Soil & Land

Rainfall anomalies ‘significant driver’ of cropland expansion

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Repeated annual rainfall shortages contribute to cropland expansion and deforestation in the developing world, according to a study.

Land clearing is a significant contributor to climate change.

To gain insight into the balance between developmental goals, such as food security, and environmental goals, such as habitat protection, Esha Zaveri, Jason Russ, and Richard Damania explored how rainfall variability contributes to cropland expansion.

The authors examined land cover and rainfall data from 171 countries over the period 1992-2015.

The authors divided the data into grid cells and noted which years represented a rainfall anomaly for each grid cell, either above or below average.

In the 1-5-year period following a drier-than-normal year, cropland expanded in the area.

The authors noted comparable reductions in forest cover during these periods.

The effects were limited to developing countries, where they represented 9% of cropland expansion and where smallholder farming dominates agriculture.

Regions where water infrastructure, such as irrigation, buffers yield from rainfall anomalies did not show similar cropland expansion.

According to the authors, understanding how rainfall anomalies affect cropland expansion and deforestation is crucial as climate change intensifies.

Source: PNAS