"The number of people on Earth is expected to grow from 6.5 billion to about 9 billion by 2050. That much is relatively uncontroversial. But recently, we’ve seen disparate views emerge as to how this population growth will affect the planet.
Four decades after publishing The Population Bomb, Paul Ehrlich, for one, is still a firm believer that overpopulation—and along with it, overconsumption—is the central environmental crisis facing the world. In an opinion piece for Yale e360, he and Anne Ehrlich write: “Many human societies have collapsed under the weight of overpopulation and environmental neglect, but today the civilization in peril is global. The population factor in what appears to be a looming catastrophe is even greater than most people suppose.” The reason, say the Ehrlichs, is that each additional person today on average causes more damage to humanity’s life support systems than did the previous addition. And because Homo sapiens are smart creatures, we have already farmed the richest soils and tapped the most abundant water sources. Therefore, to support more people, it will be necessary to move to poorer lands, dig deeper wells, and spend more energy to transport food and water to increasingly distant homes and factories. Population, the Ehrlichs aver, remains an underacknowledged apocalypse in waiting.
Others, however, take a markedly different view. In the recently published book, The Coming Population Crash, and in a series of articles also for e360, environmental journalist Fred Pearce looks at the same demographic trends and sees very good news. “The population bomb is being defused at a quite remarkable rate,” he writes. “Women around the world have confounded the doomsters and are choosing to have dramatically fewer babies.” He then goes on to cite declining fertility rates in countries across Europe, Asia, and Latin America. And in Africa, where high fertility remains the norm, Pearce is optimistic that those extra people can provide a way out of the continent’s poverty trap. Bad agriculture, not population growth, he contends, is the continent’s main predicament—and in this essay, he describes how more people, employed on ecologically friendly, small-scale farms will be key to African sustainable development. Chris Reij, a Dutch geographer whom Pearce interviews for the article, concurs. “The idea that population pressure inevitably leads to increased land-degradation is a myth,” he says. “It does not. Innovation is common in regions where there is high population pressure.”
Consumption, not population, Pearce concludes, is the main problem confronting human society today. After all, he writes, “virtually all of the extra 2 billion or so people expected on this planet in the coming 40 years will be in the poor half of the world.” Assuming per capita emissions remain roughly where they are today, those 2 billion poor people will only boost the developing world’s share of greenhouse gas emissions from 7 to 11 percent. In other words, achieving zero population growth—even if it were possible—would barely touch the climate problem. The real culprits, according to Pearce, are not “generations of poor not yet born” people, but the stable population in the developed world with its gigantic ecological footprint."***
"The paradox embedded in our future is that the fastest way to slow our population growth is to reduce poverty, yet the fastest way to run out of resources is to increase wealth. The trial ahead is to strike the delicate compromise: between fewer people, and more people with fewer needs, in a new economy geared towards sustainability. The easy part is birth control. The hard part, as Paul and Anne Ehrlich write, is that we still don’t have condoms to prevent over consumption, or morning-after pills to reverse unwanted buying-sprees."
"So, in all of this doom and gloom, is there any good news?
Yes: not too long ago, demographers were forecasting that global population by 2050 would reach 10 to 12 billion, instead of the 9 we expect today. And when I was a kid, people were talking about 15 to 18 billion people by 2050. As population forecasts have been revised over the years, they have generally been revised downward.
Fortunately, population growth in the world appears to be slowing faster than anyone forecasted, largely through voluntarily measures (with the exception of a few states like China), while simultaneously improving human welfare around the world. The demographic transition appears to be working. People, all across the world, are choosing to have smaller families.
The bad news is that consumption appears to be still increasing rapidly, with no end in sight. So far, there hasn’t been a negative feedback on consumption, telling us to slow down. The rich want to be richer. Big consumers want to consume even more. It’s an endless treadmill, and no one knows how to get off. Instead of the “Population Bomb” of the 1960s, we now have an even larger “Consumption Bomb”, and we don’t now how to diffuse it. And this bomb may well define our relationship to the environment for the 21 century and beyond."