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Record Levels of Atmospheric CO2 Raise Concerns Over Climate Goals
June saw parts of India suffering under an intense heatwave, contributing to what has been identified as the hottest year recorded globally.
Scientists have reported that levels of carbon dioxide (CO2), the primary greenhouse gas responsible for global warming, experienced the most rapid increase ever documented last year. This alarming trend threatens to undermine crucial international climate objectives.
Data shows that atmospheric CO2 concentrations have risen over 50% since the onset of large-scale fossil fuel combustion. The continuous rise in emissions from fossil fuels reached unprecedented heights last year, coinciding with the natural world’s diminished capacity to absorb CO2, affected by factors such as drought and rampant wildfires. Consequently, more CO2 has remained trapped in the atmosphere.
The UK Met Office has declared that the swift CO2 increase is “incompatible” with the collective pledge by nearly 200 nations to limit global warming to 1.5°C above pre-industrial levels. This target, established during the landmark 2015 UN Paris Agreement, aimed to alleviate some of the severe consequences of climate change.
Recent confirmation revealed that 2024 marked the highest temperatures recorded, with annual averages surpassing the 1.5°C threshold for the first time. However, it is essential to note that this doesn’t invalidate the Paris Agreement’s long-term goal, which focuses on a multi-decade average.
Richard Betts from the Met Office explains that to meet the 1.5°C goal, CO2 levels would need to stabilize or decrease, yet the current trends present the opposite situation.
The ongoing increase in CO2 levels can be directly linked to human activities, particularly the combustion of fossil fuels and deforestation. Historical climate records from sources like ice cores indicate that the current CO2 levels have not been seen for at least two million years.
The rise in CO2 levels has exhibited annual variations influenced by how nature absorbs carbon and changes in human emissions. Last year, emissions from fossil fuels reached record levels, exacerbated by the El Niño phenomenon, which resulted in warmer surface waters in the eastern tropical Pacific Ocean and subsequently impacted global weather patterns.
While natural processes have absorbed approximately half of humanity’s CO2 emissions, including enhanced plant growth and ocean absorption, the intensity of the past year’s El Niño, compounded by climate change, hindered natural carbon sinks from effectively capturing CO2 as they typically would.
The surge in emission levels has also been fueled by widespread wildfires, particularly in regions that do not usually experience significant impacts from El Niño.
Professor Betts warns that even without the influence of El Niño, the rise in CO2 driven by fossil fuel combustion and deforestation would outpace the scenarios laid out by the Intergovernmental Panel on Climate Change (IPCC) concerning the 1.5°C target.
This accumulation enabled CO2 levels to soar by nearly 3.6 parts per million (ppm) from 2023 to 2024, reaching an unprecedented high of over 424 ppm. This figure represents the most significant annual increase since CO2 measurements began at the remote Mauna Loa research station in Hawaii in 1958, a site chosen for its ability to provide reliable data free from local pollution.
Professor Ralph Keeling from the Scripps Institution of Oceanography noted, “These latest results further confirm that we are moving into uncharted territory faster than ever as the rise continues to accelerate.”
In addition to emissions concerns, the ability of natural ecosystems to absorb CO2 is being jeopardized. Drought, wildfires, and purposeful deforestation have diminished the Amazon rainforest’s capability to sequester CO2.
According to NOAA, the Arctic tundra is shifting to become a source of CO2 due to warming and increased fire activity, further complicating the climate landscape. Moreover, the Amazon’s CO2 absorption is similarly threatened by these alarming environmental changes, leaving its future effectiveness as a carbon sink in question.
Looking ahead, the Met Office anticipates that the rise in CO2 levels in 2025 will not be as pronounced as in 2024 but will still fall significantly short of achieving the 1.5°C objective.
Current La Niña conditions may provide temporary relief, promoting natural systems to absorb more CO2, contrasting with the warming trend associated with El Niño. However, Professor Betts emphasizes that irrespective of these fluctuations, the accumulation of CO2 is set to continue.
Source
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