Cities and their even larger, fast-growing siblings — megacities (more than 10 million people) and hypercities (more than 20 million people) — aren’t just products of human civilization that dramatically affect their surrounding ecosystems. They’ve emerged as unique ecosystems in their own rights.
In “Global Change and the Ecology of Cities,” published in the Feb. 8 issue of Science, a team of researchers from Arizona, New Zealand and Australia argue we need to focus more on cities — and not just the “natural” world — to ensure a sustainable future.
“Cities, and the people in them, will ultimately determine the global biodiversity and ecosystem functioning,” says Jianguo (Jingle) Wu, one of the paper’s co-authors and an ecologist at Arizona State University’s (ASU) School of Life Sciences. “Sustainable urbanization is an unavoidable path to regional and global sustainability.”
The paper’s authors advocate a global approach to urban development that recognizes cities both cause and respond to environmental change. That strategy echoes an emerging school of thought that views cities as organic entities — a sort-of Urban Gaia, if you will — things that consume resources, produce waste and interact with their surroundings.
While the concept might sound bizarre, it might ultimately prove to be as effective a philosophy as James Lovelock’s Gaia view of Earth. After all, cities around the world are doing nothing but metastasizing, absorbing an ever-flowing influx of rural people either displaced from their traditional lifestyles and/or looking for a better future in a modernizing world.
As of today, according to TaskForce MegaCities, the world has anywhere from 16 to 39 megacities (population thresholds for meeting “megacity” status vary). In just seven more years, that number could approach 60. The trend is especially strong in Asia, which could be home to as many as 10 hypercities by 2025, according to one estimate.
Sustainably managing such urban growth could be key not only to better living in cities themselves, but a better Earth overall.
“The relatively young and highly interdisciplinary field of urban ecology has demonstrated how well-designed cities can actually have less overall impact on the environment than equivalent dispersed rural populations,” said Jonathan Fink, director of ASU’s Global Institute of Sustainability. “The kind of counter-intuitive research results described in (the Science) paper show how an ecological perspective can help urban planners and engineers find ways for society to live more harmoniously with nature.”