CO2 levels in Earth’s atmosphere jumped by a record amount in 2024

The United Nations’ World Meteorological Organization (WMO) reported an unprecedented rise in atmospheric carbon dioxide levels in 2024, marking the highest concentrations since record-keeping commenced.

From 2023 to 2024, the global average CO2 concentration soared by 3.5 parts per million (ppm), reaching 423.9 ppm. This marks the most significant increase since 1957, surpassing the 2.3 ppm rise observed from 2022 to 2023.

This rise fits into a continuing trend of increasing annual CO2 levels, with the rate of increase having tripled since the 1960s. The last time atmospheric levels were comparable to those now was between 3 million and 5 million years ago.

According to the WMO, elevated CO2 levels will warm the planet for many centuries. “The heat trapped by CO2 and other greenhouse gases is supercharging climate change and leading to increasingly severe weather conditions,” noted Ko Barrett from the WMO.

This record increase in CO2 is mainly attributed to ongoing fossil fuel emissions, a significant rise in emissions from wildfires, and a reduction in carbon absorption by the planet’s lands and oceans, as outlined by the WMO.

In 2024, scientists predicted a drop in carbon absorption by oceans, forests, and ecosystems, influenced by the current El Niño weather pattern, which has raised global temperatures while inhibiting carbon storage due to heat, fires, and drought in crucial areas such as the Amazon. Earlier this year, researchers noted that the loss of tropical forest cover in 2024 was twice that of 2023, and as Richard Allan from the University of Reading, UK, explained, “It’s typical for certain tropical regions to experience dryness and reduce carbon storage during warmer El Niño years like 2024.”

However, there are fears that this decline in carbon absorption—particularly on land—may be indicative of a longer-term trend suggesting that climate change is impairing the planet’s capacity to absorb excess carbon.

“There are concerns that the land carbon sink has been notably low in 2023 and 2024, particularly for El Niño years, indicating a worrying decline over an extended period, mainly affecting regions in the northern hemisphere outside the tropics,” explained Zeke Hausfather, a climate scientist at the Breakthrough Institute. “In summary, we are witnessing troubling indications that the land carbon sink is on the decline, though it is premature to draw definitive conclusions without additional data over the coming years.”

In the face of this situation, it is increasingly critical for humanity to reduce fossil fuel emissions, emphasized Piers Forster at the University of Leeds, UK. “The main factor driving the ongoing rise in CO2 concentrations is the unrelenting high levels of fossil fuel emissions that have yet to decline.”