When crops fail, forests follow: Agricultural shocks and deforestation in Zambia

TL;DR

This study finds that agricultural shocks from pests can lead to increased deforestation as farmers expand farming or produce more charcoal.

Contribution

The paper reveals that agricultural productivity shocks can paradoxically increase deforestation through coping strategies like charcoal production.

Findings

Farmers facing severe pest outbreaks increased deforestation through agricultural expansion and charcoal production.

Deforestation rates doubled in Zambia following a fall armyworm outbreak.

Remote areas and wealthier households showed lower deforestation responses to the pest shock.

Abstract

This article estimates how farmers respond to a negative agricultural production shock from an invasive pest. While one might think that decreasing the productivity of agricultural land would lead to lower demand for agricultural land and thus lower rates of land conversion, we find that those farmers facing the largest pest outbreak deforest more through expanding agricultural land and increasing charcoal production. This effect was particularly pronounced for farmers who have greater access to markets, but lower for wealthier households. Along with related work, our results suggest that households with more available mitigation options are less likely to turn to charcoal as a coping strategy.

As climate change makes agricultural production shocks more frequent and severe, it is vital to understand their effect on farmer welfare, land use, and deforestation. Theoretically, a change in agricultural productivity could increase or decrease deforestation by changing demand for agricultural land and/or through the consumption of forests as a coping strategy. This paper uses the introduction of a crop pest to sub-Saharan Africa to estimate the effect of a negative agricultural productivity shock on deforestation. Using primary household data, we first find that farmers who were exposed to higher levels of fall armyworm saw substantial decreases in yield and food security. Using estimates of fall armyworm suitability in conjunction with machine-learning models of maize yields and deforestation, we find that the introduction of the fall armyworm induced a doubling of the deforestation rate in Zambia in the 3 y following the outbreak. This increase was driven both by increased agricultural land expansion and increased charcoal production as a coping strategy. These responses vary substantially over space. More remote areas experienced 23% lower FAW-induced deforestation compared with the sample average, suggesting that farmers with access to maize and charcoal markets may have increased deforestation as a response. Wealthier areas were also less likely to deforest in response to FAW pressure. In sum, our results suggest that negative agricultural productivity shocks may lead to a negative climate feedback, with farmers engaging in emissions-increasing strategies in response.

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