The world is increasingly likely to experience global warming of 1.5C within the next five years because of record greenhouse gas levels, according to new research that adds to alarming evidence of how quickly the planet is heating.
There is a 48 per cent chance earth’s annual temperature will exceed 1.5C of warming, compared with pre-industrial levels, in one of the years between now and 2026, the World Meteorological Organization and the UK Met Office said in a report published on Tuesday. That probability is likely to keep rising, it added.
The chance of a 1.5C exceedance for the subsequent five-year period was close to zero just seven years ago, according to the data. “If we’re going to keep to 1.5C, that may be difficult now,” said Leon Hermanson, a Met Office researcher who led the report.
“The 1.5C figure is not some random statistic,” said Petteri Taalas, WMO secretary-general. “It’s an indicator of the point at which climate impacts will become increasingly harmful for people and indeed the entire planet.”
Global emissions have been rising as economic activity has rebounded after the pandemic, with carbon dioxide emissions last year reaching the highest levels ever recorded.
That makes it even more difficult to achieve the targets set by the 2015 Paris climate accord approved by 197 countries, which aims to limit global warming to “well below 2C” with best efforts to keep it below 1.5C.
Scientists have generally been reticent about predicting when exactly the 1.5C threshold will be crossed, with an Intergovernmental Panel on Climate Change report last year saying long-term average temperatures were likely to reach 1.5C higher within 20 years.
The Paris climate accord target refers to a long-term average, so it could still be intact even if annual warming topped 1.5C in any single year. The planet has already warmed about 1.1C compared with pre-industrial times.
The war in Ukraine has further set back climate co-operation, and some countries are planning to burn more coal to replace Russian gas supplies.
At the Glasgow COP26 climate summit last year, more than 80 per cent of the world’s countries had agreed to adopted net zero targets. But there has been scant policy action to implement those target in the months since, and little progress toward improved national targets ahead of the next big summit in the Egyptian resort of Sharm el-Sheikh later this year.
The Met Office and WMO scientists analysed about 120 different climate forecasts to calculate the chance of temporarily passing 1.5C. The report concluded that the hottest year on record was very likely to fall within the next five years. “Global temperatures are likely to increase in the five-year period 2022-2026,” it said.
Severe heatwaves, fires, droughts and floods are among the impacts that are becoming more likely as the world gets warmer. A prolonged heatwave across north-west India and Pakistan this month led to coal shortages and power blackouts.
“For as long as we continue to emit greenhouse gases, temperatures will continue to rise,” Taalas said.