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UNEP warns of imminent 1.5°C breach, urges urgent action to reverse global warming – EnviroNews
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Global temperatures are likely to exceed the critical 1.5°C warming threshold within the next few years, exposing communities and ecosystems to increasingly severe climate risks, according to a new report by the United Nations Environment Programme (UNEP).
However, the report says it is still possible to bring global temperatures back below the Paris Agreement target if governments take immediate and sustained action to sharply cut greenhouse gas emissions and scale up efforts to remove carbon dioxide from the atmosphere.
The UNEP report, Limiting Overshoot, outlines what it describes as an “overshoot, peak and decline” pathway as the best remaining option for limiting the scale and duration of a temporary breach of the 1.5°C threshold and returning temperatures below that level as quickly as possible.
UN Secretary-General, António Guterres, said recent extreme weather events offered a stark warning of the consequences of continued climate inaction.
“This summer’s scorching heat, raging wildfires and deadly floods are a warning of what lies ahead,” Guterres said. “We must make the overshoot above 1.5 degrees as small and short as possible. That demands an overshoot of ambition.”
According to the report, the pathway requires immediate and sustained reductions in greenhouse gas emissions, including methane, as countries move towards net-zero emissions. It also calls for long-term net-negative emissions, supported by carefully governed Carbon Dioxide Removal (CDR), including approaches such as afforestation and other methods of removing and storing carbon from the atmosphere.
UNEP stressed that emissions reductions must be accompanied by stronger adaptation measures to reduce the vulnerability of societies, communities and economies to existing and future climate impacts.
The report warned, however, that adaptation has limits and that some impacts could become irreversible, particularly if peak global temperatures are allowed to rise significantly.
“There are no good outcomes if we remain above 1.5°C,” said Inger Andersen, Executive Director of UNEP.
“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.
“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.”
Devastating consequences
UNEP said even the most optimistic scenario projects that global warming could peak at around 1.8°C above pre-industrial levels, exceeding the Paris Agreement goal of limiting temperature rise to 1.5°C. Most other scenarios project even higher levels of warming.
The report warned that every additional fraction of a degree above 1.5°C would intensify climate risks, particularly if elevated temperatures persist for prolonged periods.
Expected consequences include more frequent and severe extreme weather events, accelerating ecosystem loss and increased threats to Small Island Developing States and low-lying coastal cities.
Human health, food production, water supplies, biodiversity, infrastructure and economies are also expected to face growing pressure.
The likelihood of triggering irreversible climate tipping points will increase as temperatures rise and remain elevated, UNEP warned.
Among the potential tipping points identified are the destabilisation of major ice sheets, degradation of the Amazon rainforest and disruption of the Atlantic Meridional Overturning Circulation, a major system of ocean currents that plays a critical role in regulating the global climate.
Some of these changes could occur abruptly, while others may develop gradually but become increasingly difficult or impossible to reverse.
The report argued that the scale of the threat, combined with the wider benefits of climate action, should drive faster global cooperation.
A rapid transition away from fossil fuels towards renewable energy, for example, could simultaneously reduce emissions, improve air quality and public health, lower energy costs and expand access to electricity.
Political will and finance critical
UNEP identified strong political leadership, international cooperation, effective policies, inclusive governance and adequate financing as critical conditions for success.
It also stressed that equity and justice must underpin the global response, with countries that bear greater historical responsibility for climate change expected to act faster and demonstrate greater ambition.
The report said mitigation and adaptation must advance simultaneously, noting that the two are mutually reinforcing.
Interventions capable of delivering both emissions reductions and resilience benefits, including nature-based cooling solutions, should be prioritised.
While adaptation measures implemented today will provide the foundation for future resilience, UNEP said adaptation strategies must become increasingly transformational and capable of responding to emerging, non-linear and abrupt climate risks.
The report also emphasised that achieving net-zero emissions should be seen as a milestone rather than the final destination.
Returning global temperatures below 1.5°C would eventually require net-negative emissions, with carbon dioxide removal playing a supporting role alongside — and not as a substitute for — deep and sustained emissions cuts.
UNEP cautioned that CDR could only credibly contribute to lowering temperatures if peak warming remains well below 2°C and residual emissions are drastically reduced.
Strong governance frameworks will also be required to ensure that carbon removal is deployed responsibly and does not undermine environmental integrity or social equity.
Preparing for a changed world
The report warned that years of delayed climate action mean some irreversible losses and permanent changes are now unavoidable, even if global temperatures eventually fall below 1.5°C.
Communities may be forced to relocate or abandon traditional livelihoods, while governments and societies will face the difficult task of adapting to fundamentally changed environmental and economic conditions.
These challenges, UNEP said, raise complex questions around justice, power and political legitimacy and will require new and more inclusive governance arrangements.
The report described the “overshoot, peak and decline” pathway as a new frontier for global climate action, warning that it cannot be postponed for future generations to address.
Chris Bowen, Australian Minister for Climate Change and Energy and President of Negotiations for COP31, said every fraction of a degree of warming would bring increasingly severe consequences.
“Every fraction of a degree of warming above 1.5 leads to increasing and increasingly severe climate impacts, with our Pacific family standing on the frontlines,” Bowen said.
“While we know the challenge is growing, so too is momentum. The recent energy crisis has reminded the world of the need to reduce our dependence on fossil fuels, accelerate the transition to renewable energy and bolster climate cooperation.”
He said COP31 presented an opportunity for countries to translate growing ambition into practical climate action.
Similarly, COP31 President-Designate, Murat Kurum, said exceeding 1.5°C must not be treated as a new climate destination.
“Every fraction of a degree matters, and every year spent in overshoot increases climate risks and the potential for irreversible losses,” Kurum said.
“The Overshoot Report makes clear that exceeding 1.5°C should not be seen as a new destination, but as a pathway we must urgently work to minimize and reverse.”
He called for rapid and sustained emissions reductions, ambitious adaptation measures and stronger efforts to accelerate electrification, cut methane emissions, strengthen urban resilience and protect marine and coastal ecosystems.
“The choices we make today will determine how high temperatures peak, how long they remain there, and how safely we can return to 1.5°C,” Kurum added.
