Nairobi, Kenya – September 2, 2026
A landmark report from the UN Environment Programme confirms that global temperature rise is set to cross the 1.5°C threshold, likely within the next few years. The new analysis presents a narrow pathway to limit damage and restore climate stability.
The report, titled Limiting Overshoot, identifies a three-phase strategy—"overshoot, peak and decline"—as the best remaining option to minimize the magnitude and duration of warming above 1.5°C while working toward a return to below that threshold.
Across the globe, extreme heatwaves are already proving that climate impacts will strike faster, hit harder, and last longer, costing more lives and causing deeper disruption. Above 1.5°C, risks and impacts intensify with every extra fraction of a degree and every year.
"There are no good outcomes if we remain above 1.5°C," said Inger Andersen, Executive Director of UNEP. "Now is the time we must double down on climate action. We can—and must—get on the right path."
The Narrow Pathway
The report outlines how global temperatures could be returned to 1.5°C this century, but only if heating stays below about 1.8°C. Beyond that mark, cooling the Earth back to 1.5°C this century becomes increasingly challenging.
Immediate and sustained cuts to greenhouse gas emissions, including methane, must be paired with long-term net-negative emissions through carefully governed Carbon Dioxide Removal (CDR). These measures are essential to the mix, not alternatives to sustained reductions in emissions.
The authors stress that every fraction of a degree matters, and every year spent in overshoot increases climate risks and the potential for irreversible losses.
Escalating Risks
Anticipated impacts of sustained warming above 1.5°C include intensified extreme weather, ecosystem loss, and submersion of Small Island Developing States and low-lying coastal cities. Glaciers could lose more than a quarter of their remaining mass by 2100, raising sea levels by up to 13cm.
Global food production could decline by up to 14% by 2050 without effective adaptation strategies. Severe damage to human health, water supplies, nature, cities, infrastructure, and economies is expected. The report warns that irreversible losses and permanently changed conditions are certain even if a return to below 1.5°C is secured.
Many communities may be forced to relocate or change livelihoods, raising issues of justice, power, and political legitimacy that will require new, inclusive governance arrangements to resolve.
Immediate Action Required
The report identifies mitigation and adaptation as mutually reinforcing actions that must advance together. Interventions that achieve both goals—such as nature-based cooling—should be prioritized.
Strong political will, multilateralism, effective policies, inclusive governance, and finance are all important enabling conditions for action. Countries with greater responsibility for climate change should act the fastest with the greatest ambition.
Equity and justice must underpin all responses. Strong governance frameworks for CDR are critical to allow responsible deployment and manage implications for environmental integrity, equity, and scale.
"Every fraction of a degree matters, and every year spent in overshoot increases climate risks and the potential for irreversible losses," said H.E. Murat Kurum, COP31 President-Designate. "We need to accelerate global electrification, reduce methane emissions from waste, and align mitigation and adaptation choices we make today will determine how high we peak, how long we remain there, and how safely we can return to 1.5°C."
A Generational Challenge
The report emphasizes that net-zero is a milestone toward net-negative, not the finish line. Years of inaction mean that even if a return to below 1.5°C is secured, irreversible losses and permanently changed conditions are certain.
The overshoot, peak and decline pathway is a next-generation climate frontier that cannot be left unattended to for the next generation to tackle. Immediate action is required for such a pathway to remain possible.
Source: UN Environment Programme (UNEP), Limiting Overshoot report, September 2, 2026. The Guardian, September 2, 2026. Health Policy Watch, September 2, 2026. EOS, September 2, 2026.
FIRAT Editorial Board
Institutional Research Desk · Foresight Institute of Research and Translation
The collective editorial and research translation board of FIRAT, synthesising peer-reviewed evidence, policy briefs, and division milestones across our seven foundational research pillars.
