Iran (Islamic Republic of)

Historical emissions data (excluding LULUCF) for the period 1990-2021 are taken from PRIMAP (Gütschow & Pflüger, 2023). LULUCF data for the years 1994 and 2000 are taken from the UNFCCC emissions inventory, and the 2010 data is from the Third National Communication (Department of Environment of Iran, 2017).

Iran’s INDC is expressed as a percentage reduction below business-as-usual (BAU) emissions in 2030, but without specifying what the BAU scenario is. In our calculations we have used data points for the 2025 BAU provided in the Third National Communication released in 2017. For some sectors, the BAU data is not directly provided. For those sectors, we have used the ‘Mitigation Scenario’ emissions levels and have added to them the mitigation potentials given in the Third National Communication. We have excluded BAU emissions from LULUCF.

As the Third National Communication only provides BAU values for 2025, we have interpolated for values between 2010 and 2025. For the 2010 base year data, we take the values communicated in the Third National Communication.

The data in the Third National Communication assumes Global Warming Potential (GWP) values for non-CO₂ greenhouses gases from the IPCC’s Second Assessment Report (SAR). As the CAT uses GWP values from the Fourth Assessment Report (AR4), values from the Third National Communication have been converted from SAR to AR4 using a conversion factor based on PRIMAP data.

There is a high level of uncertainty regarding the emissions development in Iran. This is mostly due to uncertain economic growth projections linked to international economic sanctions. We capture this uncertainty by presenting a range for the current policy projections based on historical trends for agriculture and waste emissions, and GDP elasticity for energy and industry.

Iran’s economic situation is expected to have bigger impact on the industry and the energy sector, which is why we apply GDP elasticity combined with historical GDP data with a forecast to obtain a range. Emissions from the energy and industry sector are most susceptible to fluctuations in GDP growth. For the agriculture and waste sector, which are traditionally less impacted by the economic sanctions and overall economic landscape, we just apply 5-year historical trend from 2017-2021.

Lower end

For the emissions in the agriculture and waste sector, we apply a five-year trend based on historical data for 2017-2021. For the energy and industry sector emissions, the projections are based on the historical trends of GDP elasticity of the sectors’ GHG emissions combined with GDP growth estimates from IMF (IMF, 2023) .

Upper end

For the emissions in the agriculture and waste sector, we apply a five-year trend based on historical data for 2017-2021. For the energy and emissions sector emissions, the projections are based on historical trends of GDP elasticity of the sectors’ GHG emissions combined with historical GDP growth estimates from the World Bank (World Bank, 2023a).

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). Iran’s Third National Communication, from which much of our data is derived, uses SAR GWP values. Values from the Third National Communication have been converted from SAR to AR4 using a conversion factor based on PRIMAP data.