Temperatures forecast to cross 1.5°C threshold in next five years

New highs set to be fuelled by heat-trapping greenhouse gases and El Nino

A wildfire in Jurupa Valley, California. Last year's average global temperature was about 1.15°C higher than the 1850-1900 average. Getty

A global average temperature more than 1.5°C above pre-industrial levels is likely to be recorded over the next five years, exceeding the target set out in the Paris climate accords, the World Meteorological Organisation has said.

It suggested there is a 66 per cent chance of this being recorded at least once between now and 2027, as scientists predict the globe will experience one of the warmest years on record in the next five years.

Britain's Met Office, on behalf of the WMO, has predicted a 98 per cent chance of this occurring.

The WMO forecast is among a number of findings in its Global Annual to Decadal Climate Update report, which was published on Wednesday.

It predicts a two-in-three chance that global average temperatures in at least one of the next five years will temporarily exceed the 1.5°C limit ratified in the 2015 Paris Agreement.

The report comes shortly after the world's fourth warmest April since records began in 1950 and months ahead of the Cop28 summit in the UAE.

The hottest eight years ever recorded were all between 2015 and 2022, but temperatures are forecast to increase further as climate change accelerates.

Leon Hermanson, one of the Met Office scientists behind the report, said: “We have never crossed 1.5°C. The current record is 1.28°C.

“It’s very likely we’re going to exceed that, we might even reach 1.5°C – it’s more likely than not that we will.

“It’s not this long-term warming that the Paris Agreement talks about, but it is an indication that as we start having these years, with 1.5°C happening more and more often, we’re getting closer and closer to having the actual long-term climate being on that threshold.”

He said greenhouse gases would fuel the rising temperature.

“Today’s report shows that the next five years are expected to bring new temperature records,” he said.

“These new highs will be fuelled almost completely by the rise of heat-trapping greenhouse gases in the atmosphere, but the anticipated development of the naturally occurring El Nino event will also release heat from the tropical Pacific.”

El Nino events are declared when sea temperatures in the eastern Pacific rise 0.5°C above the long-term average.

The Met Office predicts El Nino and human-induced climate change are likely to combine, leading to global temperature increases next year.

“This report does not mean that we will permanently exceed the 1.5°C level specified in the Paris Agreement — which refers to long-term warming over many years,” WMO secretary general Petteri Taalas said.

“However, WMO is sounding the alarm that we will breach the 1.5°C level on a temporary basis with increasing frequency.”

The 2015 Paris Agreement saw countries agree to cap global warming at "well below" two degrees Celsius above average levels measured between 1850 and 1900 - and 1.5°C if possible.

Last year, the average global temperature was about 1.15°C above the 1850-1900 average.

The Met Office has said with the cooler conditions of La Nina ending in March, El Nino is forecast to develop in the coming months.

Typically, El Nino increases global temperatures in the year after it develops — 2024 in this case, the Met Office said.

“Global temperatures are predicted to continue increasing, moving us away further and further away from the climate we are used to,” Dr Hermanson said.

The annual mean global near-surface temperature for each year between 2023 and 2027 is predicted to be between 1.1°C and 1.8°C higher than the 1850-1900 average, the baseline to represent pre-industrial temperatures.

There are also fears Arctic heating will be more than three times higher than the global average.

The Met Office has warned that Arctic warming is “disproportionately high” compared to the 1991-2020 average.

It predicts the temperature anomaly will be more than three times as high as the global mean anomaly when averaged over the next five extended winters in the Northern Hemisphere.

Mr Taalas warned on Wednesday that gas pipelines will be under threat due to rising sea levels in the Arctic.

“Over the coming years the Arctic will be three times warmer than average and we will see a dramatic impact there,” he said.

“The Arctic will see record changes and it will have a big impact on the eco system and will have a big impact on the fisheries and the gas pipelines will be endangered due to the high levels of water."

Increased rainfall is also predicted for May to September over the next five years in the Sahel, northern Europe, Alaska and northern Siberia, with reduced rainfall for this season in the Amazon and parts of Australia.

“So far the warmest year was 2016. Due to the El Nino phase the Pacific temperatures will be warmer than average. The Amazon rainforest is already vulnerable when it comes to the carbon. We will see droughts in the Amazon and this will boost the release of carbon," Mr Taalas said.

“This report shows there is a risk for the coming five years and it is bad news for agriculture, water resources and bad news for human wellbeing and there will be an enhanced risk of forest fires and we have seen growing forest fires in the Amazon.

“This demonstrates climate change is preceding. We are moving in the wrong direction when it comes to increases in temperatures.”

He said the extreme conditions could see a growing risk of unrest.

"These changes are already causing instabilities, for example there are clear indications [it] had an impact in North Africa and the Middle Eastern countries like Syria, Egypt, Libya and Tunisia," Mr Taalas said.

"They had severe droughts, it led to a rise in food prices and unemployment of people dealing with agriculture and such events are going to grow and this will have an impact on refugees here in Europe and many other parts of the world.

"This regular trend will continue for the coming decades. The risks for refugees and unrest is also growing."

The new report was released ahead of the World Meteorological Congress next week, at which delegates will discuss how to strengthen weather services to support climate-change adaptation.

It will be focusing on the Early Warnings for All initiative to protect people from increasingly extreme weather and a new Greenhouse Gas Monitoring Infrastructure to promote climate mitigation.