The Paris Agreement and NDCs: are the national mitigation targets sufficient to stay below the 1.5-2°C limit?

Short introduction on Zambia’s emissions

Although CO₂ is the driving force behind the temperature changes, other gases such as methane (CH₄) also contribute their share to global warming, for example through the exploitation of gas fields, and emissions by livestock. While methane is emitted much less than CO₂ on a global scale, it is a much stronger greenhouse gas (GHG). Scientists estimated the relative strength of the important Kyoto greenhouse gases so that we can convert all emissions to an equivalent of CO₂ emissions. For example, the emission of one ton of methane has approximately the warming effect of 25 tons of CO₂. The factor of 25 reflects the climate forcing on a 100-year time horizon, following the Global Warming Potential presented in the IPCC Fourth Assessment Report (AR4).

With greenhouse gas emissions of approximately the equivalent of 41.1 mega tonnes of CO₂ (Mt CO₂eq), Zambia contributed 0.086% to the global greenhouse gas emissions of 2017 (rank 95 - incl. EU27 on rank 3). All emissions estimates exclude emissions and absorption from land, which result from activities such as cutting down or planting of forests (Land Use, Land-Use Change and Forestry: LULUCF). Emissions from bunker fuels (international aviation and shipping) were also excluded, as they are not accounted for in national totals.

For 2030, Zambia’s global contribution to greenhouse gas emissions is projected to stay at a similar level of approximately 0.10% (56.8 mega tonnes of CO₂ equivalent / rank 89 - incl. EU27 on rank 4). The emissions projections for Zambia were derived by downscaling the Shared Socio-Economic Pathways’ (SSPs) “Middle-of-the-Road” baseline marker scenario SSP2. These pathways describe certain narratives of socio-economic developments and were, i.a., used to derive greenhouse gas emissions scenarios that correspond to these developments. SSP2 is a narrative with little shifts in socio-economic patterns compared to historical ones, and is connected to medium socio-economic challenges for both climate mitigation and adaptation. While different models were used for each storyline, per SSP (SSPs1-5) one model was chosen as representative “marker scenario”. As the emissions projections are not readily available on country-level, but national estimates are important, the pathways were downscaled in the aftermath. In 2017, Zambia represented 0.22% of the global population. Its Gross Domestic Product (GDP) in 2017 were 0.058% of the global GDP.

Looking at the highest contributing emissions sectors and gases separately, we find that in 2017 the highest contributing emissions sectors were Agriculture and Energy (67.7% and 21.0%). Amongst the greenhouse gases that are considered in the Kyoto Protocol, the strongest contributor with 47.8% was CH₄. This was followed by N₂O emissions, with a share of 40.4%. When not considering the sectors and gases independently, but the sector-gas combinations instead, Agriculture N₂O and Agriculture CH₄ (38.2% and 29.5%) represented the largest emissions in 2017.

Greenhouse gas mitigation and Nationally Determined Contribution (NDC)

In 2015, the majority of countries agreed to the Paris Agreement (PA), with the goal of “Holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels, recognizing that this would significantly reduce the risks and impacts of climate change” (Article 2.1.a). Countries stated their pledges and targets towards achieving the PA’s goals in their Nationally Determined Contributions (NDCs). With Article 4.4 of the Paris Agreement, Parties decided that “Developed country Parties should continue taking the lead by undertaking economy-wide absolute emission reduction targets. Developing country Parties should continue enhancing their mitigation efforts, and are encouraged to move over time towards economy-wide emission reduction or limitation targets in the light of different national circumstances.”

In its updated 2020 NDC, the country communicates that “This NDC is submitted with a conditional pledge of reducing Greenhouse Gas (GHG) emissions by 25% (20,000 Gg CO₂ eq. [SAR]) by 2030 against a base year of 2010 under the BAU scenario with levels of international support prevailing in 2015 or by 47% (38,000 Gg CO₂ eq. [SAR]) with substantial international support.” (NDC, p. 4, GWP: p. 15). Further it specifies that “By this submission Zambia enhances its NDC by broadening the scope of sectors under mitigation by adding transport, liquid waste and coal (production, transportation and consumption) and by elaborating the adaptation component of the NDC by developing indicators that will enable the country track progress on building resilience in both the human and physical systems and on adaptation actions.” (NDC, p. 1). Both reduction levels are contingent on international support.

From the relative and absolute reduction level, we estimate the underlying projected BAU emissions to be about 81 MtCO₂eq SAR in 2030. The projection reference year is 2010 (NDC, p. 2). Absolute target emissions are calculated as 42.9-60.0 MtCO₂eq SAR (47 or 25% reduction). The availability of national estimates of emissions mitigation targets and pathways in line with countries’ NDCs is of great importance when, e.g., aggregating to global emissions to then derive, i.a., the resulting end-of-century warming levels.

In its contribution, “Zambia is now considering all sectors and categories as potential contributors to its mitigation efforts.” (NDC, p. 5). All main IPCC sectors are explicitly listed in the NDC “Sectors: Energy, industrial processes and product use, Agriculture Forestry and Other Land Use (AFOLU), and waste.” (NDC, p. 4). However, the country also specifies that “The reference indicator will be quantified based on national total greenhouse gas (GHG) emissions, except AFOLU in the base year 2010.” (NDC, p. 2). Nevertheless, we assume AFOLU to also be included, as additionally the country notes that “Zambia used IPCC 2006 guidelines for both Third National Communication and BUR. All the categories were included in the baseline emissions in the INDC” (NDC, p. 14), and in the section “Sectors, gases, categories and pools covered by the nationally determined contribution” it mentions that “For the AFOLU sector, emissions and removals the following reporting categories are included: forest land, cropland, grassland, and wetland (wetland remaining wetland only from 2026), including land use changes between the categories, and between these categories and settlements and other land. The five carbon pools above-ground biomass, below-ground biomass, litter, dead wood and soil organic matters are included. In addition, the carbon pool harvested wood products is included.” Furthermore, information on emissions accounting for LULUCF is included in the NDC (NDC, p. 15-16), and for the “Forestry and Land Use” component of the NDC, “Major mitigation themes are: 1) reduction in deforestation; 2) increase in afforestation and reforestation; 3) improved forest management; 4) careful agro-forestry practice.” (NDC, p. 6).

From the Kyoto GHG basket, all gases besides NF₃ are listed as covered (NDC, p. 4). For NF₃, e.g., PRIMAP-hist v2.1 has no historical emissions data available for Zambia. NF₃ has only been added to the Kyoto GHG basket for the Kyoto Protocol’s second period. It is merely reported by few countries and contributed less than 0.01% to global Kyoto GHG emissions in 2017 (exclLU and exclBF, based on PRIMAP-hist v2.1 HISTCR, in AR4, with its share being influenced by the few available data). In total, our assessment of covered sectors and gases results in an estimated 100% of 2017’ emissions being targeted by the NDC (based on PRIMAP-hist v2.1 HISTCR exclLU, in AR4).

Zambia additionally notes in its NDC, that “The national total GHG emissions in 2010 may be updated and recalculated due to continuous methodological improvements. Information on updates made will be included in the relevant reporting under the UNFCCC, and from 2024 onwards in the Biennial Transparency Reports.” (NDC, p. 3). Furthermore, “Final accounting towards the target, that will take place in 2032, may depend resource availability. Zambia does not rule out the possibility of using market based mechanisms in meeting emission reduction target.” (NDC, p. 14), and also states that “Zambia intends to use voluntary cooperation under Article 6 of the Paris Agreement to fulfil part of its target.” (NDC, p. 17).

The NDC-assessment is based on Zambia’s NDC submitted to the UNFCCC in March 2020.

The Figure below provides additional information, regarding both the baseline emissions used in our assessment and the quantified mitigated pathways for Zambia.

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Baseline emissions and mitigated emissions pathways based on the country’s Nationally Determined Contribution. In terms of national emissions, we look at the SSP2 baseline marker scenario, and the emissions of all IPCC sectors. Contributions from LULUCF are excluded (exclLU), and the emissions are based on GWPs from AR4. The left panel (a) shows the baseline emissions, indicating the contributions of the Kyoto Greenhouse Gases CO₂, CH₄, N₂O, and the basket of F-gases to the national emissions. If we could extract baseline data exclLU from the NDC, you can see their values as black squares (converted from GWP SAR to AR4 if needed). In the right panel (b), the quantified mitigated emissions pathways are shown, based on information from the country’s NDC and also on non-NDC emissions baselines, per target conditionality and range (marked un-/conditional best/worst). Even though not all countries have targets with different conditionalities or ranges, we need assumptions for all four cases to build one global pathway per conditionality plus range combination and to derive corresponding temperature estimates. Therefore, we indicate these four pathways here. Per combination, we performed several quantifications with differing assumptions and show the median and the minimal and maximal pathways here. Additionally, if we could quantify the targets based on data extracted purely from the NDC - or if the targets were directly given in absolute emissions, these targets are shown as squares (in the GWP originally given in the NDC).

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FIG 1

Data sources and further information

• Historical emissions: PRIMAP-hist v2.1 (Guetschow et al., 2016, 2019).
• Historical socio-economic data: PRIMAP-hist Socio-Eco v2.1 (Guetschow et al., 2019).
• Projected emissions and socio-economic data: downscaled SSPs (Guetschow et al., 2020, 2020).
• NDC quantifications: NDCmitiQ (Guenther et al., 2020, 2021).
• GDP is given in purchasing power parity (PPP).
• Main emissions sectors (Intergovernmental Panel on Climate Change, IPCC): Energy, Industrial Processes and Product Use (IPPU), Agriculture and LULUCF (Land Use, Land-Use Change and Forestry), also named AFOLU (Agriculture, Forestry and Other Land Use), and Waste.
• Kyoto GHG: basket of several GHGs, namely carbon dioxide (CO₂), Methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulphur hexafluoride (SF₆), and since the second Kyoto Protocol period (2013-20) additionally nitrogen fluoride (NF₃).
• Global Warming Potentials (GWPs): GHGs have very different warming potentials. To make them comparable and for aggregation purposes, GWPs are used (how much energy will 1 ton of a certain gas absorb over a defined period of time, relative to the same mass of CO₂?).