Recent analysis about announcements made at COP26 showed the world could be on track for a 50% chance to limit end-of-century warming to 1.8°C. So why do we need to be cautious?

These reductions in 2100 temperature estimates are largely the result of announced net zero targets for 2050 and beyond. This still leaves an enormous emissions gap in 2030 and is not enough to keep 1.5°C in reach.

In a recently posted analysis, the International Energy Agency (IEA) has estimated that current commitments, many of which are not included in law or official national documents, would give the world a 50% chance of limiting end-of-century warming to 1.8°C, with a one-in-four chance of exceeding 2°C. This is not a Paris Agreement compatible pathway.

Because global warming is tied directly to the total sum of all CO2 emissions, each year of delayed action to 2030 will limit our ability to keep warming to 1.5°C by 2100. The IEA’s Announced Pledges Scenario, mapped in red in the graph below, exceeds the 2030 range of emission levels in 1.5°C compatible pathways by a wide margin, and continues to do so through to mid-century.

Between today and 2050, the IEA 1.8°C pathway emits on average 350 Gt more CO2 than what is observed in IPCC 1.5°C pathways. This would result in a more than 25% chance of a peak warming level above 2°C. This is not compatible with the long-term temperature goal of the Paris Agreement of “holding the increase in the global average temperature to well below 2°C… and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels”.

Delayed action observed in the pledge scenario leads to significant and avoidable warming beyond 1.5°C, which would be crossed sometime in the 2030s. The IPCC has repeatedly confirmed the drastic increases in risks for ecosystems and livelihoods, as well as risks of crossing tipping points if warming was to exceed 1.5°C.

However, we know achieving stringent near-term emission reductions by 2030 could significantly slow down warming over the next 20 years and avoid exceeding 1.5°C altogether.

Paris compatible pathways

The Paris Agreement temperature goal is one goal, and emission pathways compatible with achieving it require a very high chance of limiting warming to below 2°C, while simultaneously keeping 1.5°C within reach. The IPCC Special Report on Global Warming of 1.5°C (SR1.5) scenario provides an assessment and mitigation benchmarks for pathways that are “as likely as not” (between 33% and 66% chance) to limit warming to 1.5°C. These pathways also provide a “very likely” (>90%) or higher chance of holding warming to “well below 2°C”. In these pathways, emissions reduce strongly in the 2020s and 2030s on their way to net zero CO2 by 2050 and net zero greenhouse gases by 2070.

The IEA’s Announced Pledges Scenario does not have these characteristics, and is not compatible with the Paris Agreement’s long-term temperature goal.

Earlier this year, the IEA itself developed a Paris Agreement compatible Net Zero Scenario (see blue line in the graph above), which demonstrates that strong emissions reductions are not only necessary to achieve the Paris Agreement, but also technologically and economically achievable.

Conclusions

Only stronger mitigation action in the next decade can bring the world on track towards the Paris Agreement.

Our recent report, Closing the Gap, demonstrated that, if the G20 countries aligned their 2030 targets (National Determined Contributions, NDCs) with 1.5°C, and net zero CO2 by mid-century, end-of-century temperature rise could be limited to 1.7°C. Crucially, this scenario involves a substantial narrowing of the 2030 emissions gap and therefore would represent real progress in keeping 1.5°C within reach.

In contrast, the IEA’s Announced Pledges Scenario still leaves an enormous gap in 2030.

Decarbonisation targets and 1.5℃ pathways

Publications

What good looks like: G7 climate policy 2024 update

This brief outlines seven key policy recommendations for this June’s G7 summit that, if adopted, would demonstrate the ambition and leadership needed to keep the Paris Agreement’s 1.5°C limit in sight.

Tripling renewables by 2030: interpreting the global goal at the regional level

At COP28, governments agreed to triple global renewable capacity by 2030. This report breaks down what a 1.5ºC-aligned renewables rollout would look like at the regional level and calculate the associated investment needs.

Submission to the Australian Treasury consultation on the Petroleum Resource Rent Tax

As the gas industry in Australia has grown exponentially, the profit taxes it pays to the government have proportionally plummeted, presenting an opportunity to change this regime. Here, we respond to the Australian Government Treasury consultation on the Petroleum Resource Rent Tax (PRRT) – anti-avoidance provisions and clarifying treatment of ‘exploration’ and Mining, Quarrying or Prospecting Rights.

COP28 initiatives will only reduce emissions if followed through

Few of the sectoral initiatives announced during COP28 will meaningfully contribute to closing the emissions gap. Many of them lack either the ambition, clarity, coverage or accountability needed to really make a difference.

Unabated: the Carbon Capture and Storage 86 billion tonne carbon bomb aimed at derailing a fossil phase-out

The climate talks at COP28 have centred around the need for a fossil fuel phase-out. Our analysis quantifies the risk posed by restricting a phase-out commitment to only ‘unabated’ fossil fuels.

No change to warming as fossil fuel endgame brings focus onto false solutions

The CAT's annual warming estimate has risen by 0.1˚C to 2.5˚C. The estimate is largely influenced by weak existing targets rather than shifts triggered by updated Nationally Determined Contributions.

Submission on Australia's future gas strategy

The Australian government asked for answers to its questions around the future of its gas strategy. This was our submission.

When will global greenhouse gas emissions peak?

The IPCC says peaking before 2025 is a critical step to keep the 1.5°C limit within reach. With emissions set to rise in 2023, this leaves limited time to act. To assess if we can meet this milestone, we look at when global emissions might peak, as well as what we can do to get there in time.

Wind and solar benchmarks for a 1.5°C world

This report presents a detailed methodology for determining the amount of wind and solar capacity that is required for a country to align with the Paris Agreement’s 1.5°C temperature goal. While the focus of the report is the method, it includes illustrative benchmarks for Brazil, China, India, Indonesia, Germany, South Africa.

A 1.5°C future is possible: getting fossil fuels out of the Philippine power sector

The Philippines is also one of the fastest-growing developing countries: poverty is in decline, access to energy is rising and, with that, demand for energy services. However, fossil fuels still dominate the energy system, accounting for 78% of power generation in 2022. This report sets out what the Philippines government needs to do to get the country’s power sector onto a 1.5˚C compatible emissions pathway, replacing fossil fuels with renewable energy.

State of Climate Action 2023

This report finds that global efforts to limit warming to 1.5°C are failing across the board, with recent progress made on every indicator – except electric vehicle sales – lagging behind the pace and scale needed to address the climate crisis.

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Production Gap Report 2023

Governments, in aggregate, still plan to produce more than double the amount of fossil fuels in 2030 than would be consistent with limiting warming to 1.5°C. The persistence of the global production gap puts a well-managed and equitable energy transition at risk.

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Decarbonisation targets and 1.5℃ pathways

Comment

1.5°C remains out of reach in the IEA's Announced Pledges Scenario