Air pollution. Traffic. Animals dying. Habitat loss.

All of these issues are side effects of urbanization, according to the United Nations (UN). But, with a new rewilding solution that is being tested in the United States, these problems could be significantly mitigated.

Urbanization refers to the movement of people to towns and cities along with the increased amount of land being altered for urban purposes. While the UN reported that urbanization has some benefits like increased job opportunities and less poverty, it is important to note the harmful consequences of transforming land into urban areas. 

Urbanization displaces and kills many plants and animals, contributing to habitat loss as more wilderness is replaced by buildings. Furthermore, the factories and buildings that are a direct product of urbanization create air and water pollution that is detrimental to the environment and human health. National Geographic found that urbanization has even created higher levels of lead in the air, which is an extreme health risk to all life on Earth.

But, a wildlife biologist at Yale University and the University of Michigan has made it her mission to find a solution to the aforementioned problems of urbanization. Nyeema Harris and her colleagues have executed rewilding efforts to combat the urbanization issue of animal extinction. In 2019, UN data showed that almost one million plant and animal species are nearing extinction and falling into the “threatened” category. Harris and her team thought of the rewilding approach as a solution.

Rewilding is the process of revitalizing and protecting natural areas that are threatened by cities. Through rewilding, humans help start the process of conservation by removing immediate urbanization obstacles; then, humans step aside and let the environment naturally continue the task. The Associated Press reported some examples of rewilding: dam removal, reintroducing predators to certain locations to stabilize ecosystems, and building tunnels to assist animal migration paths that have been ruptured by roads.

A prime example of the success of rewilding took place in Detroit, Michigan. Scientists worked with the government to reintroduce ospreys and peregrine falcons. More pesticides were banned in Detroit, prompting bald eagles to return to the skies. Restrictions on water pollution and government-arranged river cleanups increased the number of beavers, whitefish, and sturgeon along with wild celery.

John Hartig, a Detroit lake scientist who helped supervise the rewilding process, explained the strengths of the city’s rewilding.

“Detroit is a stellar example of urban rewilding. It’s been more organic than strategic. We created the conditions, things got better environmentally, and the native species came back,” Hartig said.

Some critics of rewilding have been against the process because it can result in less orderly lawns in favor of eco-friendly systems that can be more weedy or diverse. However, rewilding experts believe this is a small and reasonable loss, as many cities will experience improved health for people, animals, and plants.

While rewilding is not a perfect solution, multiple case studies have shown that it is a promising solution to the ongoing negative effects of urbanization.

A landscape after undergoing the process of rewilding.