A new report from the United Nations has concluded that the world will inevitably exceed the 1.5-degree Celsius warming threshold established by the Paris Climate Agreement within the next few years. The annual Emissions Gap report, released Wednesday, marks the first time the UN has officially labeled this breach as both imminent and unavoidable. The focus for global leaders, who are set to gather for the COP31 climate talks in Turkey next month, must now shift to minimizing the duration and extent of this temperature "overshoot" to eventually return global averages to safer levels.
"We are now saying this window has closed, but we can open it again by making the overshoot as brief as possible," said Inger Andersen, Executive Director of the UN Environment Program. "This is about how to find a way back as shortly and as quickly as possible with as limited an overshoot as possible."
Unlike previous assessments that focused on the feasibility of staying under the 1.5C limit, this year’s study examines scenarios for limiting peak warming to between 1.7C and 1.8C before using emissions cuts and carbon removal technologies to lower temperatures back to 1.5C by 2100. The report emphasizes that every fraction of a degree beyond the 1.5C mark increases the risk of irreversible environmental damage, including the loss of ice sheets, permafrost degradation, and harm to coral systems.
Achieving this best-case scenario requires aggressive global action that far exceeds current commitments. The report calls for greenhouse gas emissions to be reduced by 18% by 2030, 45% by 2035, and 69% by 2040, compared to 2025 levels. Additionally, it mandates a tripling of renewable energy capacity by 2035, the phaseout of coal by 2040, and the large-scale deployment of unproven carbon removal technologies.
Current policies and pledges fall significantly short of these requirements. If nations meet their existing reduction commitments, the world is on track for a peak warming of 2.1C. If countries only follow current policies, that figure could rise to 2.8C. The report notes that the estimate for current policies has worsened since last year, partly due to the United States withdrawing from the Paris Agreement and retracting its emissions reduction pledges.
Climate scientist Michael Mann of the University of Pennsylvania, who was not involved in the report, noted the severe consequences of failing to act. "Each added fraction of a degree of warming can have an immense impact as measured in terms of damage, cost and loss of lives," Mann said. He added that every additional 0.1C of warming "permanently cuts global GDP by roughly 1.2% (over $1.2 trillion annually) and pushes approximately 140 million more people into life-threatening, dangerously hot climates."
Despite the grim outlook, some experts argue that the 1.5C threshold should not be viewed as a definitive point of failure. Kate Marvel, a climate scientist at Project Drawdown, emphasized that the primary goal remains the rapid reduction of greenhouse gas emissions. "There’s nothing special about any given temperature threshold," Marvel said. "Passing 1.5 degrees is a sign that we’re not moving fast enough, but it doesn’t mean we’re doomed."
