Potential effects of climate change on Brazil's land use policy for renewable energy from sugarcane

Brazil, in its intended nationally determined contribution protocol on the Paris Agreement, set to enhancement the usage of energy from sugarcane. To sustainably meet this goal, the Brazilian government rely on the Sugarcane Agroecological Zoning (SAZ). The SAZ, based on soil, climate, and land use conditions, defines as suitable 63 million hectares (Mha). Such an area would suffice the future demand for sugarcane. However, climate change impacts on the climate conditions necessary to grow sugarcane may promote a mismatch between the SAZ and future suitability. Our goal is to examine the effects of climate change on the SAZ policy. We developed ecological niche models to identify the suitability criteria and generate scenarios under 17 global climate models listed in the IPCC 5 for 2050. An ensemble of the 17 scenarios identifies areas of estimation congruence thus indicating smaller uncertainty regarding the suitability of these areas. Areas of high congruence (above 70% of prediction) encompass 1.53 Mha by 2050, a reduction of 97.5% compared to SAZ. Including areas of high congruence outside of the SAZ increases the suitable area to 7 Mha. The public and private sector in Brazil needs to develop large-scale adaptation strategies such as improving the research cycle of sugarcane varieties and reducing yield gaps by advancing the management of sugarcane fields to propel Brazil into fulfilling its Paris Agreement commitment.