Rebound effects may undermine the benefits of upcycling food waste and food processing by-products as animal feed in China

Abstract

Upcycling food waste and food processing by-products as animal feed could reduce livestock-related emissions, but rebound effects, where lower feed costs lead to livestock expansion, may diminish these benefits. Here, using an integrated environmental–economic model, we assess the impacts of this upcycling in China’s monogastric livestock production. We find that upcycling increases monogastric livestock production by 23–36% and raises total acidification emissions in China by 2.5–4.0%, while domestically total greenhouse gas emissions decrease by 0.5–1.4% through less waste sent to landfill and incinerators and a contraction in non-food production. This upcycling enhances food security and has substantial knock-on effects beyond the agricultural sectors, through influencing sectoral employment, gross domestic product and household welfare. Although emission taxes could absorb the rebound effects on emissions, they may also negatively impact food security and shift emissions abroad, depending on tax levels. A scenario analysis and integrated environmental–economic model demonstrate that repurposing food waste and food processing by-products for animal feed has asymmetric effects on food security and environment sustainability.