At a news conference in mid-August of last year, California’s governor, Gavin Newsom, announced that there were 367 “known” wildfires burning in the state. “I say ‘known’ fires,” Newsom said, “but the prospect of that number going up is very real.” A couple of days later the number did, in fact, increase, to 560. A few weeks after that, many of the blazes were still burning, and one—the Doe fire, north of Santa Rosa—had grown into the largest conflagration in California history. The smoke from the state was so bad that it veiled the sun in New England. By the time most of California’s flames had been put out in late November, at least 31 people had been killed and tens of thousands evacuated.
Even as more than 15,000 firefighters were battling the California wildfires, Hurricane Laura was bearing down on Louisiana. As it passed over the Gulf of Mexico, it strengthened at a near-record rate. In just 24 hours it zoomed from a Category 1 to a Category 4 storm. By the time it hit Cameron Parish, early in the morning of August 27, it was the fifth fiercest hurricane to make landfall in U.S. history. The storm caused at least 16 U.S. deaths and up to $12 billion in damages.
Twenty years ago, crises like the Doe fire and Hurricane Laura could have been described as “natural disasters.” Thanks to climate change, this is no longer the case. Right around the time of Newsom’s press conference, the mercury in Death Valley hit 130°F, the highest temperature ever reliably recorded on Earth. A hotter, drier California is much more likely to burst into flames. The Gulf too is heating up, with dangerous consequences. Hurricanes draw their energy from the warmth of the surface waters and so are becoming stronger and more apt to intensify. I’ve been reporting on climate change for almost two decades, and I’ve come to think that we need a new term to describe these events. Perhaps we should call them “man-made natural disasters.”
People now play such a dominant role on the planet, it’s said we live in a new geological epoch: the Anthropocene. By cutting down forests and digging mines and building cities, we’ve transformed half of the ice-free land on Earth. (Indirectly, we’ve altered half of what remains.) With our fertilizer plants, we fix more nitrogen than all terrestrial ecosystems combined; with our plows and bulldozers, we move around more earth than all the world’s rivers and streams. In terms of biomass, the numbers are staggering. People now outweigh wild mammals by a ratio of more than 8 to 1. Add in our domesticated animals (mostly cows and pigs), and the ratio’s almost 23 to 1. In the Anthropocene, all sorts of catastrophes straddle the line between man and nature. Many earthquakes, for example, are now triggered by human activity, in particular fracking. An unusually strong human-induced quake that shook Pawnee, Oklahoma, a few years ago was felt all the way to Des Moines, Iowa.
And then there’s COVID-19.
The virus that causes COVID seems to have originated in horseshoe bats. It appears to have made the leap to people near the city of Wuhan, China, either directly or through an intermediate species that has yet to be identified. Pathogens have, presumably, been jumping between animals and humans for as long as both have been around. But for most of human history, such “spillover events” were limited in their impact. Infected populations didn’t move very far or very fast. With jet travel, a virus can now make it halfway around the world between evening newscasts. Within a month of the first confirmed cases in central China, COVID had reached at least 26 other countries. Soon it was just about everywhere, even such remote places as the Falkland Islands and the Kamchatka Peninsula.
Just as with their predecessors, it’s hard to predict when or where man-made natural disasters will strike. Still, the trend lines are clear. As people increasingly destroy other animals’ habitats and move species around the world, outbreaks of novel diseases will become more common. Author (and frequent National Geographic contributor) David Quammen has put it this way: “We disrupt ecosystems, and we shake viruses loose from their natural hosts. When that happens, they need a new host.” Often, that new host is going to be us. (Quammen wrote about how viruses shape our world for the February issue of the magazine.)
Meanwhile, as the climate continues to warm, conflagrations will grow even larger and storms more damaging. A recent study showed that in California, the frequency of dangerous “fire weather” days has more than doubled over the past four decades. By the end of the century, it could double again. Ten or 20 years from now, last year’s record-breaking fires and floods will almost certainly have been overtaken by new record breakers. As Andrew Dessler, a professor of atmospheric sciences at Texas A&M University, observed last fall, “If you don’t like all of the climate disasters happening in 2020, I have some bad news for you about the rest of your life.”
What’s to be done? According to one school of thought, the best way to deal with human intervention in the natural world is to intervene better. Old technologies got us into this situation; new ones will get us out. Advocates of this view note the extraordinary advances that are being made all the time, in fields ranging from computing to genetics to material science. To make it easier to find treatments for COVID-19, Chinese researchers genetically altered mice to possess the same virus receptors as humans. The scientists used a technique known as CRISPR, which over the past few years has revolutionized gene editing. To combat climate change, engineers have built machines that suck carbon dioxide out of the air. Today the numbers are limited, but perhaps one day they’ll be as common as iPhones.
Alternatively, it’s been proposed that climate change could be counteracted by blocking some of the sun’s incoming rays. Researchers are working on technologies to brighten clouds, which would bounce more sunlight out to space. Another technique, known as “solar geoengineering,” would spread reflective particles in the stratosphere, providing the entire planet with a kind of sunshade.
“Ironically, such engineering efforts may be the best chance for survival for most of the Earth’s natural ecosystems,” Daniel Schrag, director of the Harvard University Center for the Environment, has written. However, he noted, perhaps the ecosystems “should no longer be called natural if such engineering systems are ever deployed.”
Another school of thought argues that the new world-altering technologies are likely to have much the same impact as the old world-altering technologies, only with higher stakes. Consider the example of chlorofluorocarbons. These compounds were first synthesized in the late 1920s in the hope of solving the problems caused by early refrigerants, such as ammonia, which were toxic. Billions of pounds of chlorofluorocarbons were produced before it was discovered, in the 1980s, that the chemicals were destroying the ozone layer, which shields the Earth from ultraviolet radiation.
Despite a global ban on chlorofluorocarbons, the chemicals still are being produced illegally, and every year a “hole” in the ozone opens up over the Southern Hemisphere. Shooting reflective particles into the stratosphere could further damage the ozone layer. It also could cause other problems that have not been—and perhaps never can be—fully anticipated. Critics have described the very idea of solar geoengineering as “utterly mad,” “dangerous beyond belief,” and “a broad highway to hell.”
As for me, I feel tugged in both directions. The choice we face is not whether to change the world; that decision unfortunately has been made. The decision going forward is how are we going to change it? Over the years I’ve interviewed scores of scientists, inventors, and entrepreneurs, and I’m continually impressed by how ingenious humans are as a species. But then the wind blows in smoke from 3,000 miles away, and I’m reminded of how dangerous we are as well.