Away from the bright lights of the city, if you look up at the night sky you will see an ocean of bright stars. But in the illuminated concrete jungles we humans have built ourselves, it’s a different story.

This year, Earth Hour was observed on March 26. The annual tradition, started by the World Wildlife Fund (WWF) in 2007 in Sydney, Australia, was created to raise awareness for climate change. Those celebrating turn off all their electrical appliances for one hour. It also draws attention to another serious problem that the world is currently facing — the threat of light pollution.

Light pollution happens when too much man-made light harms nature. Scientists have found that it is especially harmful to nocturnal animals. These creatures rely on the natural light cycle provided by the movement of the sun to help coordinate their sleep cycles. When this is disturbed by constant bright lights from man-made structures, it can seriously disorientate the animals and harm their physical health. “Wildlife species have evolved on this planet with biological rhythms — changing that has profound effects,” said Travis Longcore, a biogeographer with the Urban Wildlands Group in Los Angeles, US. A lack of darkness at night can also cause difficulties for animals in other ways.

Newly hatched (孵化) baby sea turtles rely on the brighter horizon over the ocean to guide them from the beach to the sea. However, with artificial lights next to the oceans, the small animals are easily led away from the right path. “Hatchlings are attracted to lights and crawl inland, or crawl aimlessly down the beach, sometimes until dawn, when predators or birds get them,” said Michael Salmon, a biologist at Florida Atlantic University in Boca Raton, Florida.

Artificial light has caused a “drastic change” to the natural environment of animals, research scientist Christopher Kyba told the International Dark-Sky Association. “Predators use light to hunt, and prey (猎物) species use darkness as cover,” Kyba explained. If a predator has such an extra advantage in hunting its prey, this can lead to an imbalance in the ecosystem as the hunted species are no longer able to maintain their population when they become over-hunted.

In Melbourne lies an 87-square-meter, three-story, two-bedroom and one-bathroom house. That may sound like a real property advertisement, but it could be the home of the future.

Made from organic materials and run on sustainable (可持续的) energy, the building, known as “The Greenhouse”, is completely zero waste. It was designed by zero waste advocate Bakker, as part of his Future Food System housing experiment. “The greenhouse is inspired by nature — it’s an ecosystem where nothing is wasted,” Bakker says.

Organic waste is fed into a biodigester where it ferments (发酵) and turns into gas for cooking or fertilizer for produce; rainwater is harvested and used for irrigation and a specific system, where plants grow using waste from fish; and hot steam from the shower enables a wall of mushrooms to boost. The house is designed, says Bakker, with the roof as the foundation, loaded with 35 tons of soil, which provides fertile (肥沃的) ground for produce — more than 200 plant species grow on the roof, as well as insects, snails, fish and chickens.

The site is more than just a model home; it’s been a real one for Jo Barrett and Matt Stone, who were chefs at the small in-house restaurant. “To be able to grow and produce food on a tiny footprint in the city and turn it into exciting dishes is completely unique,” says Stone.

Through the project, Bakker wanted to demonstrate he could feed a family with his design. “I think we’ve proved that it’s actually more productive than I imagined,” he says. “We’ve harvested 35 kilos of potatoes from a square meter.”

He hopes the example will offer a blueprint to future homes and an alternative to current food system, which is to blame for over a third of the world’s greenhouse gas emissions (排放). Creating a circular system could also greatly reduce food waste.

“We’re the only species that generates waste. In nature, there is no waste; everything becomes a food source for something else,” says Bakker. “If we transform to a circular system, we have so much potential to stop the destruction of wilderness and forest.”