Indonesia

We use the historical data provided by the PRIMAP database for the period 2000-2019 and data reported to the UNFCCC in the Greenhouse gas inventory database for the period before 2000. There is a discrepancy between these two sources varies from 11% in 1990 to less than 1% in 2000. The absolute difference in 2000 is 2 MtCO2e - we have made no attempt to harmonise these data sources and use the PRIMAP data for the year 2000.

The CAT develops 2020 estimates either by sector, or by gas. For Indonesia we use the sector method, assuming that energy sector emissions follow the 2020 growth rate observed in the Global Carbon Budget (Le Quéré et al. 2020), industrial emissions follow the 2020 GDP dip reported by the IMF (IMF 2021b), and other sectors follow a five-year historical average.

To quantify the 2030 NDC target we use the BAU and the sectoral distribution from Indonesia’s NDC document – taken at face value and without harmonisation to historical data (Republic of Indonesia 2016).

The CAT takes the absolute emissions level excluding LULUCF by 2030 given in the official documents for the unconditional targets.

The NDC does not provide an absolute emissions level for the 2020 target. To quantify the 2020 pledge, the CAT assumes the sectoral contribution to emissions reduction from Indonesia’s Second Biennial Update Report (BUR), which implicitly assumes that the 2020 pledge and the NDC targets are based on the same BAU. The Second BUR shows that the LULUCF sector is responsible for around 80% of the emissions reduction in 2020.

We construct the range of current policy projections based on different assumptions of what might happen to the coal-heavy power sector in Indonesia in the future. The scenarios are based on the reference “Business-as-usual” scenario from the Asia Pacific Energy Research Centre (APERC), which "assumes current policies and trends continue" (APERC 2019), and on Indonesia’s 10-year electricity supply plan RUPTL 2019–2028 (Republic of Indonesia 2019).

According to APERC, the share of coal in power generation will decrease from 56% in 2016 to 55% in 2020, 50% in 2025 and then increase again to 51% in 2030. The APERC scenario is developed by an independent organisation and is used as an alternative development pathway since it is based on its own GDP and energy demand projections. The implementation of the RUPTL 2021-2030 leads to coal shares of 62% in 2025 and 64% in 2030.

Using emission factors from the IEA’s Current Policies Scenario for Southeast Asia, multiplied by the coal, oil, and gas shares for both TPES and electricity related emissions according to the APERC BAU scenario, gives the upper bound of emissions in our Current Policy Scenario for the energy sector, representing continued use of coal. The APERC BAU scenario foresees a 55 TWh increase coal generation from 190 TWh in 2025 to 245 TWh in 2030, in comparison to the RUPTL 2021–2030, which foresees a 65 TWh increase, from 220 TWh in 2025, to 285 TWh in 2030.

The total electricity demand forecast by the RUPTL 2021-2030 was revised downwards by almost 100 TWh in 2028 compared the previous RUPTL and is now lower than that in the APERC scenario.

We subsequently add non-energy and non-CO2 emission projections from the BUR2 and harmonise the resulting time series with energy-CO2 projections. The emissions levels are sensitive to the method of harmonisation. Thus, we apply two methods:

• Apply growth rates of the calculated scenarios to the last historical year;
• Adjust all future years by the difference of the calculated scenario and the inventory in the last available year (2016).

Both methods are included in the range presented for current policy projections.

Our planned policy scenario assumes that Indonesia will achieve renewable energy targets in both NEP and RPJMN 2020-2024. The trajectory reaching the NEP targets is constructed using APERC projections of total supply and demand as a baseline and adapting the relevant shares of renewables. It is assumed that the share of renewables in TPES will develop linearly from 2025 and 2050 between the targets for those years. The lower range, based on the RPJMN renewable installed capacity target, is created adjusting installed capacities and electricity generation from the RUPTL 2021-2030. We assume two scenarios for renewable deployment under different mixes: one that assumes more intermittent renewables (lower capacity factor) and another with more hydro and geothermal projects. The resulting emissions reductions are subtracted from the current policy scenario.

The impact of the medium-term development plan 2020-2024 targets in total primary energy supply is quantified using a first order estimative. We assumed that the renewable power generation shares, resulting from the uptake in renewable capacity in the target, that the input in TPES increases proportionally to share in electricity production, and that replacing fossil electricity reduces TPES by a factor one to two. Approximately 1 kWh from renewables instead of 1 kWh coal (produced with efficiency 1 to 3) reduces TPES by (-3+1) kWh.

This scenario is shown additionally to the range of current policy scenarios and the pledges based on the NDC’s BAU. Despite the continuing importance of coal in this scenario, it does result in substantially lower emissions than the current policy scenario range and would lead to Indonesia overachieving its conditional 2030 NDC target.

We applied a novel method to estimate the COVID-19 related dip in greenhouse gas emissions in 2021 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 distil the emission intensity (GHG emissions/GDP) from the historical data until 2020 and apply it to most recent GDP projections from 2021 that consider the effect of the pandemic. We have used a range of estimates to estimate the potential impact of the pandemic on GDP, including national projections by the Bank of Indonesia (IMF 2021c; 2021a; Asian Development Bank 2021; World Bank 2021). The national and international estimates only cover 2021 to 2026. We used the growth rates from our pre-COVID-19 current policy scenario to extend those projections to 2030.

The quantification of Indonesia’s current and planned policies focuses on energy-related CO2 emissions reductions. For scenarios that already consider the impact of COVID-19, such as the RUPTL 2021-2030, we do not adjust energy-related CO2 emissions, to avoid double-counting.

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).