(BBC) Our overheating world is likely to break a key temperature limit for the first time over the next few years, scientists predict.
Researchers say there’s now a 66% chance we will pass the 1.5C global warming threshold between now and 2027.
The chances are rising due to emissions from human activities and a change in weather patterns expected this summer.
If the world passes the limit, scientists stress the breach, while worrying, will likely be temporary.
Hitting the threshold would mean the world is 1.5C warmer than it was during the second half of the 19th Century, before fossil fuel emissions from industrialisation really began to ramp up.
And breaking the limit even for just one year is a worrying sign that warming is accelerating and not slowing down.
The 1.5C figure has become a symbol of global climate change negotiations. Countries agreed to “pursue efforts” to limit global temperature rises to 1.5C under the 2015 Paris agreement.
Going over 1.5C every year for a decade or two would see far greater impacts of warming, such as longer heatwaves, more intense storms and wildfires.
But passing the level in one of the next few years would not mean that the Paris limit had been broken. Scientists say there is still time to restrict global warming by cutting emissions sharply.
Since 2020 the World Meteorological Organisation has been giving an estimate of the chances of the world breaking the 1.5C threshold in any one year.
Back then they predicted there was less than a 20% chance of breaking 1.5C in the five years ahead.
By last year this had increased to 50%, and now it’s jumped to 66%, which the scientists say means it’s “more likely than not.”
What does going over 1.5C mean?
The figure is not a direct measure of the world’s temperature but an indicator of how much or how little the Earth has warmed or cooled compared to the long term global average.
