Earth was nearly 1.5 degrees Celsius hotter a year ago compared to pre-1700 era: Study

New Delhi: Human-induced climate change may have raised the average global temperature by nearly 1.5 degrees Celsius by the end of 2023, compared to before the 1700s, according to a new study published on Monday.

The study coincides with the start of the UN Climate Summit at Baku where countries will seek to come out with a new climate finance mechanism to tackle the dangerous consequences of climate change.

It also comes out on the same day when the World Meteorological Organisation issued a red alert, saying 2024 is on track to become the warmest year on record and the last ten years (2015-24) would end up as the warmest decade in history.

In their study in Nature Geosciences, Andrew Jarvis and Piers Forster from Lancaster University, UK have calculated that human-induced warming nearly touched 1.49 degrees Celsius in 2023 (when compared against pre 1700 CE). Going by the same yardstick, Oct 2024 was 1.53 degrees Celsius warmer than 1700s.

But checked against the time frame of 1850-1900 that is used in climate negotiations, the warming is a bit less, though it is still on course to touch the 1.5 degrees C guardrail in a decade.

“Our estimate of the Paris relevant human caused warming was 1.31 degrees Celsius in 2023 and is 1.35 C currently. This means we will pass Paris 1.5 in under 10 years,” Forster said.

The findings are based on a new approach for assessing the impact of human-induced warming using Antarctic ice core data covering the last two millennia, and suggest that Earth may be closer to the 1.5 degrees Celsius warming limit than previously thought.

“The negotiations need to stop us hurtling past 1.5 degrees to ever hotter climates and their devastating impacts. If we really co-operate and deliver on our promises, we can delay the time of crossing and limit how much we exceed 1.5C.”

In the 2015 Paris agreement, the nations agreed to pursue efforts to keep global temperatures from rising beyond 1.5 C above pre-industrial levels, with the Intergovernmental Panel on Climate Change using the 1850–1900 global temperature anomaly data as the pre-industrial baseline condition.“

If we build climate resilience into our societies, we can give the world a chance. The physics of climate change is not waiting around for geopolitics to sort itself out, so nations need to work together,” Forster said.

The 2024 climate update from WMO said the Jan-Sept 2024 global average temperature was 1.54 degrees Celsius above pre-industrial level, even though long-term warming measured over decades remains below 1.5 degrees Celsius.

According to the UN meteorological body, the past 10 years were the warmest on record with a rapid rise in ocean heat. The Antarctic sea ice level is the second lowest on record while glacier loss has accelerated.

“The level of greenhouse gases reached a record high in 2023 with real time data indicating that they would continue to rise in 2024,” the WMO report said.