A global temperature rise of 1.5C is “more likely than not” in the next five years and we are “closer” to having the long-term climate “on that threshold”, a climate expert has warned.
Dr Leon Hermanson of the Met Office Hadley Centre said the “current record is 1.28C” and it is “very likely we are going to exceed that”.
The World Meteorological Organisation (WMO), in its latest annual State of Climate report, said there is a 66% chance of a global average temperature of 1.5C being recorded at least once between now and 2027 – which would mark the first time in human history.
It added that there is also a 98% chance of the hottest year on record being broken during that time.
If a 1.5C temperature rise is recorded, it would not mean the target set during the Paris Agreement in 2015 would be lost as the global average temperature would need to exceed 1.5C many more times before the climate can be said to have permanently warmed to that level.
In the Agreement the world’s nations committed to reducing greenhouse gas emissions to keep global temperatures below 2C and to try for 1.5C before the end of the century.
The WMO said there is only a 32% chance that temperatures will exceed the 1.5C threshold in the next five years.
Dr Hermanson added: “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 1.5C happening more and more often, we’re getting closer and closer to having the actual long-term climate being on that threshold.”
The latest WMO report also predicts temperatures in the Arctic will increase three times faster than the global average while greenhouse gases will also lead to more ocean acidification, sea ice and glacier melt, sea level rise and more extreme weather.
The WMO general secretary Professor Tallas said: “This report does not mean that we will permanently exceed the 1.5C level specified in the Paris Agreement which refers to long-term warming over many years.
“However, WMO is sounding the alarm that we will breach the 1.5C level on a temporary basis with increasing frequency.”
Dr Hermanson said the record temperatures will likely come from a combination of greenhouse gases and a naturally-occurring El Nino event. The WMO said that the opposite weather event, La Nina, has now ended after taking hold over the last three years.
El Nino is a heating of the eastern Pacific which affects rainfall and temperature globally while La Nina refers to a period of cooling. Typically, El Nino increases global temperatures the year after it develops so scientists are expecting temperatures to rise in 2024.
Professor Tallas warned the world “should prepare” for El Nino as it can trigger more extreme weather and climate events including severe rainfall and drought.
He added that the weather event will “push global temperatures into uncharted territory” which would have “far-reaching repercussions for health, food security, water management and the environment.”
The Intergovernmental Panel on Climate Change has said damage wrought to people and wildlife will increase with every increment of global warming, adding that the world is currently on course to warm to well beyond 2C by the end of the century with the emissions reduction policies currently in place.