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

1.5°C-aligned 2030 and 2035 GHG emissions targets

We have produced factsheets for Australia, China, the EU, India, Indonesia and USA showing 2030 and 2035 greenhouse gas emission reduction milestones for each jurisdiction to align with the Paris Agreement’s 1.5°C goal – both including and excluding land use, land-use change and forestry.

Climate Action Tracker: 2024 warming projection update

Despite an escalating climate crisis marked by unprecedented wildfires, storms, floods, and droughts, the Climate Action Tracker annual global temperature update shows global warming projections for 2100 are flatlining, with no improvement since 2021. The aggregate effect of current policies set the world on a path toward 2.7°C of warming.

Decarbonising light-duty vehicle road transport

The Climate Action Tracker provides updated 1.5ºC compatible benchmarks for the transport sector for the world as a whole and for seven individual countries; the US, EU, China, India, Brazil, South Africa and Indonesia.

Emissions Gap Report 2024: No more hot air … please!

The 2024 edition of UNEP’s Emissions Gap Report shows how much higher nations must aim. To get on a least-cost pathway for 1.5°C, emissions must fall 42 per cent by 2030, compared to 2019 levels. G20 nations, particularly the largest-emitting members, would need to do the heavy lifting.

The role of northern forests in limiting warming to 1.5°C

Northern forests are critical in the race to net zero CO₂ by mid-century. Protecting and restoring these forests, alongside steep and rapid reductions in fossil fuel emissions, is essential both to mitigating emissions and to supporting forest ecosystem services and biodiversity.

Methodology underpinning the State of Climate Action series: 2024 update

This technical note describes the State of Climate Action series’ methodology for identifying sectors that must transform, translating these transformations into global mitigation targets primarily for 2030, 2035 and 2050 and selecting indicators with datasets to monitor annual change. It also outlines the report’s approach for assessing progress made toward near-term targets and comparing trends over time.

LNG shipbuilding industry heading to huge oversupply

The LNG shipbuilding industry appears to be doubling down on building new carriers, ignoring the global shift to a low carbon economy and putting itself into an even worse oversupply situation than a year ago, we find in our updated report.

Setting 1.5°C compatible wind and solar targets

Based on global energy system modelling sense-checked against key national studies, this report presents new analysis on what a 1.5°C-aligned rollout of wind and solar could look like for key countries. It aims to inform target setting for 2030, 2035 and beyond in third generation NDCs.

Technical guide for the development of long-term low emission development strategies in Africa

This technical guide proposes concrete steps and actions to help African countries develop strong, high-performing Long-Term Low Emission and Climate Resilient Development Strategies that chart a low-emission development path, build resilience, encourage innovation, and create new opportunities for green growth.

Evaluating the near and long-term role of carbon dioxide removal in meeting global climate objectives

For 1.5°C pathways with limited overshoot, most of the mitigation between now and 2030 should come from emissions reductions (70%), with reductions from cutting non-CO2 emissions (20%) and land-based carbon dioxide removals such as afforestation and preventing deforestation (10%) making up the remainder.

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.

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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