Two Billion Humans
Here’s a bit from an interview I enjoyed with Eileen Crist from the December 2020 issue of The Sun magazine, which you can read online. I appreciate that folks have done the math to figure out what a good population would be and how we could very reasonably get there. This would be an effort across generations, and who knows what will really happen anyway? We can all chip into a vision that we ourselves will never see.
Tonino: You said earlier that there are approximately 7.8 billion humans on the planet. What would be an ideal number of humans?
Crist: Many analysts are thinking of a provisional goal of around 2 billion. This figure is for a human population enjoying roughly a European standard of living, sustained by organic food production, and eating far less fish, meat, and animal products than the average Western consumer.
Of course, there is no “optimal” population number in an absolute sense, because a lot depends on the level of consumption people gravitate toward, their dietary choices, and unknown variables having to do with technological developments. But 2 billion is more optimal than where we are now and where we are headed. Two billion is what the global population was about a hundred years ago. It is a big-enough number to enable a connected global civilization to continue, with achievements in the sciences, humanities, technology, and so on. In other words, 2 billion can sustain a lively “conversation of humanity.” But it’s a low-enough number to enable the substantial protection of nature that we are discussing.
According to Cornell agronomist [the late] David Pimentel and his colleagues, 2 billion people is the estimated number that can be sustained on organic, diversified, mostly regional agriculture, with farm animals living on the land and people eating a mostly plant-based diet. This way of eating would not only be wholesome for people but good for the planet and for all other animals as well.
You might say: “Fine, 2 billion sounds good, but how do we get there?” We get there by fast-tracking two important human rights: One, full gender equity and schooling for all girls, through at least secondary education. And, two, affordable and accessible family-planning services for all. If we could bring the global fertility rate — voluntarily: I do not support coercion of any kind — to an average of one child per woman, the human population would start to approach 2 billion within four generations.
Tonino: The ecophilosopher Arne Næss said that he was pessimistic about the twenty-first century but optimistic about the twenty-second. How do you think about the future?
Crist: What Næss meant, I think, is that in the twenty-first century there will be a reckoning with how we’ve lived, what we’ve done to the planet and ourselves, and that reckoning will set in motion an awakening: a different way to go about things, a different relationship between Earth and humanity. It’s quite possible that things will play out that way — get bad, then better. In some respects it’s an optimistic prophecy. But obviously there’s no guarantee that the future will follow this trajectory. We don’t even know where we are with respect to climate change. If runaway heating happens — or a nuclear war or some other unimaginable disruption — this trajectory that Næss outlines will be impossible.