Record Greenhouse Gas Levels in 2023

In October 2024, the World Meteorological Organization (WMO) reported a record-breaking rise in greenhouse gas (GHG) levels in 2023, with carbon dioxide (CO2) concentrations reaching a critical high of 420 ppm, indicating severe climate risks.

Key Points

CO2 Comparison: Current CO2 levels mirror conditions last seen 3-5 million years ago, a period with significantly warmer temperatures and sea levels up to 20 meters higher than today.
GHG Concentrations in 2023: The year marked the 12th consecutive annual increase in CO2 levels, with a notable rise of 2.3 ppm over the previous year, driven by factors including fossil fuel emissions, reduced forest carbon absorption, and large-scale vegetation fires.
El Niño’s Role: The 2023 El Niño event intensified emissions due to reduced rainfall and increased wildfires. WMO explained that the drier vegetation in such years reduces the capacity of natural carbon sinks, worsening the GHG levels.
Potential Vicious Cycle: WMO scientists warned of a looming “vicious cycle,” where climate change might turn ecosystems from GHG absorbers to emitters, further accelerating global warming.
Long-term Warming Effect: According to NOAA’s data, radiative forcing from long-lived GHGs surged by 51.5% since 1990, with CO2 contributing over 81% of this effect.
Methane’s Alarming Rise: Methane, the second most impactful GHG, saw its highest three-year increase between 2020 and 2022, largely due to increased emissions from natural wetlands during the La Niña events, highlighting risks from climate variability.