“This summer’s scorching heat, raging wildfires and deadly floods are a warning of what lies ahead,”
By Moses Okorie
The United Nations Environment Programme (UNEP) has cautioned that global temperatures could surpass the 1.5°C threshold set under the Paris Agreement within the coming years, with potentially devastating consequences for people and the environment.
In its latest report, “Limiting Overshoot,” UNEP said the temperature goal could still be recovered if nations urgently reduce greenhouse gas emissions, strengthen climate adaptation and eventually achieve net-negative emissions.
The report proposed an “overshoot, peak and decline” approach as the most viable pathway for limiting both the level and length of time global temperatures remain above 1.5°C.
Under the proposed pathway, temperatures would temporarily rise above the threshold, reach a peak and then decline as global emissions fall to net zero and subsequently become net negative through sustained carbon dioxide removal.
UNEP said the most favorable scenario would see global warming peak at approximately 1.8°C above pre-industrial levels, while other scenarios could result in considerably higher temperatures.
It warned that even small increases above 1.5°C, as well as the length of time the world remains above the threshold, would significantly increase climate-related dangers.
Such risks include more intense extreme weather events, destruction of ecosystems and worsening threats to human health, food supplies, water resources, infrastructure and economic stability.
The report also raised concerns about climate tipping points that could become irreversible if warming continues at higher levels for extended periods. These include the destabilization of major ice sheets, deterioration of the Amazon rainforest and disruption of the Atlantic Meridional Overturning Circulation.
According to UNEP, adaptation measures will remain crucial because some effects of climate change are already unavoidable. However, it said the ability of societies to adapt would become increasingly constrained as temperatures rise.
The agency called for mitigation and adaptation measures to be implemented simultaneously, highlighting nature-based solutions such as cooling through natural ecosystems as examples of interventions that could serve both purposes.
UNEP also identified carefully managed carbon dioxide removal as an important component of efforts to eventually bring temperatures below 1.5°C. Such measures include afforestation and other technologies and practices for extracting carbon from the atmosphere.
It stressed, however, that carbon removal should complement substantial reductions in emissions and must not be used as an alternative to cutting greenhouse gas emissions.
The report identified political leadership, international collaboration, effective policies, inclusive decision-making, adequate climate financing and fairness as essential to achieving the goal.
It further said countries that have contributed most to global climate change have a greater responsibility to act quickly and adopt more ambitious measures.
UNEP warned that returning global temperatures below 1.5°C in the future would not erase all the damage caused during the period of overshoot. Some losses and changes could become permanent, forcing communities to relocate or modify their traditional livelihoods.
UN Secretary-General António Guterres urged countries to ensure that any period above the 1.5°C threshold is kept as short and limited as possible.
“This summer’s scorching heat, raging wildfires and deadly floods are a warning of what lies ahead,” Guterres said.
He stressed that minimizing temperature overshoot would require a corresponding increase in ambition and urgent climate action.
UNEP Executive Director Inger Andersen similarly warned that the consequences of rising temperatures were already becoming more severe.
“There are no good outcomes if we remain above 1.5°C,” Andersen said, urging governments to accelerate emissions reductions, strengthen resilience and improve adaptation measures.
Australian Climate Change and Energy Minister Chris Bowen, President of Negotiations for COP31, said every additional fraction of warming mattered, particularly to Pacific communities that are highly vulnerable to climate change.
He called for COP31 to focus on practical measures, including faster deployment of renewable energy, reduced dependence on fossil fuels and stronger international climate cooperation.
COP31 President-Designate Murat Kurum said crossing the 1.5°C threshold must not be accepted as a permanent climate reality.
He said the report demonstrated the need to treat any overshoot as a temporary situation that the international community must urgently work to minimize and reverse.