In the creation story of , God creates humans and invites them into the world: “Be fruitful and increase in number” God tells them. “Fill the earth and subdue it.”
It’s a story that was passed along between generations for thousands of years before it was written down, and in those early years there was plenty of earth to fill. In the 6th millennium BC the whole human population was 5-7 million in total – less than the population of London today spread across the whole planet. There were plenty of areas that nobody had reached yet. Humanity was still moving from a nomadic hunter-gatherer existence to settled agriculture. Wild animals were being domesticated. Rivers were being tamed as irrigation was being used for the first time. The ‘subduing the earth’ that Genesis speaks of had a context, and it was an exciting and forward-thinking idea.
The process of filling is not endless. One fills something until it is full. And then you stop. That is obvious enough that presumably God didn’t feel the need to spell it out. So is the world full? How would we know? And how do we stop?
If we were to look around us, there is plenty of physical space. Unlike a tree though, the actual ground a person stands on is no indicator of their land requirements. Each of us needs cropland and pastureland to grow our food. We need a slice of forest to provide the timber and paper that we use, and more to absorb the carbon dioxide we emit. We need freshwater, and some ocean for our fish. , each of us needs 4.8 hectares. Together we need more productive land than Britain has, and we rely on other countries running a surplus. So by that measure, Britain is more than full.
Globally, humanity started drawing more from the earth every year than the planet can renew back in the 1970s, and we’ve added 3 billion people since then. Footprint isn’t the only measure of course. We could look at how much of animal life is wild, and how much is domesticated – something I wrote about recently. By weight, 97% of animal life on earth is humans and our farmed animals and pets, with just 3% wild. That’s pretty full. Or we could look at ‘‘, planetary boundaries, or how much of the earth’s surface has been .
There’s no definitive answer of course. But we can see what it looks like to reach capacity. Herman Daly, in an article on, gives the example of fishing. In an empty world, if you want to catch more fish you just send more boats and more fishermen. In a full world, that basic rule no longer applies. The fish aren’t there to be caught, and sending more boats won’t make any difference. The limiting factor isn’t our ability to exploit a resource, but the resource itself.
Or take a region trying to grow more food. In the past, we could clear more land and add farms and farmers. But what if a region has tapped its rivers or aquifers to maximum capacity? The limiting factor is not the number of farmers, but the underlying natural resource.
How do we live well in a full world? We could talk about reducing our consumption and shrinking our ecological footprint. We could talk about how best to ensure an earlier peak in human population. But most of all it’s a mindset. Our institutions, our aspirations, and our measures of success are all calibrated for an empty world. The from last week serves as a concise articulation of the priorities of the world’s most powerful people. Across its 8 pages it pledges to “support growth”, “boost growth”, “promote growth”, “stimulate growth”, “enable growth”, “drive growth” “continue advancing growth” create “engines for growth”, and “introduce new sources of growth”.
Therein lies our challenge. The biggest obstacle to a sustainable future is our failure to recognise that we have already filled and subdued the earth. Now it’s time for a new challenge: making ourselves at home in a full world.