How quickly does the world need to ‘phase down’ all fossil fuels?

February 23, 2023

India and China were widely criticised at COP26 in 2021 when they pushed to tone down the language on coal consumption that emerged from the climate summit.

As a result of this intervention from two highly coal-dependent nations, with the covert support of other key players, the final version of the Glasgow Climate Pact only called on nations to “phase down” rather than “phase out” unabated coal power.

The following year, at COP27, India’s proposal of a phase down of all fossil fuels was backed by more than 80 governments, but did not make it into the summit’s final text. This would have included oil and gas, which developed nations tend to rely on more than coal.

Such policy debates are strongly influenced by the Intergovernmental Panel on Climate Change’s (IPCC) 1.5C pathways. These are designed to minimise costs – usually without considering real-world social or political dynamics – and include much faster reductions in the use of coal than for oil and gas

While at a global level there is a logic to prioritising reductions in the most emissions-intensive fossil fuel, this raises questions of fairness.

In practice it means that much of the immediate burden of fossil fuel phaseout falls on large, developing countries that generate a lot of their electricity from coal.

Our new study in Nature Climate Change finds that, in 1.5C pathways assessed by the IPCC, coal power would have to be phased out in India, China and South Africa more than twice as fast as any historical power transition.

It also shows how moving the phaseout of coal onto a more politically-feasible trajectory would require faster reductions in oil and gas use, to keep 1.5C within reach. This would turn the spotlight onto accelerating action in developed, rather than developing, countries.

Fossil fuels and equity

As of 2019, coal provided 22% of power generation in high-income countries, compared to 54% in low- and middle-income countries, according to the most recent “world energy balances” published by the International Energy Agency (IEA).

The UK and Canada, which lead the Powering Past Coal Alliance (PPCA), a group established to encourage the phaseout of coal power, generated just 2% and 6% of their power from coal in 2019, respectively. Both have also rejected calls to phase out oil-and-gas production.

Meanwhile, coal’s share of power generation was 65% in China, 73% in India and 89% in South Africa.

The greater this share, the more power stations that would have to be replaced, increasing costs, stranded asset risks and the efforts needed to enable a just transition for coal communities. In addition, developing countries often have fewer financial resources to invest in the transition, as well as less historic responsibility for causing climate change.

Reflecting these issues, the PPCA has proposed a differentiated timeline, where the EU and other wealthy Organisation for Economic Co-operation and Development (OECD) members would phase out coal power by 2030 and other countries would do so by 2050.

However, such political realism does not generally appear in IPCC pathways.

In the median 1.5C pathway from the IPCC’s sixth assessment report, coal power drops globally by 87% by 2030 and by 96% by 2035, which would entail replacement of virtually the whole power fleet within a decade in coal-dependent developing countries.

By comparison, global gas power generation, 60% of which occurred in high-income countries in 2019, falls by just 14% by 2030 in the median pathway. Overall oil use falls by just 10% over the same period.

Phaseout and feasibility

To explore how feasible such a fast rate of coal phaseout is, we compare it with the fastest historical power transitions over the last 50 years, for all fuels and countries.

These transitions can be seen in the chart below. The dotted red line shows an “average” of all countries’ fastest transitions and the solid red line indicates the “world record” of the fastest transitions in the fastest countries, relative to size of the electricity system.

Countries’ fastest 10-year declines in a technology’s generation share, 1960-2018 for OECD countries and 1971-2017/18 for non-OECD countries. Source: Muttitt et al. (2023).

The historical period covered includes rapid policy changes, such as responses to the 1970s oil-price crisis, and political events, including wars, sanctions and the collapse of the Soviet Union. This suggests that the “world record” gives an indication of the fastest pace that could be feasible, even with major policy efforts.

The chart shows that transitions can be faster in smaller power systems, such as Malta’s conversion of its sole power station, Delimara, from heavy oil to gas between 2012 and 2017. In larger countries, transitions have generally been slower.

The countries closest to the world record pace of transition are all relatively wealthy, reinforcing the causal link between socioeconomic capacity and phaseout feasibility.

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Among poorer countries, the fastest transitions were generally driven by external events, and often came at a significant economic and social cost to those countries. For example, the collapse of Jamaica’s oil generation due to price rises in the late 2000s.

Record breaking

In our study, we use the TIAM-UCL global energy system model, which produces pathways that are comparable to those in IPCC reports, to look at individual countries’ coal phaseouts in a 1.5C pathway.

We find that coal power would have to be phased out in India, China and South Africa more than twice as fast as any of the historical power transitions we examined, relative to the size of the countries’ electricity systems.

This is shown in the chart below for the 10 largest coal-consuming countries, with those three countries far to the right of the “world record” line.

For the 10 largest coal-consuming countries, implied 2020-2030 reduction in coal share of generation on PPCA timeline, assuming linear decline either from 2020 to 2030 (OECD/EU) or from 2030 to 2050 (other countries). Source: Muttitt et al. (2023).

Phasing out coal use as quickly as possible will bring benefits to all countries, both by limiting warming and avoiding the severe health damage caused by air pollution from coal power plants.

However, if models suggest faster coal phaseouts than are likely to be politically, financially or socially possible, then pathways will act as weaker guides for where policy should go next. If governments follow the models’ guidance in all other respects but cannot achieve the coal part, warming will exceed 1.5C.

In comparison, the chart below shows the PPCA timeline, with coal generation reduced linearly to 2030 or 2050 for different groups of countries.

For the 10 largest coal-consuming countries, implied 2020-2030 reduction in coal share of generation on PPCA timeline, assuming linear decline either from 2020 to 2030 (OECD/EU) or from 2030 to 2050 (other countries). Source: Muttitt et al. (2023).

In this scenario, developing countries would still need to reduce their coal power generation by one-third by 2030, including by closing the most polluting plants. This is a faster decline than most governments in these nations are currently planning.

This differentiated pace would put several countries around the limit of historical transitions but not faster, suggesting that it is difficult but feasible.

Our study therefore shows one way that 1.5C pathways could better reflect contemporary realities, and in so doing distribute the efforts needed to get there in a more equitable way.

Some countries where coal currently has a lower share of power generation, such as Russia and Indonesia, may be able to move faster than the PPCA timeline. In the case of developing countries, this is likely to depend on access to climate finance.

Faster oil-and-gas phaseout

We also find that to achieve the 1.5C target with this PPCA pace for coal, developed countries would have to reduce emissions roughly 50% faster than in standard 1.5C scenarios. This has important consequences for oil and gas.

Even published pathways suggest oil-and-gas production must decrease to remain on track for limiting warming to 1.5C, rather than increasing as most countries plan.

However, when coal is phased out at the slower PPCA pace, oil and gas use must be reduced correspondingly faster.

This has a different impact on different countries. The figure below shows this, with the US’ cumulative oil production from 2020 to 2050 – indicated by the green bars in the chart on the right – 20% lower than in a default 1.5C pathway.

Change in cumulative 2020-50 regional gas (left) and oil (right) production, exajoules (EJ)  in a 1.5C pathway with coal phased out on the PPCA timeline, compared to default 1.5C pathway. The red dashed line shows % change in global production. Country and region codes are other (OTH), Europe except the former Soviet Union (EUR), USA, Mexico (MEX), Middle East (MEA), former Soviet Union (FSU), Central and South America (CSA), Australia (AUS) and Africa (AFR). Source: Muttitt et al. (2023).

Limiting climate change requires tackling emissions from all three fossil fuels. However, our research suggests that a greater focus on cutting oil-and-gas use would not only be more equitable, but also more realistic.

In practice, this would also mean greater decarbonisation efforts by the global north, even while all countries end coal power as quickly as possible.

Muttitt, G. et al. (2023) Socio-political feasibility of coal power phase-out and its role in mitigation pathways, Nature Climate Change, doi: 10.1038/s41558-022-01576-2 Unpaywalled, submitted version of the paper available here.

Teaser photo credit: By Hillebrand Steve, U.S. Fish and Wildlife Service –, Public Domain,

Greg Muttitt

Greg Muttitt is Co-Lead of Sustainable Energy Supplies at IISD. He has over 20 years of research experience on fossil fuels and climate change, focusing on the economics and politics of energy transitions. Before joining IISD, he was Research Director at Oil Change International and Co-Director at Platform. He is the author of the book Fuel on the Fire: Oil and Politics in Occupied Iraq (Random House, 2011). He holds a Bachelor of Arts in Physics & Philosophy and a Master of Science in energy economics. He lives in the United Kingdom

Tags: 1.5 degree C., phasing out fossil fuels