Historical emissions for the period 1990-2019 are from PRIMAPhist dataset (for energy, industry, agriculture and waste) (Gütschow et al., 2021).
2020-2021 historical emissions estimate
Energy emissions for 2020 and 2021 are calculated using CO2 emissions growth rate data from BP Statistical Review of World Energy 2022 (BP, 2022a). Industry’s emissions for 2020 and 2021 have been estimated by, assuming constant elasticity of emissions intensity. We used the 5-year pre-COVID trend (2015-2019) to estimate emissions for the agriculture, waste and other sectors.
LULUCF data is from the Biennial Update Report 3 (Viet Nam Government, 2020a). These estimates are calculated using global warming potential (GWP) values from the IPCC’s fifth assessment report. We have not converted these into AR4 values assuming contribution from non-CO2 gases is negligible.
NDC and other targets
The BAU emissions are from Viet Nam’s 2022 updated NDC (Vietnam Government, 2022c). The BAU scenario for GHG emissions assumes “medium economic development” and corresponding energy demand. The pledge emissions have economy wide coverage. The BAU starts from 2014 inventory data, with projections for 2020, 2025 and 2030.
The 2022 updated NDC provides a breakdown of sectoral emissions reduction in GWP AR4 in 2030. We sum up the reduction amount from energy, agriculture, waste and industry in 2030 and subtracted these from BAU emissions in 2030 to derived the NDC targets.
The CAT methodology for rating NDCs is based on GHG emissions from fossil fuels. We exclude the LULUCF sector from our calculations. For more information, please refer to the CAT methodology section.
Current policy projections
Viet Nam’s current policy projection for energy related CO2 emissions are based on the reference scenario of APEC Energy Demand & Supply Outlook 2022 (APEC, 2022). The emissions of energy related non-CO2 greenhouse gases, agriculture and the waste sector are based on non-CO2 emissions projection of US-EPA (U.S. Environmental Protection Agency, 2019).
For the lower end of industrial emissions, we assume that the growth rate of 2019 will continue, and for the upper end we assume average growth rate of pre-COVID 5 year (2015-2019) will continue.
Global warming potentials
The CAT uses Global Warming Potential (GWP) values from the IPCC's Fourth Assessment Report (AR4) for all its figures and time series. Assessments completed prior to December 2018 (COP24) used GWP values from the Second Assessment Report (SAR).