Climate smart agriculture and global food-crop production

compared to BAU. This result is suggestive of a reduced pressure on forests and other natural areas that might be environmentally significant and rich in carbon. However, the reallocation of harvested area following changes in production and prices causes other crops to take over the land freed by rice and wheat (Supplementary Discussion S11 in S1 File). Total land allo- cated to soybeans, vegetables, temperate fruits, sugarcane, and rapeseed is estimated to increase by 2 million hectares in 2050 on average across Rule 1 and 2 (1–4 million hectares) (Supplementary Table 13 in S1 File). Depending on how they are grown, these crops might have a higher carbon footprint than the crops they replace. Importantly, simulations show that increases in production of grains reduces the price of livestock feed and increases the number of animals that can be supported globally. The stron- ger the effect on prices, the greater the increase in the global cattle herd. As a result, emissions from cattle may increase by 5.4 Mt CO2e yr-1 (1.2–13.1 Mt CO2e yr-1) by 2050 and partially off- set the reductions in emissions discussed earlier (Supplementary Discussion S12 and Supple- mentary Table S14 in S1 File). 3.4 Adaptation and resilience The effects on production, prices, soil, and land use suggest that CSA practices are a form of adaptation to new climate conditions and make crop-production more resilient. A comparison with a scenario in which the effects of climate change on future crop production are removed

(a No Climate Change scenario. See Supplementary Discussion S13 and Supplementary Fig 8 Fig 3. Average change in GHG emissions by country for alternative scenarios and tailoring of CSA practices, comparing years 2010 and 2050. Negative values indicate an abatement compared to BAU and positive values an increase. Source: Authors. https://doi.org/10.1371/journal.pone.0231764.g003 PLOS ONE Climate smart agriculture and global food-crop production PLOS ONE | https://doi.org/10.1371/journal.pone.0231764 April 29, 2020 10 / 19