Does agricultural trade reduce pressure on land ecosystems? Decomposing drivers of the embodied human appropriation of net primary production

Agriculture contributes to deforestation and the conversion of other terrestrial ecosystems, affecting important ecosystem functions. A growing share of the produced agricultural commodities is traded between countries. It is widely assumed that international trade reduces humanity's pressure on land ecosystems by optimizing the mix of origin, i.e. by sourcing products from countries where land is used more efficiently. We examined if recent changes in the origin of agricultural products reduced humanity's impact on a fundamental ecosystem function, the net primary production (NPP) of vegetation. We performed an index decomposition analysis on a dataset of human appropriation of net primary production embodied in bilateral trade flows of 392 agricultural products between 167 countries (eHANPP) from 1986 to 2011. We found that while changes in the origin of agricultural products globally reduced HANPP in the 1990s, this trend reversed since 1999. This turn is explained by the increased sourcing of agricultural products from tropical regions, for exports and domestic consumption. After 2008, countries – on average – increasingly sourced their agricultural products from less efficient regions than in 1986. Our results suggest that the potential of trade to reduce humanity's impact on land ecosystems has not been exploited in the recent past.