To analyse the commitment of countries to the adoption of geological CO2 storage (CGS), including fossil CCS and subsurface CDR, we focused on the role of CGS outlined in country level Long-Term Low-Emission Development Strategies (LT-LEDS). We did not consider the Nationally Determined Contributions (NDCs) due to their short-term nature (projected for 2030, in some cases lasting less than a decade), which is inadequate for the scale-up of fossil CCS or subsurface CDR. 68 LT-LEDS were submitted to the UNFCCC prior to January 1st 2024, but we discard the LT-LEDS submission on behalf of the EU because, in accordance with Article 4.19 of the Paris Agreement, individual member states of the EU submit their own strategies.
4.1 Analysing and classifying country-level commitment to CGS in LT-LEDS
The LT-LEDS documents were written either in English, Spanish, or French. To identify reference to CGS and nature-based removals within the LT-LEDS reports we searched for the full range of possible ways to refer to the CGS and its various components and nature-based removals in the different languages. Based on this search, we categorised countries according to their intended commitment to implementing CGS. The categories included: Yes - countries with a firm intention to implement CGS as an explicit part of their emission reduction strategies; Possible commitment - countries that included CGS in some emissions reductions pathways or mentioned it as a possible technology; No - countries that firmly rejected CGS for their emissions reductions strategies; Unspecified - countries that made no mention of CGS at all.
The CGS search terms we used were: CCS, CCUS, CCU, CAC, CUAC, CSC, CSU, use, usage, utilization, Carbon Capture, Carbon Storage, Carbon removal, CDR, CO2 storage, CO2 capture, negative, removal, captage, stockage, de carbone, captura/almacenamiento de carbono, captura y secuestro, sequestration, stor*, sequest*, remov*, capt*, almac*, stock*.
For CDR through nature-based removals, we used the following search terms: LULUCF, land use, land use change, forest, forestry, afforestation, reforestation, AFOLU, utilisation des terres, forêt, foresterie, boisement, reboisement, uso de la tierra, bosque, silvicultura, forestación, reforestación.
Where possible, we identify specific CGS applications in the LT-LEDs. In some cases the terminology used can make this difficult: for example, reference to use of CCS for negative emissions could be inferred to mean DACCS or BECCS, in which case we infer commitment to subsurface CDR but not to specific technologies.
4.2 Classifying country income
We started with the 197 countries that are signatories to the Paris Agreement as of January 1, 202337. These countries have been further subdivided based on their per capita income level according to the income classification established by the World Bank38: High income country, HIC (US$13,205 or more); Upper-middle income country, UMIC (between US$4,256 and US$13,205); Lower-middle income country, LMIC, (between US$1,086 and US$4,255); Low income country, LIC (US$1,085 or less). In total, 57 countries (31%) are classified as high income, 51 (27%) as upper middle, 53 (28%) as lower-middle and 25 (13%) as low income countries. Eleven (6%) of the countries signatory to the Paris Agreement lack an income level classification.
Of the 197 countries analysed 186 (94%) have an income status assigned by the World Bank.
4.3 Classifying historical oil and gas production
To determine the historical level of oil and gas (HOG) production, we have summed up the cumulative production of oil and gas (in TWh) from 1900 to 2019, available in Our World in Data as of January 1, 202339. In order to subdivide the countries, we have set a threshold at 1000 TWh of cumulative production, where those with values above 1000 TWh are considered "High", and those below 1000 TWh are considered "Low". In total, 59 countries (30%) are considered “High” historical oil and gas producers, 54 (27%) are “Low” producers. A further 84 countries (43%) lack historical oil and gas production data.
Of the 197 countries analysed, 113 (57%) have HOGP data.
4.4 Classifying CO 2 Storage Index
To determine the readiness to implement CGS, we used the CCS Storage Indicator (CSI), a classification developed by the Global CCS Institute (GCCSI) with the intention to provide a unified, quantified assessment that enables harmonised tracking of country-level CCS development and deployment. To calculate CSI, the GCCSI considers technical aspects required for CGS within a country’s borders including the geology, the maturity of storage assessments and track record of storage projects.
Of the 197 total countries analysed, 75 (38%) have a CSI, ranging from 0 to 98. Data sources include GCCSI40 supplemented by more recent information in the CO2RE data portal (https://co2re.co/). Of these countries, 51 (68%) have submitted an LT-LED.