Geologically storing carbon is a key strategy for abating emissions from fossil fuels and durably removing carbon dioxide (CO2) from the atmosphere1,2. However, the storage potential is not unlimited3,4. Here we establish a prudent planetary limit of around 1,460 (1,290-2,710) Gt of CO2 storage through a risk-based, spatially explicit analysis of carbon storage in sedimentary basins. We show that only stringent near-term gross emissions reductions can lower the risk of breaching this limit before the year 2200. Fully using geologic storage for carbon removal caps the possible global temperature reduction to 0.7 °C (0.35-1.2 °C, including storage estimate and climate response uncertainty). The countries most robust to our risk assessment are current large-scale extractors of fossil resources. Treating carbon storage as a limited intergenerational resource has deep implications for national mitigation strategies and policy and requires making explicit decisions on priorities for storage use.
Competing interests: The authors declare no competing interests.
Figures
Fig. 1. Spatially explicit global carbon-storage potential…
Fig. 1. Spatially explicit global carbon-storage potential in sedimentary basins.
a , Onshore (brown) and…
Fig. 1. Spatially explicit global carbon-storage potential in sedimentary basins.
a, Onshore (brown) and offshore (blue) sedimentary basins, including national terrestrial and maritime borders (that is, EEZs). Basin colours vary according to technical carbon-storage potential (lighter) and the assessed prudent carbon-storage potential (darker). b, The North American continent, including all exclusion layers (Supplementary Table 1). The prudent limit is estimated by accounting for the full storage technical potential, removing all precautionary exclusion layers and summing up available carbon storage from the basins that remain (yellow dotted and light blue areas). PGA, peak ground acceleration. a,b, Sources: Esri, GEBCO, NOAA, National Geographic, DeLorme, HERE, Geonames.org and other contributors.
Fig. 2. Storage potential loss due to…
Fig. 2. Storage potential loss due to application of different risk layers.
a , The…
Fig. 2. Storage potential loss due to application of different risk layers.
a, The reduction in global storage potential after applying each subsequent exclusion layer (Supplementary Table 1). Assessed sensitivities form the lower and upper values of each uncertainty bar around the central estimate (Supplementary Table 2). b, The difference in total global potential before (left) and after (right) all exclusion layers are applied, resulting in the assessed planetary limit, including the central estimate and sensitivity cases. c, The full technical potential and final assessed potential in the central estimate by IPCC region (Supplementary Table 7). d,e, Our analysis is spatially explicit and globally consistent, allowing for country-level assessments of prudent storage potential in both offshore (d) and onshore (e) basins. f, Total storage before and after applying precautionary exclusion layers is heterogeneous across countries based on total storage magnitude loss (light colours to dark colours) and the percentage of technical potential lost (blue represents high absolute loss but low percentage loss, red represents high percentage loss but low absolute loss, and purple represents high loss along both axes). d–f, Sources: Esri, GEBCO, NOAA, National Geographic, DeLorme, HERE, Geonames.org and other contributors.
Fig. 3. Geologic carbon storage in scenarios…
Fig. 3. Geologic carbon storage in scenarios exceed the prudent planetary limit.
a , Schematic…
Fig. 3. Geologic carbon storage in scenarios exceed the prudent planetary limit.
a, Schematic highlighting the assumed use of carbon storage in mitigation strategies based on a future trajectory of net CO2 emissions and whether a temperature limit is achieved and maintained or whether a limit is exceeded after a peak and temperature drawdown occurs thereafter (top). Total yearly carbon storage is further differentiated by the strategy of fossil-fuel consumption pursued towards and after achieving net-zero CO2 emissions (middle and bottom). b, Cumulative stored carbon (scale of 1,000 GtCO2) distributed across scenarios until the time of net-zero CO2 emissions (left-side distributions) and until the last modelled year (2100, right-side distributions) against different thresholds: all non-excluded basins that currently have operational oil and gas facilities (purple), additional storage consistent with all remaining onshore basins (yellow), remaining offshore basins (red) and the prudent planetary limit (grey). In each distribution, the full range, median and interquartile lines are shown. c,d, The number of years it would take to reach each of the shown limits if storage levels were maintained after achieving net-zero CO2 emissions (c) or if storage levels were extrapolated beyond the year 2100 (d). The bars represent interquartile ranges and whiskers represent the 5th–95th percentile in c and d. Although we aggregate thresholds globally here, carbon storage is regionally deployed in integrated models with different regions exceeding thresholds at different points in time (Supplementary Figs. 8–12), with storage in the IPCC’s Asia region (including China and India) exceeding even our planetary limit threshold this century (Supplementary Fig. 8).
Fig. 4. Prudent carbon-storage potential is unequally…
Fig. 4. Prudent carbon-storage potential is unequally distributed among countries.
a , The relationship between…
Fig. 4. Prudent carbon-storage potential is unequally distributed among countries.
a, The relationship between responsibility for historical emissions (x axis) and the remaining storage potential (y axis) is shown, with the size of each point in the scatter plot being proportional to per capita gross domestic product (GDP). Countries in the top-right quadrant of the plot have relatively high historical responsibility for current warming levels and relatively high amounts of carbon storage available to support high-durability carbon removal, which in principle would lead to reducing future responsibility. Countries in the bottom-right quadrant have high responsibility, but limited capacity to store carbon domestically based on our analysis, implying the need to transport carbon elsewhere. Countries in the top-left quadrant have low responsibility but high remaining storage potential, and thus could in principle provide storage for appropriate financial transfers to countries without available resources under the Paris Agreement’s principle of common-but-differentiated responsibilities and respective capabilities to arrive at fairer outcomes aligned with its long-term temperature goal. Individual three-letter country codes are provided in Supplementary Table 5. b, The same plot as in a but using the emissions embedded in extracted fossil fuels by industrial carbon majors (https://carbonmajors.org/Downloads), showing which nations have the highest responsibility for historical fossil-fuel extraction—and thus who has reaped the largest revenues from sale of fossil resources—rather than territorial emissions.
Riahi, K. et al. in Climate Change 2022: Mitigation of Climate Change (eds Shukla, P. R. et al.) Ch. 3 (Cambridge Univ. Press, 2022); 10.1017/9781009157926.005.
Clarke, L. et al. in Climate Change 2022: Mitigation of Climate Change (eds Shukla, P. R. et al.) Ch. 6 (Cambridge Univ. Press, 2022); 10.1017/9781009157926.008.
Kearns, J. et al. Developing a consistent database for regional geologic CO2 storage capacity worldwide. Energy Procedia114, 4697–4709 (2017).
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DOI
Baines, S. et al. CO2Storage Resource Catalogue—Cycle 3 Report (Oil and Gas Climate Initiative, 2022).
Damon, et al. An integrated approach to quantifying uncertainties in the remaining carbon budget. Commun. Earth Environ.2, 7 (2021).
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DOI
