Global warming breaches 1.5 degrees Celsius threshold in summer for the first time: report

“This threshold was first exceeded in December 2015, and then repeatedly in the northern hemisphere winters and springs of 2016 and 2020,” the ECMWF said in a statement.

The goal of the 2015 Paris Agreement is to ensure that the rise in global mean temperatures, as compared to pre-industrial times, does not exceed 2 degrees Celsius, and preferably be restricted within 1.5 degrees. But the thresholds mentioned in the Paris Agreement are not about daily or even annual global temperatures. Rather, those thresholds refer to long-term warming, meaning global temperatures over a period of 20 to 30 years, on an average, must not exceed 1.5 degrees or 2 degrees Celsius.

Short-term breaches of these thresholds, even a few years at a stretch, are considered inevitable now. In most of the pathways to achieve the Paris Agreement goal, including those predicted by the Intergovernmental Panel on Climate Change, the world is projected to ‘overshoot’ the 1.5 degrees threshold before coming back.

In fact, the World Meteorological Organization (WMO) had said last month that there was a 66 per cent chance that in one of the next five years (2023-27), annual global temperatures would breach the 1.5 degrees threshold. Last year, it was 1.15 degrees Celsius higher than the pre-industrial times, the WMO said. The warmest ever year, so far, has been 2016 when global mean temperatures were 1.28 degrees Celsius higher. In its last month’s statement, the WMO said it was near certain — 98 per cent probable — that one of the next five years (2023-27) would leave the year 2016 behind.

The ECMWF said the daily global temperatures could go beyond 1.5 degrees Celsius again during the rest of the year.

“As the current El Nino continues to develop, there is a good reason to expect periods in the coming 12 months during which the global mean temperature would again exceed pre-industrial levels by more than 1.5 degrees Celsius,” it said.

Incidentally, 2016 was part of one of the strongest and longest-ever El Nino phase. The El Nino currently taking shape in the Pacific Ocean is also expected to develop into a strong phase. El Ninos have an overall warming effect on the planet, accentuating the effects of global warming.

“…as the global mean temperature continues to rise and more frequently exceed the 1.5 degrees Celsius limit, the cumulative effects of the exceedance will become increasingly serious and must be carefully monitored to keep track of how rapidly we are closing in on the long-term thresholds,” it said.