LONDON – Carbon dioxide emissions are on track for one of the biggest increases on record in 2024, pushing the planet closer to catastrophic climate change.

That jump is the result of human-induced pollution, including the burning of fossil fuels and deforestation, compounded with the El Nino weather pattern, which weakens the ability of the world’s natural carbon sinks to absorb CO2, according to a forecast by Britain’s Met Office. The projected increase is beyond the trajectory needed to meet the Paris Climate Agreement’s goal of limiting global warming to 1.5 deg C above pre-industrial levels.

That is the cap scientists – including the United Nations-backed Intergovernmental Panel on Climate Change – say should be met to avoid the deadliest impacts of climate change, such as the irreversible melting of ice sheets leading to dangerous sea level rises. 

The Met Office forecasts the annual average CO2 concentration at Mauna Loa on Hawaii – where records date back to 1958 – will be 2.84 parts per million higher in 2024 than in 2023. That central scenario would be the fourth-largest increase in the so-called Keeling Curve – measuring the accumulation of greenhouse gases in the earth’s atmosphere – in 65 years.

However, given the range of uncertainty, it could also be the biggest-ever jump, the Met Office said. Even stripping out the impact of El Nino would still result in an increase that poses a risk to climate goals, it added.

“Even when we compensate for the temporary effects of El Nino, we find that human-induced emissions would still cause the CO2 rise in 2024 to be on the absolute limits of compliance with the 1.5 deg C pathways,” said Dr Richard Betts, author of the Met Office’s forecast.

While nearly 200 governments signed the Paris Agreement in 2015, the world looks increasingly likely to overshoot the 1.5 deg C warming limit. In 2023, the average global temperature was already about 1.5 deg C higher than the pre-industrial era, while early estimates suggest temperatures in 2024 will be 1.3 deg C to 1.6 deg C above. 

The forecasts come as IPCC scientists meet in Istanbul to set a roadmap for the next cycle of reports. They have said that to achieve the 1.5 deg C target, the rise in atmospheric CO2 would need to slow rapidly and cease completely within the next two decades. 

But 2024’s projected increase in CO2 concentration is well above all three 1.5 deg C-compatible scenarios modelled by the IPCC, the Met Office said. BLOOMBERG