Levels of carbon dioxide (CO2) in our atmosphere surged to unprecedented heights in 2024, according to scientists, jeopardizing international efforts to curb global warming. As the world experiences its hottest year on record, CO2 concentrations rise more than 50% above pre-industrial levels due to an unprecedented spike in fossil fuel emissions and diminishing natural carbon absorption.
Preliminary data reveals that last year set record highs for fossil fuel emissions, as wildfires and drought complicated the climate system’s ability to absorb CO2. The rapid rise in CO2 is "incompatible" with the global ambition pledged at the 2015 UN Paris agreement, aimed at limiting climate change to a 1.5C increase above pre-industrial levels.
2024 is noted as the first entire calendar year to exceed average temperatures of 1.5C above those historical levels, although this does not officially breach the Paris agreement's long-term goals. Richard Betts from the Met Office emphasized that the CO2 increase is exacerbating the climate crisis, as objectives to limit warming require a deceleration in CO2 growth.
Historical records indicate that current CO2 levels are at their highest in at least two million years, which scientists attribute primarily to human-induced factors, such as fossil fuel combustion and deforestation. Changes in the natural world's capacity to absorb CO2, affected by phenomena like El Niño, have further worsened the situation.
CO2 concentrations skyrocketed by nearly 3.6 parts per million (ppm) between 2023 and 2024, peaking at over 424 ppm, marking the largest annual increase since atmospheric monitoring began in 1958 at the Mauna Loa observatory. These results indicate that we’re advancing into unprecedented climate conditions more rapidly than anticipated.
The increase raises alarming concerns about the sustainability of the Earth's carbon sinks, particularly as the Arctic tundra transforms into a CO2 source from warming and fire impacts. The Amazon rainforest, also suffering from drought and deforestation, faces diminished capacity to absorb greenhouse gases.
Looking ahead, the Met Office forecasts a less severe increase in CO2 levels in 2025. However, prevailing conditions remain starkly misaligned with the targets necessary to combat climate change. While La Niña conditions may temporarily favor CO2 absorption, experts caution that the underlying trajectory of climate change continues to build as CO2 accumulates in the atmosphere.
