Managing solid waste to co-control carbon and nitrogen leakage in China

Solid waste disposal generates substantial carbon and nitrogen leakage, adversely affecting air quality, aquatic ecosystems, and the climate. However, the coupled cycles of carbon and nitrogen within this sector remain insufficiently understood. This study develops an integrated carbon and nitrogen budget for China’s solid waste sector from 1980 to 2023. Over this period, atmospheric carbon emissions increased 3.6-fold, reaching 34.0 million tons (Tg) C yr^-1 in 2023, while nitrogen losses peaked at 1.4 Tg N yr^-1 in 2005 before declining. By 2060, an optimized co-control strategy could reduce carbon leakage by 87 % (30.2 Tg C yr^-1) and nitrogen leakage by 96 % (0.9 Tg N yr^-1), yielding net social benefits of US$34.6 billion. Source reduction strategies, particularly waste recovery programs and Pay-As-You-Throw tariffs, are the most cost-effective mitigation options. These findings underscore the critical role of solid waste management in promoting a circular economy and achieving sustainable development.