The world could cross the 1.5°C long-term global warming threshold by September 2029 if current warming trend continues, the Copernicus Climate Change Service announced on Thursday, a timeline that is significantly sooner than the “early 2030s” projection that was widely agreed upon by scientists.
Ambient temperatures have already reached 1.38°C above the pre-industrial levels, the service known as C3S reported.
“The C3S global temperature trend monitor, based on #ERA5, allows you to explore how the estimate of the time to 1.5°C global warming has changed in recent years. While it should not be interpreted as a forecast, it does show trends in global warming,” C3S wrote on X, referring to steep warming trends since the 2000s and attaching a graph that showed the point at which the current trend would surpass the crucial threshold.
The service, known as C3S, reported that global warming already reached 1.38 degrees Celsius above pre-industrial levels in February 2025.
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The 1.5-degree threshold was at the heart of the landmark 2016 Paris climate deal – now itself in jeopardy since the US under new president Donald Trump withdrew from it. Breaching the 1.5-degree threshold represents a critical turning point for the planet, after which climate impacts become significantly more severe and widespread. At 1.5 degrees of warming, about 14% of Earth’s population would be exposed to severe heat waves at least once every five years, while at 2 degrees, this proportion would more than double to 37% of the population.
For the first time in the ERA5 dataset — a detailed global atmospheric record — surface temperatures reached or exceeded 1.5°C above the 1850-1900 average for 12 consecutive months, C3S reported.
The service provides monthly updates on global surface air temperatures using the latest reanalysis data. By analysing the 30-year linear trend leading to the most recent data, it estimates current warming levels and projects when key thresholds may be crossed.
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“With warming exceeding 1.5°C last year, if only temporarily, we are entering a zone where risks of climate change are high,” said Jim Skea, chairman of the Intergovernmental Panel on Climate Change (IPCC), who spoke at the World Sustainable Development Summit in Delhi earlier this month.
“Warm water coral reefs could disappear completely with 2 degrees Celsius warming, and land-based systems are at high risk associated with wildfires, permafrost degradation, and biodiversity loss… truly every fraction of a degree matters,” Skea added.
M Rajeevan, former secretary of India’s Ministry of Earth Sciences, called the findings alarming but not unexpected. “This is a very interesting and important plot. We are crossing the threshold of 1.5°C much before than expected. This will have serious repercussions in terms of extreme weather events. Sorry to see we are not learning from past lessons,” he said.
The synthesis report of the Sixth Assessment Report (AR6) of the IPCC — the latest estimates by the internationally accepted scientific authority on climate change — predicted in 2023 that the 1.5°C threshold will likely be breached in the early 2030s.
Most parts of the world have recorded unprecedented temperatures in the past 18 months, including India. This was partly due to an El Niño weather pattern that began in May 2023 and ended in May 2024. However, even during the subsequent weak La Niña phase — which typically brings cooler temperatures — India experienced record heat in December, January and February.
The C3S projections come amid shifting climate policies in several countries, particularly the US. President Donald Trump signed an executive order shortly after taking office directing the US to withdraw from the Paris climate agreement. The US delegation also did not participate in the IPCC meeting in China last week, indicating its withdrawal from the organisation’s seventh assessment cycle currently underway.
The Trump administration has also dismissed hundreds of researchers and meteorologists at the National Oceanic and Atmospheric Administration (NOAA), a move scientists warn will significantly impact climate forecasting and research globally.
Climate action appears to be slowing, as few countries have updated their nationally determined contributions (NDCs) — plans outlining climate actions — by the February deadline. Most G20 members, including major economies such as China, India, and the European Union, have yet to announce their 2035 NDCs and have missed the United Nations Framework Convention on Climate Change deadline of February 10. Several countries have indicated plans to submit targets ahead of the COP30 climate conference in Belém, Brazil, in November. Canada, Japan, Brazil, the United Kingdom and the United Arab Emirates are among the few that have updated their NDCs.
In a 2023 interview with Hindustan Times, Skea, then IPCC vice chair, warned: “Global warming of 1.5 degrees Celsius and 2 degrees Celsius will be exceeded during the 21st century unless there are deep reductions in CO2 and other greenhouse gas emissions in the coming decades.”