The concentration of carbon dioxide (CO2), the leading planet-warming gas in Earth’s atmosphere, has risen faster than ever before, according to recent scientific data. This alarming trend underscores the urgent challenges of meeting global climate targets, including the goal of limiting global warming to 1.5°C above pre-industrial levels.
CO2 concentrations are now over 50% higher than levels recorded before industrialization. In 2024, emissions from fossil fuels reached unprecedented heights, while natural carbon sinks such as forests and oceans struggled to absorb the excess. Factors such as wildfires, droughts, and the El Niño phenomenon compounded the issue, leaving more CO2 to accumulate in the atmosphere.
Richard Betts of the UK Met Office highlighted the severity of the situation: “Limiting global warming to 1.5°C requires the rate of CO2 increase to slow down, but we are witnessing the opposite.”
Last year marked the first calendar year where average global temperatures exceeded 1.5°C above pre-industrial levels, though this measurement reflects short-term fluctuations rather than the long-term averages defined by the Paris Agreement. However, rising CO2 levels make it increasingly likely that this threshold will be consistently breached, with dire implications for ecosystems, weather patterns, and human communities.
The record CO2 levels rising nearly 3.6 parts per million (ppm) in just a year to exceed 424 ppm are primarily driven by human activities, including the burning of fossil fuels and deforestation. However, natural phenomena such as El Niño also played a role. El Niño conditions, characterized by warmer-than-average Pacific Ocean temperatures, weakened natural carbon sinks and contributed to widespread wildfires, releasing even more CO2.
Long-term changes are also diminishing the Earth’s ability to absorb CO2. The Amazon rainforest, often referred to as the “lungs of the planet,” is struggling under the combined pressures of drought, wildfires, and deforestation. Similarly, Arctic tundra regions are becoming net sources of CO2 due to warming and more frequent fires.
Scientists warn that even with the shift to La Niña conditions, which could improve natural CO2 absorption, current emission levels remain far off track for meeting the 1.5°C target. “We’re venturing into uncharted territory at an alarming pace,” said Professor Ralph Keeling of the Scripps Institution of Oceanography.
The challenges posed by rising CO2 levels demand immediate and sustained global action. Investments in renewable energy, reforestation, and sustainable practices are critical to reversing these trends. While the situation is dire, there is still a narrow window to act and prevent the worst impacts of climate change.
