The ecologists who think moving to cities will save the planet

Source: Wired | Matt Reynolds

As far as professions go, conservationists are not known for their optimism. And, with the future of the planet looking so bleak, who can blame them? By 2100, the world is on track for more than three degrees of warming, sliding past the targets set by the Paris climate accord in 2015. By the middle of this century, between 15 and 37 per cent of species sampled in one study could be completely gone. In 2016, it became clear that giraffe populations had declined by 40 per cent over the last 30 years, earning the animals a spot on the endangered species list.

But Eric Sanderson, a landscape ecologist at the Wildlife Conservation Society, is cautiously optimistic about the future of our planet. He thinks that if we can hang in and refrain from completely destroying the environment over the next 80 years, the world might just have a chance at recovering from everything humans have inflicted on it.

“If we make the right moves now, in the 21st century, then the 22nd could be pretty great, and the 23rd would be really awesome,” he says. Sanderson set out his optimistic vision for the future of biodiversity in a paper recently published in the journal BioScience arguing that, if it can get through the current conservation crisis, Earth’s biodiversity is on the brink of a recovery.

The reason for Sanderson’s optimism has much to do with global demographic trends as it does conservation. His starting point is the well-established theory that, as population growth continues to decline after peaking in the 1960s, the number of humans on the planet will level out at around nine billion by the year 2100. At the same time, Sanderson predicts, economic growth will continue to lift hundreds of millions of people out of poverty, and that by 2100 up to 90 per cent of the world’s population will live in towns and cities.

For more traditional conservationists, this is a recipe for environmental disaster. “Generally, as we get wealthier we get greedier,” says Simon Stuart, conservation director at environmental charity Synchronicity Earth. As incomes rise, we eat more meat and processed foods, both of which are highly damaging to the environment. We start driving cars manufactured in far-flung places that pollute the atmosphere, and buy gadgets filled with materials hauled out of the Earth at great cost to the environment. In short, economic growth leads to more consumption, and consumption is bad news for the environment.

But Sanderson thinks there might be some ecological upsides to economic growth. When people get more wealthy, they tend to move to cities, and urban living are much efficient from a planning point of view. For a start, cities allow more people to can share infrastructure like sanitation, water supply, hospitals and schools. City living also makes travel distances shorter, and shared transportation more desirable, lowering the environmental impact of transportation per person.

Even the idea that as we get wealthier we consume more has its limits, Sanderson claims. It’s true that, for the very poor, every small increase in income is likely to result in more consumption, but this trend starts to flatten out when people get wealthier and proportionally spend more on financial services and housing and less on consumer goods. “As you get wealthier, maybe you still buy a car but you’re buying a fancier car,” says Sanderson. The financial costs of consumption go up, but that doesn’t necessarily mean that the environmental cost increases at the same rate.

This all leads to the conclusion that – for people at the same income level – living in towns and cities is more environmentally-friendly than living in rural areas. One studyof consumption in New York City found that the average New Yorker consumes 74 per cent less water, uses 35 per cent less electricity and produces 45 per cent less waste per person when compared with the average American. Over the next 35 years, the world’s cities and towns are expected to grow by 2.5 billion people, and by a happy coincidence this might just be a more ecological way to live.

This still leaves us with some huge environmental headaches, says Robert McDonald at The Nature Conservancy. McDonald researches the environmental impact of cities, and thinks about ways to build urban environments without reducing biodiversity. “We’ll probably build more homes in the next 20 year than exist in the whole of Europe now,” he says. “How you build those cities is going to be a huge deal.”

This will mean building cities in a way that doesn’t have a negative impact on the environment around them. Over the last century, as city populations exploded, they grew in an unpredictable and unplanned fashion, encroaching onto important environmental areas and squeezing out protected species. But some future cities are already being built with the environment in mind. The Xiong’an New Area is a vast spread of wetland 100 kilometres to the southwest of Beijing that has been earmarked as a new city to home millions of people who would otherwise be crammed into Beijing. As part of the development, the Chinese government is planting millions of trees and plans to leave 70 per cent of the city covered with water or greenery.

In many places where populations are skyrocketing, however, developing sustainable cities is nowhere near that easy. Sub-Saharan Africa has some of the fastest population growth rates in the world and those countries may struggle to build new cities in a sustainable way. “Every country has its own quirks in how its cities grow,” says McDonald, and there’s no guarantee that cities will continue to get denser anyway. Driverless cars might end up increasing urban sprawl as people begin to tolerate longer commutes now they can spend that time doing something other than being stuck behind the wheel. “We just don’t have any sense how that will change the shape of urban growth,” McDonald says.

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