For historical data, GHG inventory data submitted to the UNFCCC accessed via the UNFCCC data portal was used for 1990 and 1994 (UNFCCC, 2019) and the National GHG Inventory Report from 2021 for data from 2000 to 2017 (Department of Environment Foresty and Fisheries, 2021), with linear interpolation between 1990–1994 and 1994–2000.
For the years 2018 and 2019, we use sectoral growth rates from PRIMAP historical emissions applied to the 2017 inventory data points for each sector (Gütschow et al., 2021).
Our CAT estimate for 2020 applies a sector-by-sector approach. For all energy sector emissions, we apply growth rates from the Global Carbon Budget for 2020 (Le Quéré et al., 2020). For industry sector emissions, we apply the 2020 GDP decrease from IMF (IMF, 2021). For the agriculture and waste sectors, we extrapolate the last 10-year average from historical emissions.
NDC and other targets
In its 2020 emission reduction pledge, South Africa aims for a 34% reduction below BAU by 2020 including LULUCF (Department of Environmental Affairs Republic of South Africa, 2011). The emission levels included under both the upper and lower bound of the targeted reductions are provided by the explanatory note. These targets are read directly off the peak, plateau and decline (PPD) emission trajectory graph (Department of Environmental Affairs Republic of South Africa, 2011).
LULUCF sector emissions are assumed to be included in the targets because the 1997 data point in the graph matches the historical emissions including LULUCF. To obtain the emissions level excluding LULUCF, it was assumed that the LULUCF sector continues to represent a small net carbon sink with the emission level in 2030 equivalent to the average emissions from this sector over 2007–2017 (annual emissions of -16 MtCO2e). The same approach was used for the quantification of the NDC target below.
In its updated NDC of 2021, South Africa provides an absolute emissions level in the target range of 398–510 MtCO2e including LULUCF and 350–420 MtCO2e including LULUCF for 2030 (Government of South Africa, 2021c). Assuming LULUCF remains at the average level over 2007–2017 (-16 MtCO2e), this NDC translates to an emissions level of 414-526 MtCO2e excluding LULUCF in 2025 and 366–436 MtCO2e excluding LULUCF in 2030.
It is unclear which GWP values have been used to calculate the target range of the updated NDC of 2021. The NDC states that its targets are based on the latest inventory report, which uses SAR values, and that the country will transition to using AR5 in 2024.
In its first NDC of 2016, South Africa’s target range was calculated using AR4 values. As the lower bound of the target range for 2025 is 398 MtCO2e (incl. LULUCF) in both the first NDC of 2016 and the updated NDC of 2021, we assume that South Africa has continued to use AR4 values for these figures, notwithstanding the values used in its inventory report. Furthermore, the comparison that “the upper end of the target range in 2025 has been reduced by 17%, and the upper end of the target range in 2030 has been reduced by 32%, and the lower range by 12%” (Government of South Africa, 2021c) points to comparing both target ranges in AR4.
Current policy projections
The current policy projections are based on a combination of the IEA World Energy Outlook (WEO) 2020 for CO2 emissions from fuel combustion (IEA, 2020) and non-CO2 emissions from the US EPA (2019). For CO2 process emissions, we used historical data from PRIMAP and assume a direct correlation to emissions from coal-fired power plants afterwards.
The WEO2020 Stated Policies Scenario for CO2 emissions from fuel combustion assumes full implementation of the 2019 Integrated Resource Plan with COVID-19 delay. For this reason, we do not further need to adjust installed energy capacities by 2030 as in past CAT assessments for South Africa using the Current Policies Scenario available in previous WEO reports.
The biofuels mandate has been furthermore quantified for informative purposes, however, it has not been included in the current policy projections due to the ongoing uncertainty of its implementation as of October 2021.
For non-CO2 emissions, US EPA (2019) projections until 2030 were used. For the CO2 process emissions, historical CO2 process emissions data from PRIMAP (Gütschow et al., 2021) was used to check the correlation to emissions from coal-fired power plants. For projections, CAT assumes that this correlation will continue, meaning that we assume CO2 process emissions to develop with the same trend as the CO2 emissions from coal fired power plants in our current policy projections.
We applied a novel method to estimate the COVID-19 related rebound in greenhouse gas emissions in two years after the 2020 and its impact until 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 current policy projections without adjustment for the rebound effect in 2021 and 2022 and applied it to the most recent GDP projections that account for the effect of the pandemic.
There exists a range of estimates from both national and international sources to estimate the potential impact of the pandemic on GDP (AfDB, 2021; IMF, 2021; SARB, 2021; World Bank, 2021). The IMF, World Bank and AfDB project GDP growth rates out to 2022, while South African Reserve Bank (SARB) projects GDP growth rates out to 2021.
We present the range of emissions scenarios in our graph based on maximum and minimum values for total GDP for each year using upper and lower range of GDP projections. In 2021, the upper is from the SARB (4.6% in 2021) and lower bound from the AfDB (3.0% in 2021). In 2022, the upper bound is from the IMF (3.1% in 2021, and 2.0% in 2022) and the lower bound from the AfDB (3.0% in 2021, and 1.6% in 2022).
We used the growth rates from our current policy scenario without the adjustment for a rebound effect to extend those projections to 2030.
Global Warming Potentials values
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). The ‘NDC and other targets’ section above outlines the uncertainties on GWP assumed for the updated NDC target range.