Historical emissions are based on government data where the data was available (MNRE 2019; Viet Nam Government 2017b). Historical emissions from 1994 to 2013 are based on the Second Biennial Report submitted to the UN Framework Convention on Climate Change (UNFCCC) (Viet Nam Government 2017b). The latest emissions data (year 2014) was also included from Viet Nam’s third national communication to the UNFCCC (MNRE, 2019). Interpolations were used in the years not reported. PRIMAP data is used for years 1990 to 1994 (Gütschow et al., 2019).
Data for CO2 emissions in the agriculture sector is missing in the government sources but CH4 and N2O are included (MNRE 2019; Viet Nam Government 2017b), which account for the larger share of emissions in the agriculture sector.
The government data on industrial processes and product use (IPPU) only includes CO2 (MNRE 2019; Viet Nam Government 2017b). We have added non-CO2 emissions from the US EPA (2019a) for full coverage of industry sector emissions.
Emissions from 2010 were recalculated by the government in 2014 (Viet Nam Government 2017b). The NDC uses a different figure for 2010 emissions, with a difference of 2.7%, amounting to 273 MtCO2e (excl. LULUCF, incl. IPPU) (Viet Nam Government 2017b).
NDC and other targets
The target emissions are found in Viet Nam’s updated NDC (Viet Nam Government, 2020a). The BAU scenario for GHG emissions assumes economic growth in the absence of climate change policies. The target emissions have economy wide coverage. The BAU starts from 2014 inventory data, with projections for 2020, 2025 and 2030. Interpolations were used in the years not reported. The updated NDC includes a breakdown of sectoral emissions. The CAT removes LULUCF to focus on the emissions intensive sectors of industry and energy.
Current policy projections
The current policy scenario is based on projections from APERC (2019a) business as usual (BAU) scenario. The APERC BAU scenario projects CO2 emissions of current and planned policies in the energy sector. The energy sector covers over 50% of Viet Nam’s emissions.
The APERC (2019a) BAU scenario has a number of assumptions: The optimisation and capacity of the power mix is based on the Revised PDP7. Electricity use from appliance and buildings reflect economic growth and urbanisation. Industry plays a key role in the economy, where steel, iron and cement industry continue to dominate the industry sector. Regarding transport, energy elasticity is linked to GDP consistent with the base year fuel mix. Biodiesel is not included as it assumes no market penetration of the product. It is assumed that increases in the number of vehicles continues. The energy supply mix matches the sectoral plans, including coal and natural gas targets, and LNG terminal plans. The production of oil is based on available reserves and historical data. The scenario projects a decrease in the use of biomass, but biomass is the main renewable energy source in the power sector. Energy is imported when demand is not met by domestic supply.
The APERC BAU scenario considers the Viet Nam National Energy Efficiency Program (VNEEP) phase one and two, the shift from traditional fuels to electrification, the National Technical Regulation on Energy Efficiency Buildings, and the Energy Efficiency Building Code technical standards. It does not include the recent VNEEP Phase three (MOIT, 2018) which would reduce energy demand (APERC, 2019b). In addition, the APERC BAU scenario was publish in 2019 and does not include any policies in 2020, such as Resolution 55, the extension of the solar feed-in-tariff, or solar auctions.
Current policy projections for energy non-CO2 emissions are based on US EPA (US EPA, 2019b) data.
Agriculture and waste emissions projections are based on the latest historical emissions in 2014 from the Third National Communication (MNRE, 2019), with a trend from the growth rates of the US EPA (US EPA, 2019b) non-CO2 data.
Projections for LULUCF (when included) are based on historical data for year 2014 the Third National Communication and projections from the updated NDC with interpolations between unreported years (MNRE, 2019; Viet Nam Government, 2020a).
Current policy industrial processes emissions are estimated by applying the markup share of industry emissions calculated from the last historical data point of total emissions excluding LULUCF and industrial processes. This is a conservative assumption, since the share of industry emissions has been increasing in the past.
We applied a novel method to estimate the COVID-19 related dip in greenhouse gas emissions in 2020 and the deployment through to 2030. The uncertainty surrounding the severity and length of the pandemic creates a new level of uncertainty for current and future greenhouse gas emissions. We first update the current policy projections using most recent projections, prepared before the pandemic (as above).
We then distil the emission intensity (GHG emissions/GDP) from this pre-pandemic scenario and apply to it most recent GDP projections that take into account the effect of the pandemic. The CAT used the GDP from APERC to estimate the pre-pandemic emissions intensity (APERC 2019a).
To capture a wide range, we compare several GDP projections to account for the pandemic. The CAT compared scenarios from the IMF, the World Bank, the Asian Development Bank, Viet Nam Institute for Economic and Policy Research, and government targets (ADB, 2020; IMF, 2020; Jennings, 2020; Onishi, 2020; VERP, 2020; World Bank, 2020). The CAT calculations are based on the largest range of scenarios available, and then choosing the maximum and minimum emissions out of all the scenarios to create a maximum and minimum range. The CAT applies the GDP growth rate of APERC to estimate GDP beyond the years that each scenario reported.
Global warming potentials
All figures in this assessment are consistent with the global warming potentials (GWPs) from the IPCC’s Fourth Assessment Report (AR4).