Current fossil fuel infrastructure does not yet commit us to 1.5 °C warming

Area of Science:

• Climate Science
• Environmental Science

Background:

• Committed warming, driven by historical emissions and climate system inertia, projects future temperature increases.
• Current definitions often assume abrupt emission halts, which are socioeconomically unrealistic.
• Focusing on committed warming from present-day fossil fuel assets is crucial for actionable climate policy.

Purpose of the Study:

• To assess the likelihood of remaining below the 1.5°C warming threshold based on the retirement of existing fossil fuel infrastructure.
• To evaluate the impact of delayed mitigation actions on achieving the 1.5°C target.

Main Methods:

• Modeling committed warming from present-day fossil fuel assets.
• Analyzing the impact of phasing out carbon-intensive infrastructure at the end of its design lifetime (from end of 2018).
• Simulating scenarios with delayed mitigation (until 2030) and accelerated fossil fuel retirement.

Main Results:

• Phasing out carbon-intensive infrastructure by the end of 2018 presents a 64% probability of peak global mean temperature rise staying below 1.5°C.
• Delaying mitigation efforts until 2030 significantly diminishes the probability of achieving the 1.5°C target, even with accelerated fossil fuel asset retirement.

Conclusions:

• The 1.5°C target, while challenging under the Paris Agreement, remains attainable.
• Ambitious and immediate emission reductions across all sectors are essential to meet the 1.5°C goal.
• Strategic retirement of existing fossil fuel infrastructure is a key factor in limiting committed warming.