Least Concern

The International Union for Conservation of Nature’s Red List is a database of endangered species. IUCN evaluators analyze the population and habitat needs of species and then rank their risk of extinction on a seven-point scale.

In 2008, the IUCN conducted an assessment of Homo sapiens. They concluded that humans’ risk of extinction is “least concern.”

Humans have the widest distribution of any terrestrial mammal species, inhabiting every continent on earth (although there are no permanent settlements on Antarctica). A small group of humans has been introduced to space, where they inhabit the International Space Station.

At the very least, humans help define the end opposite “extinct” on the IUCN’s scale. But a small group of scientists thinks otherwise. They argue that the combination of technological innovation and environmental exploitation that has gotten humans this far will ultimately be our downfall.

Thanks to the ravages of climate change and wildlife destruction, Frank Fenner says, humans are up next to face a severe loss of habitat and resources. It’s already clear that anthropogenic climate change endangers countless species. Fenner's camp simply adds that humans are no exception. We'll run out of fuel and arable land eventually, and “we’ll undergo the same fate as the people on Easter Island.”

Reading the entries in the IUCN Red List suggests human dominance over wildlife as a matter of course. Just see the entry on the red panda: "Red Pandas are starting to enter the pet trade, perhaps partly in response to the increasing number of ‘cute’ images on social media." It seems like nothing will stop us. But geo-microbiologist Katrina Edwards says that of the current period of ecological unrest, “The Earth could care less. We will be recorded as a minor perturbation in the Earth system. The Earth will go on. The question is: Will we?”

The basic problem is overpopulation. "As the population keeps growing to seven, eight or nine billion, there will be a lot more wars over food," says Fenner.

The idea is not a new one. Thomas Malthus’s landmark Essay on the Principle of Population (1798) is the defining text in this area. Malthus said that growth in the food supply can’t keep pace with population growth:

Population, when unchecked, increases in a geometrical ratio. Subsistence increases only in an arithmetical ratio. A slight acquaintance with numbers will shew the immensity of the first power in comparison of the second.

Malthus championed chastity and delayed marriage as a kind of proto-eugenics. He thought the imminence of human extinction was a self-evident mathematical fact. His snark is tempered by the fact that we’re still here. Thanks to technological innovations and land conversion, humans have managed not to starve yet. But could that be what’s next?