Three Reasons Why a COP28 Focus on Emissions—as Opposed to Fossil Fuel Phase Out—is Not Enough

As the COP28 climate talks enter their last days, countries dependent on fossil fuels are making the case that the final text should just focus on reducing emissions rather than also phasing out fossil fuels. This argument is often predicated on other mitigation approaches that may significantly offset emissions. The push back from the scientific community has been vigorous; here are three of the compelling arguments.

1. Abatement of fossil fuels by 2050 with carbon capture and storage (CCS) will likely be minimal—approximately 5 to 6% of fossil fuel energy.

As pointed out by Carbon Brief this week, CCS is a relatively immature technology and relying on it to abate a significant portion of emissions is “risky.” The International Energy Agency (IEA) Net Zero Emissions by 2050 Scenario (NZE) demonstrates that abatement only contributes a modest amount; about 6% of energy from fossil fuels could be covered by CCS by 2050. This is mirrored in the analysis from Climate Analytics, which shows that the median 1.5C pathway has only 5% of energy from fossil fuels abated with CCS. These scenarios demonstrate that even if CCS becomes viable, the amount of abatement is not significant enough to avoid the need to phase out fossil fuels.

2. Carbon dioxide removal (CDR) will likely be minimal. Even with ambitious deployment, it would take 80 years to remove the equivalent of 12.5 years of emissions at current levels. 

The nascent industry of carbon dioxide removal has prompted questions about how much it might scale to offset emissions. An expert consensus conducted by Grant et al. (2021) estimated the maximum feasible cumulative removal of BECCS, afforestation, and DACCS from 2020-2100 to be 740 gtCO2. This total is equivalent to only 12.5 years of greenhouse gas emissions at 2022 levels. Carbon removal may contribute modestly, but phasing out fossil fuels directly remains essential.

3. Failure to phase out fossil fuels would likely leave the world ~0.6°C short of its climate goal.

An ambitious global plan to address climate change that does not include phasing out fossil fuels would produce, in one simulated scenario, results that are 0.6°C short of the Paris Agreement temperature target.

Using our En-ROADS simulator, we asked: what if the world delivered on a plan emerging from COP28 that did not include phasing out fossil fuels? How much toward the 1.5 degree target might we get, given the best available science?

In the scenario, we apply all available mitigation options other than phasing out fossil fuels by increasing average global carbon price to $40, radically boosting renewables, accelerating energy efficiency and electrification, cutting deforestation and degradation, decreasing super-pollutants such as methane and f-gases, achieving gas/coal carbon capture and storage (CCS - funded by the carbon price), and investing in direct air capture with CCS (DACCS). In short, what if the world wins in everything but directly phasing out fossil fuels?

Our calculations in En-ROADS reveal that 2100 temperature would likely be 2.1°C, which is 0.6°C short of the 1.5°C Paris Agreement target (note - a scenario that succeeds is posted here).

Why does the gap remain? Primarily because it phases down, but not out, the burning of coal, oil, and gas, as one can see in the three graphs below.

En-ROADS is a simulator that our team here at Climate Interactive built in collaboration with the MIT Sloan Sustainability Initiative, using the best available science and tested against the suite of other Integrated Assessment Models and the World Energy Outlook of the International Energy Agency. All equations are listed in our Reference Guide.

Written by Andrew Jones, Ellie Johnston, and Joshua Loughman