Nigeria’s NDC update provided revised historical emissions for 2010 and 2018 using AR5 global warming potentials (GWPs) (Federal Government of Nigeria, 2021). We converted 2018 emissions to AR4 using sector-by-sector gas shares from PRIMAP for the same year (Gütschow & Pflüger, 2022). Land use was excluded using the AFOLU sub-sector breakdown provided for 2018 in the NDC update.
The NDC update notes that the significant jump observed in emissions between 2017 and 2018 depicted in Nigeria’s sector-by-sector bar chart of historical emissions is due to differences in data sources for the energy sector for those years.
We have used PRIMAP sector growth rates to extend the historical time series, both back to 1990 and forwards to 2021, rather than the data provided in the NDC until 2010, as it is likely a more accurate depiction of the year over year change.
There is a significant difference between the emissions reported in the NDC and PRIMAP estimates (around 100Mt higher in PRIMAP than the NDC in recent years), largely due to the differences in estimates for energy sector emissions. We have continued to base our estimates around governments sources for consistency with the national dialog, but strongly urge the government to focus on its inventory and trying to understand the differences between its figures and international sources of data.
NDC and other targets
Nigeria’s NDC update uses global warming potentials (GWP) values from the IPCC’s fifth assessment report (AR5). CAT uses GWP values from the fourth assessment report (AR4) to ensure comparability across countries.
The NDC provides a sector-by-sector breakdown of emissions in 2018 and 2030. We have converted from AR5 to AR4 using the gas-by-gas breakdown for each sector from PRIMAP for the year 2018. We have not converted HFCs as we do not have information on individual gases; however, these gases represent only 1 MtCO2e in 2018.
The final NDC update provides LULUCF emissions for 2018 and AFOLU emissions for the 2030 BAU. To estimate LULUCF emissions in the 2030 BAU, we applied the same ratio of LULUCF/AFOLU as in 2018.
The update provides no information on the extent to which Nigeria intends to rely on reducing land sector emissions to meet its NDC targets. However, the update does estimate the potential of nature-based solutions as about 115 MtCO2e. Of these solutions, the top three are identified as agroforestry, improved forest management, and forest restoration, making up about 89 MtCO2e of the total potential. We use the 89 MtCO2e estimate as the upper bound of our estimate for the contribution of the land sector in meeting Nigeria’s conditional target and a proportional share of the 89 MtCO2e estimate for the unconditional target. We assume this estimate is all CO2 and thus there is no need to convert from AR5 values.
For the lower bound, we assume the land sector contributes an equal share as remaining sectors for both targets.
The Third National Communication identified significant abatement potential in the land sector, though its estimation of land sector emissions may have been higher than what is now reported in the final NDC update. Overall, there is significant uncertainty in the land sector emissions and our estimates are best guesses based on the available data.
Net zero target
Nigeria has not provided detailed information about how it intends to reach its net zero target.
We have quantified the target for the purposes of our ‘Optimistic’ global temperature estimate. We assume emissions (excluding LULUCF) are reduced 50% below 2018 levels by 2050 in line with Nigeria’s long-term vision and assume the country reaches 0 emissions in 2070 (DCC, 2021). The long-term vision does not specify the role that LULUCF will play in meeting this target, so we assume the 50% target applies equally to LULUCF and non-LULUCF emissions.
Analysis of the NDC covers the 4 gases included in Nigeria’s NDC target. Our assessment of historic emissions and current policies also includes PFCs and SF6, which were around 1 MtCO2e in 2018.
Current policy projections
We derive our current policy projections from a combination of the Stated Policies Scenario from IEA’s Africa Energy Outlook 2019 and the Planned Energy Scenario from IRENA’s 2023 Renewable Energy Roadmap Nigeria for energy emissions and from the US EPA for agriculture and waste emissions, and the US EPA and Energy Transition Plan for industry (Federal Republic of Nigeria, 2022; IEA, 2019; IRENA, 2023b; US EPA, 2019). In general, the IEA Africa Energy Outlook 2019 report does not specify which of the policies have been included in the stated policies scenario. The IEA’s Africa Energy Outlook 2022 did not contain updated country level data, hence why we have continued to use the 2019 report (IEA, 2022a).
The IEA’s Stated Policies Scenario was used to derive our lower bound projections for energy CO2 emissions. This scenario assumes development of coal-fired generation in Nigeria; however, all recent coal plant projects have either been cancelled or shelved. Therefore, we have adjusted our lower bound to assume the coal generation in Stated Policies Scenario is met with renewable energy, in line with national targets. For the upper bound, IRENA’s Planned Energy Scenario was used for energy CO2 emissions. In our lower and upper bound, projections for energy CH4 and N2O are extended using recent historical trends.
We have adjusted the energy emission projections from the IEA’s Africa Energy Outlook 2019 to take into consideration the impact of the pandemic. We distilled the emission intensity (GHG emissions/GDP) from the pre-pandemic IEA scenario starting in 2019. This emission intensity estimate was then applied to the most recent GDP projections from the IMF for Nigeria that take into account the effect of the pandemic (IMF, 2022). As these estimates only cover 2022 to 2027, we used the average GDP growth projected by the IMF for 2022-2027 to extend the projections until 2035. Results were then harmonised to our 2021 estimate (see Historical emissions above). The IRENA Planned Energy Scenario already considers the impact of COVID-19.
Planned policy projections
Our planned policy scenario is based on the Energy Transition Plan (ETP) which Nigeria released in August 2022 and for which it will need international support to implement (Federal Republic of Nigeria, 2022).
We use the ETP growth rates for energy and industry emissions and the US EPA projection growth rates as proxies for the agriculture and waste sectors.
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.