rachel Carson’s Silent Spring, in which Carson identified serious concerns with pesticides and other chemicals and suggested using the power of the natural world instead. But the use of biocontrol had serious unintended consequences, including the spread of Asian carp in the US (they were imported to control another invasive species, but quickly escaped from their original introduction site) and the cane toad in Australia (it was imported to protect sugar cane and quickly spread across the continent).

A crevasse is the phenomenon whereby the Mississippi bursts through its banks. Crevasses have historically been highly destructive. As a result of that threat, the Army Corps of Engineers strengthened flood defenses on the Mississippi, but in recent years, people have realized that this has negative consequences: Blocking the movement of the river—and therefore of sediment—causes land loss and worsens coastal erosion. Recently, attempts have been made to create manmade crevasses to restore the flow of sediment.

CRISPR is a DNA-manipulation technology that can be used in gene drives, or process of quickly introducing new genes to a population. With CRISPR, a user can either disable a section of DNA or replace it with a different one, creating organisms like ants with no sense of smell, coffee beans without caffeine and cane toads that aren’t poisonous. CRISPR can also alter regular patterns of genetic inheritance, so that a given gene is always handed down, even if that gene is detrimental to an organism’s survival (such as a gene that prevents eggs from being fertilized). Because an entire animal population could be wiped out, this technology presents ethical concerns.

Taking carbon dioxide emissions out of the air is known as “negating” them. Many negative emissions techniques have been proposed, including pulling carbon dioxide from the air and injecting it into basalt rock deep underground, and planting a trillion trees to absorb carbon dioxide while they grow. Negative emissions technologies are costly and difficult to scale up, but they’re also a way of addressing what may otherwise be an insurmountable challenge – keeping global temperature rise below 2 degrees Celsius, and ideally below 1.5.

Kolbert uses this term to refer to species that are entirely dependent on human beings for their survival, after having been put in a position of precarity by humans in the first instance. This includes the Devils Hole pupfish: Humans degraded their ecosystem in the 20th century; now only human support maintains their breeding habitat, food, and an artificial replica of their environment to sustain a reserve population of the species. Thousands of such species have human support in the form of managed burns, guided migration, artificial insemination, and other interventions ensuring survival despite human modifications of their environment.

Solar geoengineering is the practice of seeding particles into the stratosphere—a layer of the earth’s atmosphere—to prevent the sun’s rays from reaching the Earth. The practice draws inspiration from volcanic eruptions, which can change weather patterns as emissions from an eruption block the sun. Solar geoengineering proposes to replicate this process to prevent catastrophic climate change, using reflective particles such as diamonds or calcium carbonate. While such a solution would be relatively easy and fast, it could also change weather patterns for the worse in some parts of the world and may sap some of the urgency from other measures, such as ending the use of fossil fuels.