• Global warming is likely to exceed 1.5°C within the next few years, with UNEP’s most optimistic scenario putting peak warming at 1.8°C.
• UNEP says rapid emissions cuts, adaptation and eventually net-negative emissions offer the best remaining route back below the Paris Agreement threshold.
• Governments will need stronger climate finance, inclusive governance and credible carbon removal rules as higher temperatures increase economic and physical risks.

The world is likely to breach the Paris Agreement’s 1.5°C warming threshold within the next few years, according to the UN Environment Programme, raising the likelihood of severe climate impacts and irreversible tipping points.

UNEP’s new Limiting Overshoot report says the best remaining option is an “overshoot, peak and decline” pathway. Under that approach, temperatures temporarily rise above 1.5°C before peaking and eventually declining.

The most optimistic scenario assessed by UNEP puts peak warming at 1.8°C above pre-industrial levels. Most other scenarios point to temperatures exceeding 2°C.

“This summer’s scorching heat, raging wildfires and deadly floods are a warning of what lies ahead. We must make the overshoot above 1.5 degrees as small and short as possible. That demands an overshoot of ambition” said UN Secretary-General Antőnio Guterres.

Every fraction of warming raises the stakes

The consequences grow more severe with every additional fraction of a degree and every year spent above 1.5°C.

UNEP expects greater exposure to extreme weather, ecosystem losses and rising threats to low-lying cities and Small Island Developing States. Human health, food security, water supplies, infrastructure and economic activity are also increasingly at risk.

Higher temperatures also increase the chance of triggering irreversible changes. These include destabilisation of major ice sheets, degradation of the Amazon rainforest and disruption of the Atlantic Meridional Overturning Circulation.

Some impacts could appear suddenly. Others may accumulate over decades, increasing pressure on governments, insurers, infrastructure owners and financial institutions.

“There are no good outcomes if we remain above 1.5°C. 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,” 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. By cutting greenhouse gas emissions, strengthening resilience and adaptation, and ensuring exceedance of 1.5°C is as small and short as possible.”

Emissions cuts remain the first priority

UNEP says immediate and sustained reductions in greenhouse gases, including methane, are critical to limiting peak temperatures.

Rapid movement away from fossil fuels towards renewable energy could also deliver economic and social benefits. These include lower energy costs, improved air quality, better public health and expanded electricity access.

Mitigation, however, cannot proceed separately from adaptation. UNEP calls for both to advance together, with measures such as nature-based cooling capable of supporting emissions reduction and climate resilience simultaneously.

For businesses and investors, this broadens the climate agenda beyond decarbonisation targets. Physical climate risk, adaptation spending and resilience planning will increasingly influence capital allocation, asset values and supply-chain decisions.

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Carbon removal requires tighter governance

Returning temperatures below 1.5°C would eventually require net-negative global emissions. That makes carbon dioxide removal an essential component of UNEP’s pathway.

The report is clear that carbon removal cannot substitute for deep emissions cuts. It would need to operate alongside sustained reductions in residual greenhouse gases.

Credible deployment will also depend on strong governance. Governments and companies will need frameworks that address environmental integrity, equity and the potential scale of carbon removal projects.

A return below 1.5°C becomes far harder if peak warming approaches or exceeds 2°C, according to UNEP. That increases the urgency of near-term mitigation rather than relying heavily on future removal technologies.

Climate governance enters a harder phase

UNEP says political will, multilateral cooperation, effective policy and climate finance will determine whether an overshoot pathway remains achievable.

Equity will be central. Countries with greater historical responsibility for climate change are expected to move fastest and pursue the highest levels of ambition.

Even if temperatures eventually fall below 1.5°C, some losses will be permanent. Communities may need to relocate, livelihoods could change and societies will have to adapt to altered environmental conditions.

That creates difficult questions around justice, compensation and political legitimacy. It will also require new governance structures capable of managing climate impacts that cannot simply be reversed.

For governments, companies and investors, the implication is increasingly clear: the climate challenge is shifting from preventing every degree of warming to limiting the scale and duration of overshoot while preparing economies for lasting change. The next few years will determine how costly and disruptive that transition becomes.