A pile of discarded smartphones, laptops, and tangled cords might look like trash. In reality, electronic waste (e-waste) is the world’s fastest-growing waste stream.

On its surface, Loch Carron is a beautiful, tranquil highland sea loch on the northwest coast of Scotland. The highlands there are home to a diverse range of wildlife, including pine martens, red deer, and oystercatchers. Hidden deep below the loch’s surface is an equally beautiful haven for starfish, flame shells, and beds of maerl, a species of coral-like red algae.

In the last 25 years, countries have seen a drastic increase in concern about climate change, which has spurred policies and technological developments to reduce greenhouse gas emissions. Positive, yes, but still a far cry from what is needed to avoid the destruction of coral reefs and more than a foot of sea level rise.

Across international and US campuses, a new sustainability trend is taking root: “swap shops” and free stores, designed to reduce dorm-room waste while easing students’ financial burdens.

In the struggle against climate change, it’s easy to wish for some technology—or even magic!—that could remove Earth-warming carbon dioxide (CO2) from the atmosphere and turn it into something useful. But this mechanism already exists and is much older than the climate changes of the past two centuries.