Images of wildfires engulfing trees, often with fleeing residents cast in silhouette, have become one the most ubiquitous illustrations of how global warming is affecting the West, especially California. But in a recent analysis, fire ecologist Jon Keeley saw a remarkable pattern that he feels has been overlooked by media, activists, and politicians.
Climate change isn't causing most fires. People are.
Keeley, a UCLA professor and senior research scientist with the U. S. Geological Survey's Western Ecological Research Center, studied records of tens of thousands of wildfires that occurred in California from 1919 to 2016. Although lightning strikes were responsible for as many as a quarter of all fires in several inland mountain regions, in two thirds of California counties, human activity sparked 95 percent of all wildfires. In Alameda County, 98 percent were attributed to human origins, in Contra Costa 93 percent, in Marin 99 percent.
Keeley believes that population growth is equally or even more responsible than global warming as the proximate ignition source of California's wildfire plague. "Politicians just want to say that global warming is the big problem," he said. "To me, climate change is a distraction from the population problem. ... They're comfortable with global warming because they can't be held accountable, whereas population growth is something that much more directly affects their constituents, right now."
Although U.S. birth rates fell to a 32-year low in 2018, neither California nor the Bay Area is immune to global population trends. Our regional population has grown profoundly — primarily caused by people moving to the Bay Area, mostly other Americans. And they don't just bring wildfires.
The Bay Area's 7.8 million people — 600,000 more numerous than in 2010 — are the source of urban sprawl and housing shortages, congested highways and crowded trails, air pollution and species extinction. By the 2040s, the Bay Area could be home to another 1.7 million people on top of that, and no matter how much new housing is constructed, some observers believe it won't ever be enough to outpace the demand for it. "It's an unsolvable problem," said Randy Rentschler of the Metropolitan Transportation Commission. "The Bay Area is choking on its own success."
Human population growth is the root cause of just about every resource-related problem afflicting both the Bay Area and global society. By 2100 — the year now so often treated as the forecast horizon for humanity — nearly all of the 7.3 billion humans currently alive will be gone. But in their place could be 11 to 12 billion others, dominating a planet overrun with noise, litter, livestock, and pollution, and stricken by resource depletion, ocean acidification, farmland degradation, water-supply overextension, and the cascading effects of climate change.
"We think about population growth in the most incredibly selfish way," said sustainable seafood activist Casson Trenor, who once worked for Greenpeace and recently authored a children's book about humans' relationship with the ocean. "There will be a whole lot of new people who didn't ask for this planet, who didn't ask for this situation, but will be brought into this world by our choice, and it's our responsibility to provide for them the best world that we can."
Although seldom invoked by name, population growth gnaws at the fabric of our lives and politics. The populist wave that has transformed politics across the developed world in recent years is largely a backlash to rising immigration from countries with higher birth rates and less economic opportunity. Economist David Zetland, who studied at U.C. Davis but now lives and teaches in the Netherlands, summarizes that political worldview as "white people who are afraid of darker-skinned people having more children." Consider for instance the infamous words of Donald Trump, who last year objected to migrants entering the United States from "shithole countries" (with Black populations) such as Haiti or in Africa, but specifically welcomed the (primarily white) residents of Norway.
Yet even though population trends lie at the very heart of our national politics, the topic is oddly absent from contemporary conversations.
"It dwarfs everything going on now, but people don't acknowledge it or if they do, it's sort of a sky-is-falling-let's-talk-about-something-else approach," said Trenor, who also cofounded San Francisco's Tataki Sushi and Sake Bar, widely applauded for focusing on the sustainability of its seafood. He calls the planet's growing population "the 800-pound invisible gorilla in the room."
So why don't we talk about it?
'Is It OK to Still Have Children?'
People have worried about overpopulation for at least 300 years. Late in the 18th century, Thomas Malthus theorized that the rapid growth of the human population would be checked by a limited capacity to grow enough food.
But Malthus was wrong; his forecast did not come true. Population growth was real enough, but it was accompanied by advances in farming, sanitation, manufacturing, medicine, and other realms that enabled more and more humans to live in closer and closer proximity, even while extending their average ages and qualify of life.
Following the 1968 publication of a low-budget paperback called The Population Bomb, many people again believed civilization was on a crash course with doom. The book, which sold millions of copies and made a celebrity of its author, Stanford professor Paul Ehrlich, warned that the human population had exceeded the Earth's carrying capacity and would experience catastrophic famines.
Ehrlich issued his warning precisely at the modern peak of the population growth rate; globally, our numbers were rising more than 2 percent per year at the time, double today's rate. The author viewed those trends as unsustainable. In an interview in 1970 with CBS, two years after publication of The Population Bomb, he declared, "Sometime in the next 15 years, the end will come, and by 'the end' I mean an utter breakdown of the capacity of the planet to support humanity."