“Unextractable oil, fossil methane gas and coal reserves are estimated as the percentage of the 2018 reserve base that is not extracted to achieve a 50% probability of keeping the global temperature increase to 1.5 °C. We estimate this to be 58% for oil, 59% for fossil methane gas and 89% for coal in 2050. This means that very high shares of reserves considered economic today would not be extracted under a global 1.5 °C target.”
The paper, published in September 2021 on Nature from Dan Welsby, James Price, Steve Pye and Paul Ekins, estimate the amount of the presently proven reserves and resources which should not be extracted in order to have 50% of probability of limiting warming to 1.5 °C. This means setting the amount of CO2 emissions possible until 2100 to 580 GtCO2.
The study also estimates that oil and gas production must decline by 3 per cent each year until 2050.
The largest reserve holders, such as the Middle East (MEA) (for oil and fossil methane gas) and Russia and other former Soviet states (FSU) (for fossil methane gas) have the strongest influence on the global picture, and therefore have estimates close to or marginally above the global average. For oil, Canada has much higher unextractable estimates than in other regions, at 83%. This includes 84% of the 49 billion barrels (Gb) of Canadian oil sands we estimate as proven reserves. By contrast, the FSU region has a relatively low unextractable share of total oil reserves (38% in 2050), reflecting their cost-effectiveness.
Moreover, the paper the outlook to 2050 for the five largest oil-and fossil methane gas-producing regions. The outlook is one of decline, with 2020 marking both global peak oil and fossil methane gas production, with decline thereafter to 2050 of 2.8% and 3.2%, respectively.
Finally, the authors highlight how the picture painted by their scenarios for the global fossil fuel industry is very probably an underestimate of what is required, since they use a carbon budget associated with a 50% probability of limiting warming to 1.5 °C, which does not consider uncertainties around, for example, Earth system feedbacks. Therefore, they say, more carbon needs to stay in the ground.
Full article at: https://www.nature.com/articles/s41586-021-03821-8
Top, Maps of the percentage of unextractable reserves of oil, fossil methane gas and coal. Bottom, absolute amount of each fossil fuel reserve that must remain unextracted.
Source: Welsby, D., Price, J., Pye, S. et al. Unextractable fossil fuels in a 1.5 °C world. Nature 597, 230–234 (2021). https://doi.org/10.1038/s41586-021-03821-8
“Central to pushing this transition forwards will be the domestic policy measures required to both restrict production and reduce demand Increasing attention is being focused on supply-side policies that can complement carbon pricing and regulatory instruments that focus on demand. Such policies act to curtail the extraction of fossil fuels and can include subsidy removal, production taxes, penalties for regulatory non-compliance and bans on new exploration and production. The development of international initiatives, such as the proposed non-proliferation treaty on fossil fuels, is also key as they could serve to foster global action, as could existing frameworks such as the United Nations Framework Convention on Climate Change”