January 18, 2024 by Aproop Dheeraj Ponnada, En-ROADS Climate Ambassador
December’s COP28 international climate conference in Dubai concluded with an agreement among the world’s nations to work toward “transitioning away” from fossil fuels. As expected, opinions remain divided on whether this agreement goes far enough to prevent the worst effects of climate change. With En-ROADS, we can test many of the underlying assumptions and the implied temperature rise, and if it does fall short, what policy shifts need to happen in 2024 and beyond.
The approved draft of the first global stocktake under the Paris Agreement featured nine clauses on emissions, with differing levels of specificity on associated pledges: based on available data, we can investigate one at a time.
COP28 Outcome Clause
|Quantified and time bound?
28 a) Tripling renewable energy capacity globally and doubling the global average annual rate of energy efficiency improvements by 2030
3x by 2030; 11 TW
4% by 2030
|28 b) Accelerating efforts towards the phase-down of unabated coal power
|Coal phase out
28 c) Accelerating efforts globally towards net zero emission energy systems, utilizing zero- and low-carbon fuels well before or by around mid-century
28 d) Transitioning away from fossil fuels in energy systems, in a just, orderly and equitable manner, accelerating action in this critical decade, so as to achieve net zero by 2050 in keeping with the science
|Oil & Gas phase out
28 e) Accelerating zero- and low-emission technologies, including, inter alia, renewables, nuclear, abatement and removal technologies such as carbon capture and utilization and storage, particularly in hard-to-abate sectors, and low-carbon hydrogen production
3x by 2050 (20+ country declaration)
|Technological carbon removal
28 f) Accelerating and substantially reducing non-carbon-dioxide emissions globally, including in particular methane emissions by 2030;
|Methane and other gases
28 g) Accelerating the reduction of emissions from road transport on a range of pathways, including through development of infrastructure and rapid deployment of zero and low-emission vehicles
28 h) Phasing out inefficient fossil fuel subsidies that do not address energy poverty or just transitions, as soon as possible
|Subsidies or carbon price
|100% by 2030
We start off with the most substantive and time-bound commitments in the stocktake: renewables, nuclear, energy efficiency, and methane:
1. Renewables and nuclear: “Tripling renewable energy capacity globally by 2030” and a commitment by over twenty countries to “Tripling nuclear energy capacity globally by 2050”
Ramping up of these energy sources can be simulated in En-ROADS with subsidies, with some “crowding out” dynamics creating competition between the two sources. Even with generous subsidies, we only see an uptake of 1.6x-1.8x in the energy mix, implying these actions are ambitious and push the bounds of possibility in En-ROADS considering the timeframes. The result is a 0.2°C reduction in temperature rise by 2100.
|1.6x (in energy, not installed capacity) by 2030 vs. 2023 levels
|1.8x (in energy, not installed capacity) by 2050 vs. 2023 levels
2. Energy efficiency: “Doubling the global average annual rate of energy efficiency improvements by 2030”
An unsung hero of the energy transition, energy efficiency is a high-leverage action that received much-deserved attention at COP. The pledge promises to increase the rate of energy efficiency (which can be estimated from the energy required per unit of GDP produced) to 4% by the end of the decade, up from the IEA’s estimate of 2% in 2022.
From an En-ROADS perspective, this is again an ambition that pushes the realm of possibility, as the large capital stock of fossil fuel-reliant assets and infrastructure require multiple decades to be replaced with more efficient technology to see an impact at the whole economy level. Nevertheless, applying a 5%/year energy efficiency improvement to new equipment in both transport and buildings and industry (representing an increase of 3-9x vs. business as usual) results in a respectable 0.4°C of temperature decrease. The effect on final energy consumption is quite pronounced as well, with efficiency leading to 55% lower energy consumption by the end of the century.
3. Methane: “Accelerating and substantially reducing non-carbon-dioxide emissions globally, including in particular methane emissions by 2030”
Following the Global Methane Pledge announced in 2021 at COP26, attention toward methane emissions grew at COP28 with a focus on reducing methane emitted during oil and gas production. Assuming the pledges made by the industry can be met to reduce methane emissions in this sector, replicating such an achievement in agriculture, industry, and waste, and including N2O and F-gases could drive down temperature a further 0.3°C.
The remaining proposed clauses can be classified into two broad categories of actions from a technology lens (with broader economic levers like subsidies or carbon taxes affecting the rate of change):
4. Carbon dioxide capture (CCS) and carbon dioxide removal (CDR): “Accelerating zero- and low-emission technologies, including, inter alia, renewables, nuclear, abatement and removal technologies such as carbon capture and utilization and storage”
CDR/CCS has served as a contentious issue historically, with two opposing viewpoints:
As with most arguments, the truth lies somewhere in the middle, with CDR likely playing some role in the future. 1.5°C scenarios modeled in the IPCC’s Assessment Report 6 (2022) deploy a cumulative median removal of 364-573 Gt CO2 by 2100 (depending on level of overshoot) across BECCS, enhanced weathering, and DACCS solutions.
We can conservatively assume a mid-range figure of around 470 Gt CO2 as a “speed limit” for non-land use CDR in En-ROADS, contributing to a further 0.1°C of temperature reduction. It is worth mentioning that En-ROADS provides a wider range of technological solutions than the IPCC included in the table above. We will revisit CO2 removals through land use later in the analysis.
5. Substitution solutions: From a whole-system emissions perspective, policies to phase out fossil fuels or policies to substitute them with biofuels, hydrogen, or electricity can produce similar results. The key challenge in both cases is to make interventions in a managed way to avoid price shocks.
Electrification: “Accelerating the reduction of emissions from road transport on a range of pathways, including through development of infrastructure and rapid deployment of zero and low-emission vehicles” and “Accelerating zero- and low-emission technologies, particularly in hard-to-abate sectors”
Simulating aggressive subsidies to boost the purchase of electric vehicles and electric equipment in buildings and industry would add to the already favorable conditions in this scenario for electrification through low-cost renewables and nuclear.
Biofuels and hydrogen: “Accelerating efforts globally towards net zero emission energy systems, utilizing zero- and low-carbon fuels well before or by around mid-century” and “Accelerating zero- and low-emission technologies, including low-carbon hydrogen”
Generous subsidies for bioenergy (from crops and waste), and hydrogen (modeled in this scenario by approximating hydrogen use as a breakthrough in energy storage for renewables) would have little impact on the temperature in this scenario, given the significant momentum to electrify most fuel uses, as well as the constraints on the amount of land available for bioenergy crops.
Note: En-ROADS does not currently model hydrogen specifically. The Climate Interactive team is releasing updates to En-ROADS in the next few months that will enable users to test the impact of hydrogen in scenarios.
6. Phasing out fossil fuels:
Phasing out subsidies: “Phasing out inefficient fossil fuel subsidies that do not address energy poverty or just transitions, as soon as possible”
The International Monetary Fund estimated explicit fossil fuel subsidies in 2022 to total around $1.3 trillion. A negative subsidy (i.e., a tax) of $45/tce on coal, $40/boe on oil, and $2.2/Mcf on natural gas would amount to $1.3 trillion in 2030.
Coal phase out: “Accelerating efforts towards the phase-down of unabated coal power”
A commitment to stop building new coal infrastructure by 60% (accounting for large developing countries relying on coal through the long term) would contribute a further reduction, avoiding a “fat tail” in demand due to infrastructure lifetimes.
7. Deforestation: “Enhanced efforts towards halting and reversing deforestation and forest degradation by 2030”
An ambitious commitment to end deforestation and mature forest degradation by the end of the decade would result in a further 0.1°C temperature reduction, in addition to mitigating biodiversity loss. The plausibility of such a scenario comes into question however, given the dramatic and abrupt scale of deforestation activity phase out needed, as evident from the left-hand graph below.
On one hand, the pledges made at COP28 still point towards a below 2°C scenario, however they fall short of the Paris Agreement ambition to hold global average temperature increase ”well below 2°C above preindustrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels.” Some additional actions that can be explored to achieve this are as follows.
8. Oil & gas phase out:
The residual emissions in the system directly point to oil and gas as the main drivers of energy sector CO2 emissions at this point. A commitment to stop building new oil & gas infrastructure would rapidly shorten the lifespan of residual emission sources and lead to a 1.7°C scenario.
9. More ambition on methane and other greenhouse gases:
Deeper cuts in methane and other greenhouse gases to the tune of 75% over the next few decades would reduce a further 0.1°C of warming.
10. Afforestation: Planting 400 million hectares of forests (nearly half the size of the United States) would be necessary to facilitate an additional 170 Gt of CO2 removal by end of the century.
Whilst this set of additional measures brings the scenario down to 1.5°C, it sheds light on the scale of the challenge in still keeping the goal alive, with rapid and unprecedented ambition on a range of levers. En-ROADS shows us that it’s possible—now we need to make it happen.
Accordingly, the En-ROADS version of the global stocktake commitments in line with a 1.5°C scenario reads as follows:
Driving responsible and efficient use of energy: Improving energy efficiency through measures including electrified transport, public transport, higher standards in household appliances, and improved industrial processes.
Managed phase out of residual fossil fuels: A two-pronged approach needs to be taken towards coal, oil, and gas, effective immediately:
Targeted action to eliminate all fossil fuel subsidies: Applying a negative subsidy of $45/tce coal, $40/boe oil, and $2.2/Mcf gas. The money freed up could be redirected to financing a just transition for the energy-poor.
Cleaning up the grid: Rapid scale up of non-fossil electricity (wind, solar, hydro, geothermal, and nuclear) from about 40% in the power generation mix to 50% by 2030, and 90% by 2040, resulting in an average global grid emissions intensity of <45 kg CO2/MWh before 2040.
Ensuring responsible stewardship of our forests: Achieving a net growth in forest areas from about 3.6 billion hectares presently to 4 billion hectares by 2060 by:
Limiting CDR to only essential reduction of residual emissions: Recognizing the need for carbon removals to reverse overshoot of temperatures beyond 1.5°C, deploying around 475 Gt of technological carbon removal, peaking at 7-8 Gt CO2/year of removals by 2050.
Using biofuels and hydrogen only as energy security measures: Due to limited incremental impact on temperature, and the significant time lag in scaling up supply chains for new fuels, these solutions may serve to stabilize price shocks rather than direct emission abatement approaches.
Reducing methane and other greenhouse gas emissions: Whole-heartedly adopting best practices across agriculture, industry, energy, and waste sectors to curtail emissions of methane, N2O, and F-gases.