There is a 40% chance of the world temporarily hitting the 1.5C temperature rise threshold in one of the next five years, scientists have warned.
A new climate update warns the odds of the world experiencing global annual temperatures that are 1.5C above pre-industrial levels in one of the next five years are increasing with time.
The report published by the World Meteorological Organisation (WMO) also warns of a very high likelihood – a 90% chance – of at least one year between 2021 and 2025 becoming the warmest on record, outstripping 2016’s record heat.
Global average temperatures of 1.5C above 19th century levels are seen as a threshold beyond which the most dangerous impacts of climate change will be felt.
In 2020, the global average temperature was 1.2C above pre-industrial levels, making it among the three hottest years on record.
The global annual to decadal climate update, produced by the UK Met Office, the WMO’s lead on such predictions, also shows that high-latitude regions and Africa’s Sahel are likely to be wetter, and there is an increased chance of more tropical cyclones in the Atlantic.
WMO secretary-general Professor Petteri Taalas said the predictions were more than just statistics.
“Increasing temperatures mean more melting ice, higher sea levels, more heatwaves and other extreme weather, and greater impacts on food security, health, the environment and sustainable development,” he said.
“This study shows – with a high level of scientific skill – that we are getting measurably and inexorably closer to the lower target of the Paris Agreement on Climate Change.
“It is yet another wake-up call that the world needs to fast-track commitments to slash greenhouse gas emissions and achieve carbon neutrality,” he said.
Under the international Paris Agreement countries pledged to limit long-term temperature rises to 2C above pre-industrial levels and pursue efforts to curb them to 1.5C, to reduce the risks and impacts of climate change.
Scientists warn that temperature rises above 1.5C will lead to more heatwaves, extreme rainstorms, water shortages and drought, greater economic losses and lower crop yields, higher sea levels and destruction of coral reefs.
Keeping to the 1.5C limit means dramatic efforts to cut carbon emissions by nearly half by 2030 and to net zero – or carbon neutrality – by 2050.
But current action promised by countries puts the world on track for 2-3C of warming by the end of the century.
Prof Taalas also warned the report underlined the need for action to adapt to the impacts of a warming world, such as in the increase in extreme weather events.
In the coming five years, the annual mean global temperature is predicted to be at least 1C warmer – with a range of 0.9C-1.8C – than pre-industrial levels.
The odds of any one year in the next five reaching the 1.5C threshold have roughly doubled compared to a similar analysis last year – mainly due to an improved temperature dataset used for the baseline, the Met Office said.
Professor Adam Scaife from the Met Office said: “Assessing the increase in global temperature in the context of climate change refers to the long-term global average temperature, not to the averages for individual years or months.
“Nevertheless, a temporary exceedance of the 1.5C level may already be seen in the next few years.”
Dr Stephen Cornelius, chief climate adviser at WWF, said: “Limiting global warming to 1.5C is of critical importance to prevent the worst impacts of the climate crisis on people and nature, but we know without global action we are at risk of reaching this threshold in the coming years.
“With so much at stake, governments must take urgent action to cut harmful emissions and restore nature, as these are essential steps to keep global temperature rises in check.”
As hosts of the G7 summit in June and the key Cop26 climate summit in Glasgow in November, the UK Government must demonstrate it will deliver on its ambitious climate targets, he said.