Remaining Loyal to Our Soil: A Prospective Integrated Assessment of Soil Erosion on Global Food Security

Abstract

Soil loss by water erosion represents a key threat to land degradation worldwide. This study employs an integrated quantitative modelling approach to estimate its long-term global sustainability impacts. The global biophysical model estimates a mean increase of soil erosion rates of between 30 and 66% over the period 2015–2070 under alternative climate-economic scenarios, assuming different greenhouse gas concentration trajectories. In a subsequent step, projected soil erosion rates are converted into land productivity losses and inputted into an economic global simulation model to identify those regional hotspots where the greatest market tensions are expected to occur.

The headline result is that of a global economic contraction of up to 625 billion US$ by the year 2070. Moreover, soil erosion represents an acute challenge to food security in vulnerable regions (Africa and some tropical regions), where for certain crops (particularly oilseeds) the threat of shortages is potentially significant. Under the worst-case scenario, global primary agricultural production losses could amount to 352 million tonnes by 2070. Exploring different long-term socioeconomic-environmental pathways confirms the merits of sustainable management practises in coping with market and environmental stresses arising from soil erosion that limits the global increase of land used for food consumption to 115,000 km2 above the long run baseline. Finally, free (and fair) trade is essential to allow less affected regions to expand (marginally) their production, thereby cushioning the market tensions that are expected to occur in more acutely affected areas of the world.