UN Report Warns Global Warming Will Surpass 1.5°C Limit, Outlines Path Back To Safer Levels

UN Warns World Will Overshoot 1.5°C Warming Limit, Urges Global Action To Cool Planet

The United Nations has acknowledged that the world is likely to exceed the 1.5°C global warming threshold set under the Paris climate agreement, shifting the focus from preventing the breach to limiting how far temperatures rise and eventually bringing them back down.

A new report from the UN Environment Programme (UNEP) warns that continued emissions from coal, oil and gas will push global temperatures beyond the internationally agreed threshold within the next few years.

Rather than abandoning the 1.5°C goal, scientists and UN officials say governments must prepare for a period of “overshoot” — in which temperatures rise above the limit before gradually declining.

“Humanity is speeding past the limit to avoid climate catastrophe,” UN Secretary-General António Guterres said.

World Could Face Decades Above 1.5°C

The 1.5°C target is measured against average temperatures in the pre-industrial period. The planet is already around 1.4°C warmer than those levels, based on a longer-term average rather than the temperature recorded in any single year.

The latest UN assessment says the world will cross the 1.5°C threshold “in the next few years”.

Under the most ambitious scenario, global warming could peak at around 1.8°C in the middle of the century before declining. However, current government policies could result in warming of approximately 2.6°C by 2100.

The report therefore outlines a “hump-shaped” trajectory: temperatures first rise beyond 1.5°C, remain above the threshold for an extended period, reach a peak and eventually decline.

UNEP Executive Director Inger Andersen said 1.5°C remains the goal, but the world must now consider how to return to that level after crossing it.

Every Fraction Of A Degree Matters

Scientists stressed that crossing 1.5°C does not represent an irreversible point at which climate action becomes meaningless.

The priority, according to the report, is to keep the eventual temperature peak as low as possible and reduce the amount of time the planet spends above the threshold.

Climate scientist Richard Betts of the University of Exeter, one of the report’s authors, said the world would have to adapt to a warmer climate but still had opportunities to reduce the severity of future warming.

Another report co-author, Imperial College London scientist Joeri Rogelj, said every five-year delay in cutting emissions could add at least another 0.1°C to peak warming.

The report argues that acting immediately could substantially limit the extent of the overshoot, even if returning below 1.5°C takes decades.

Extreme Weather And Climate Risks To Intensify

The period of excessive warming is expected to bring increasingly severe consequences, particularly for vulnerable populations.

The UN report warns of higher risks of deaths and illness linked to extreme weather, declining food production, worsening water shortages, economic damage and the loss of vulnerable ecosystems such as coral reefs.

Scientists also highlighted the threat of climate “tipping points”, which could trigger irreversible or cascading changes. These include major ice-sheet loss in Greenland and West Antarctica, damage to the Amazon rainforest and disruption of Atlantic Ocean circulation.

Some areas could eventually become increasingly difficult to insure or even unsuitable for human habitation, the report warned.

The effects are expected to be especially severe for poorer communities, prompting the UN to call for greater investment in adaptation measures alongside emissions cuts.

Carbon Removal Seen As Key To Cooling

The final stage of the UN’s proposed strategy involves removing carbon dioxide from the atmosphere and storing it.

Planting and restoring forests can contribute to carbon removal, but the report estimates that this approach alone could reduce global temperatures by only around a tenth of a degree.

That means governments may need to expand the use of newer carbon-removal technologies. However, scientists have raised concerns over their cost, reliability and ability to operate at the enormous scale required.

Stanford climate scientist Rob Jackson, who was not involved in the report, described the challenge as stopping global emissions quickly enough and then effectively reversing the buildup of greenhouse gases.

The UN’s message is therefore not that the climate fight is over, but that the strategy must change: limit the peak, protect vulnerable communities during the overshoot period and ultimately bring global temperatures back below the 1.5°C threshold.