Historical emissions for the period 1990-2021 are from PRIMAPhist dataset (for energy, industry, agriculture and waste) (Gütschow et al., 2022a).
Energy emissions for 2022 are calculated using CO2 emissions growth rate data from the Energy Institute Statistical Review of World Energy 2023 (Energy Institute, 2023). Industry’s emissions for 2022 have been estimated using GDP growth rate. We used the 5-year trend (2017-2021) to estimate emissions for the agriculture, waste and other sectors.
LULUCF data is from the third Biennial Update Report (Viet Nam Government, 2020b). These estimates are calculated using global warming potential (GWP) values from the IPCC’s Fifth Assessment Report (AR5). We have not converted these into AR4 values assuming contribution from non-CO2 gases is negligible.
The BAU emissions are from Viet Nam’s 2022 updated NDC (Viet Nam Government, 2022a). 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 derive 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
Power CO2 emissions
The emission estimates from the 8th Power Development Plan (PDP8) are based on coal and gas emissions factors derived from the IEA’s Emissions Factors for Viet Nam, and the plan’s power sector emissions targets (204-254 MtCO2e in 2030). The yearly coal and gas generation is interpolated to 2030 by taking into account the combined domestic gas and LNG-fired generation values of 157 TWh by 2030 mentioned in the plan, aligning with the overall emissions targets for 2030 (IEA, 2021b; Viet Nam Government, 2023a). The percentage of coal generation within the 2030 power mix was determined based on the anticipated 2030 generation value of 567 TWh included in the PDP8 (Viet Nam Government, 2023a).
For post-2030, sectoral current policy projections were interpolated with the 2050 power sector emissions range included in the PDP8. The upper bound of the current policies power sector emissions projections coincides with the upper bound of the range indicated in the PDP8. The lower bound of the current policy projections was calculated using the average of the growth rate of power sector emissions from both ends of the range included in the PDP8 (Viet Nam Government, 2023a).
Non power energy CO2 emissions
Non-power energy CO2 emissions are assumed to follow the same growth rate as in the APEC Energy Demand & Supply Outlook 2022 (APEC, 2022). The current policy projections takes into account the energy savings from the Viet Nam National Energy Efficiency Program 3, but do not include the World Bank funded Viet Nam Scaling Up Energy Efficiency Project which would further reduce energy demand (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 last historical year (2021) growth rate will continue, and for the upper end we assume average growth rate of the last 5 years (2017-2021) will continue.
Planned policy projections
In the PDP8, the JETP targets are included separately to the domestic targets, with the specific mention that the JETP-related objectives are to be met conditionally on a fully and substantial implementation of the Partnership by international partners. The Resource Mobilisation Plan, detailing the implementation of the mobilisation required for the implementation of the JETP, is expected to be released in November 2023 (European Commission, 2022a).
Hence, we have accounted the Planned Policy projections as the emissions that would result from a scenario where the “commitments under JETP are fully and substantively implemented by international partners” (Viet Nam Government, 2023a). The method used for determining power CO2 emissions in the Current Policies scenario was applied in the Planned Policy scenario, using the 170 MtCO2e target instead of the domestic ones. For post-2030, power sector emissions are interpolated to the lower end of the range included in the PDP8 (Viet Nam Government, 2023a).
Viet Nam's National Climate Change Strategy (NCCS) establishes emission limits for each sector by the year 2050: the energy sector is set at 101 MtCO2e, agriculture at 56 MtCO2e , industrial processes at 20 MtCO2e , and waste at 8 MtCO2e . These sectors collectively will amount to 185 MtCO2e of residual emissions by 2050. Additionally, the Vietnamese governments assumes negative emissions from the LULUCF sector of 185 MtCO2e by 2050, resulting in a net zero emissions outcome by 2050. For this reason, we assume 185 MtCO2e of residual emissions remaining in Viet Nam’s net-zero target year of 2050.
The NCCS, however, does not explicitly mention the global warming potential (GWP) utilized for estimating emissions. According to the NCCS, the percentage reduction targets from BAU emissions for each sector, aiming for net zero by 2050, are as follows: energy sector 91.6%, agriculture 63.1%, industrial processes 84.8%, waste 90.7%, and LULUCF at 90%. We have validated these percentage reduction figures against BAU emissions in GWP AR4, as indicated in the Nationally Determined Contributions (NDC) of 2022 (Viet Nam Government, 2022a).
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.