Wastewater treatment plants can handle food scraps alongside sewage. Food waste buried in landfills decomposes without oxygen and releases methane, and even modern landfill systems let roughly 58 percent of that methane escape. At a treatment plant, food waste is blended into sludge and fed into sealed anaerobic digesters, where microbes produce methane that is captured to make electricity and heat. The leftover solids are rich in nutrients that can be turned into fertilizer. In the study's full-scale case, the plant's emissions were roughly net negative and it captured over 95 percent of methane.

Hampi is a UNESCO World Heritage Site in Karnataka, India, with more than 1,600 surviving remains spread over 4,100 hectares. It was the capital of the Vijayanagara Empire from 1336 to 1565. Travellers from Persia and Portugal described it as a prosperous, wealthy and grand city with temples, markets and farms along the Tungabhadra River. By 1500 it was estimated to be the world's second-largest city after Beijing, and probably India's richest at the time. In 1565 a coalition of Muslim sultanates defeated the Vijayanagara Empire, its capital was conquered and destroyed, and the city was left in ruins. Hampi remains a religious centre, with the active Virupaksha Temple at its heart.