Planet-warming carbon dioxide levels rose more than ever in 2024

Levels of the world’s most important greenhouse gas in the atmosphere rose faster than ever recorded last year, scientists say, leaving a major global goal hanging by a thread.

Carbon dioxide (CO2) emissions are now 50% higher than before humans started burning more fossil fuels.

Last year, fossil fuels were at an all-time high, as the environment struggled to absorb more CO2 from events such as wildfires and droughts, which caused severe disruption in the atmosphere.

The rapid increase in CO2 is “not compatible” with the global pledge to limit global warming to 1.5C above pre-industrial levels, the Met Office says.

This was the main goal that nearly 200 countries agreed to at the UN special meeting in Paris in 2015, in the hope of avoiding further problems of climate change.

Last week it was confirmed that 2024 was the hottest year on recordit is the first calendar year in which the average annual temperature was more than 1.5C above pre-industrial levels.

This has not breached the Paris target, which refers to a long-term increase over several decades, but the continued increase in CO2 emissions will cause the world to do so.

Richard Betts of the Met Office said: “Limiting global warming to 1.5C may require a reduction in CO2 emissions, but the reality is that the opposite is happening.

The long-term increase in CO2 is undoubtedly the result of human activities, particularly the use of coal, oil and gas, and deforestation.

Records of Earth’s past climate from ice and sea sediments show that CO2 levels are currently the highest in at least two million years, according to the UN.

But the increase varies from year to year, due to differences in the way natural resources absorb carbon, and the variability of human emissions.

Last year, CO2 emissions from fossil fuels reached a new high, according to the Global Carbon Project.

There were also results of natural El Niño phenomenon – Where the surface waters of the eastern Pacific Ocean are unusually warm, which affects the weather.

Environments account for almost half of the CO2 emissions that humans emit, for example due to the growth of crops and the excess carbon dioxide that dissolves in the oceans.

But the increased warming from El Niño versus climate change meant that natural gas emissions on land did not absorb as much CO2 as usual last year.

Wildfires, including areas not affected by El Niño, also released more CO2.

“Even without the boost from last year’s El Niño, CO2 emissions driven by fossil fuel burning and deforestation would have continued to increase. [UN climate body] IPCC’s 1.5C scenario,” says Prof Betts.

This means that between 2023 and 2024 CO2 levels will rise by about 3.6 parts per million (ppm) molecules of air to a new high of over 424ppm.

This is the largest annual increase since atmospheric measurements were first taken at the remote Mauna Loa observatory in Hawaii in 1958. Being located on the edge of a volcano in the Pacific Ocean, its remote location away from major pollution sites makes it ideal. monitoring global CO2 emissions.

“These latest results confirm that we are moving rapidly into an area that has never been measured before in terms of rising tides,” says Prof Ralph Keeling, who heads the measurement program at the Scripps Institution of Oceanography in the US.

This record increase is fueling concern that over time, natural resources will not be able to absorb global warming.

The Arctic tundra is being turned into a complete source of CO2, due to heat and frequent fires, according to the US science group NOAA.

The the ability of the Amazon rainforest to absorb CO2 it is also affected by drought, wildfires and deforestation.

“It’s an open question, but it’s something we have to look at and look at carefully,” Prof Betts told the BBC.

The Met Office predicts that CO2 emissions in 2025 will be lower than in 2024, but still not well on track to meet the 1.5C target.

La Niña conditions – where the waters of the eastern Pacific Ocean are cooler than normal – are replacing El Niño, which allow the environment to absorb more CO2.

“Even though there may be a temporary cooling off, the warming will resume as CO2 continues to build up in the atmosphere,” says Prof Betts.