Major UN climate report examines pathways to limit global warming overshoot

A major new United Nations Environment Programme (UNEP) report, examining pathways to limit global warming overshoot includes contributions from PML Visiting Fellow Dr Elvira Poloczanska and references research led by PML scientist Professor Helen Findlay.

The ‘Limiting Overshoot’ report shares that global temperatures are set to cross 1.5°C above pre-industrial levels within the coming years. It identifies an ‘overshoot, peak, and decline’ pathway as the best remaining option to minimize the magnitude and duration of this overshoot and try to return to below 1.5°C as soon as possible. Every year and every fraction of a degree above 1.5°C results in increasingly severe risks for ecosystems, people, and economies worldwide.

Visiting Fellow with PML’s Office for International Affairs and former Intergovernmental Panel on Climate Change (IPCC) Science Advisor (Sixth Assessment cycle) and Assessment Author, Dr Elvira Poloczanska, is a Contributing Author on ‘Chapter 4: Adapting to overshoot realities in the context of development’ of the UNEP report.

This chapter explains that adaptation is no longer optional in a world that is likely to exceed 1.5°C warming. Adaptation and mitigation are fundamentally intertwined and must advance together. Globally, adaptation responses must become transformational, flexible and link closely with sustainable development and mitigation efforts. Current adaptation approaches are often too limited and risk becoming ineffective as climate impacts intensify so governments and communities need forward-looking, systems-based planning that addresses equity, governance and long-term resilience.

The chapter concludes that strong political will, inclusive governance and sustained investment in adaptation are essential to reduce risks, avoid maladaptation and help societies cope with irreversible climate changes across the exceedance, peak, decline and stabilisation stages of overshoot.

Dr Poloczanska comments:

“Rapid, collective and global action is critical, as there are no good outcomes in remaining above 1.5°C warming. It is sobering that the focus has shifted from avoiding overshoot to limiting its impacts and reducing the risks faced by people, communities and ecosystems around the world.”

The report also references influential research led by PML scientist Professor Helen Findlay. Her highly-regarded 2025 paper ‘Ocean acidification: Another planetary boundary crossed’ is cited within the report.

These inclusions demonstrate the continued contribution of PML fellows and scientists to international efforts addressing climate change and its impacts on the world’s ocean. It also builds on PML’s long-standing involvement with key IPCC assessments and special reports, which have informed global climate policy and action.

Read the report here: Limiting Overshoot – Navigating exceedance of 1.5°C and pathways towards return | UNEP – UN Environment Programme