Identifying Pathways to Accomplish Brazil's NDC Through an Integrated Assessment Modeling Approach

Background: The increasing awareness about climate change and the adverse effects of global mean temperature increasing beyond +1.5 ∘ C above pre-industrial levels resulted in a historic international climate agreement in December 2015 in Paris. Countries around the globe published their intended Nationally Determined Contributions (hereafter iNDCs)–converted into Nationally Determined Contributions (NDC), committing to take actions post-2020 to tackle global warming, mainly to mitigate greenhouse gases (GHG) emissions. The Brazilian NDC established absolute emissions targets of 1.3 GtCO 2 e by 2025 and of 1.2 GtCO 2 e by 2030 (GWP-100, AR5), corresponding to reductions of 37% and 43%, respectively, compared to 2005. In this work, we studied the role that each economic sector can play to meet the Brazilian NDC through an integrated assessment modeling (IAM) approach. Results: The analysis showed that the AFOLU (Agriculture, Forestry and Land-Use) sector would contribute with mitigation amounts of 25.5 MtCO 2 e in 2025 and 145.8 MtCO 2 e in 2030, considering implementation of no-regret abatement measures (LC0) and LC10 scenario, which implies an economic effort to internalize a carbon price of US$ 10/tCO 2 e in the economy, respectively. Potential emissions reductions in the energy system would contribute to the mitigation of 60.4 MtCO 2 e in 2025 and 211.1 MtCO 2 e in 2030. Additionally, we identified critical measures with higher mitigation potential, for instance, commercially planted forests, integrated crop-livestock-forestry systems, no-tillage systems, biological nitrogen fixation application, intensification of livestock production through cattle confinement, deforestation reduction, expansion of native vegetation, and degraded pastures recovery in the AFOLU sector. Regarding the energy system, the integrated modeling demonstrated high mitigation potential in measures related to energy efficiency in the industry, waste management, and transport sectors; as well as a modal shift from individual to collective passenger transport and highways to railways and waterways to load transportation, and energy utilization of urban solid waste and effluent of treatment plants for the production of biomethane and electricity. Conclusions: Projected emissions for 2025 demonstrate that the NDC target for this year could be achieved with the LC0 scenario (carbon value equal to zero) implementation, while the NDC target for 2030 could be achieved by implementing the LC10 scenario in 2030.

MEDEAS: a new modeling framework integrating global biophysical and socioeconomic constraints

Description of the open-source MEDEAS integrated assessment modeling framework, which focuses on the biophysical and economic dimensions, restrictions and interactions arising during energy transitions.