Carbon dioxide is one of the greenhouse gases blamed for the rise in Earth's global temperature. Since the Industrial Revolution, human activities have raised atmospheric carbon dioxide levels by 50%.
Despite various efforts to curb CO2 emissions in the atmosphere, a recent observation has unveiled a disconcerting truth-this greenhouse gas is accumulating at an unprecedented rate, underscoring the urgent need for immediate action.
A Disturbing Discovery
Last March, the monthly average concentration of CO2 was 4.7 parts per million (ppm) higher than in March 2023, reaching a record 425.22 ppm. This has been the largest annual leap ever measured at the Mauna Loa Observatory, the National Oceanic Atmospheric Administration (NOAA) laboratory atop a volcano on Hawaii's Big Island.
From January through April, carbon dioxide levels increased faster than they have in the first quarter of any other year. This was the latest record in a 66-year-long series of atmospheric observations.
Carbon dioxide concentrations at Mauna Loa in May have broken previous records for several decades. The recent increase in atmospheric carbon dioxide surpassed a record-setting acceleration observed in 2016.
Experts interpret this data as a stark reminder of humanity's failure to curb global greenhouse gas emissions. As climate scientist Arlyn Andrews from NOAA's Global Monitoring Laboratory warns, not only is carbon dioxide still on the rise in the atmosphere, but it is also accelerating. This trend, as Scripps Institution CO2 Program director Ralph Keeling points out, is a direct consequence of our increased reliance on fossil fuels.
Every year, carbon dioxide levels naturally ebb and flow. At Mauna Loa, these levels peak in April and May and decline until August and September. This follows the growth cycle of plants in the northern hemisphere, where they grow and sequester away carbon during the summer months and release it during fall and winter as they die and decompose. Once carbon dioxide reaches the atmosphere, it stays there for hundreds of years and acts as a blanket that traps heat.
Role of El Niño in Rising CO2 Levels
The increase in CO2 levels is not precisely consistent. The historically strong El Niño climate pattern developed last year is a significant factor for this spike.
El Niño is connected to warmer-than-average surface waters along the equator in the central and eastern Pacific. This warmth affects the weather patterns around the globe and triggers extreme heat, floods, and droughts. In particular, droughts contribute to higher-than-normal spikes in atmospheric CO2.
Tropical forests are considered reliable stores of carbon since they do not undergo the same seasonal decay as plant life found at higher altitudes. However, droughts in tropical areas related to El Niño mean less carbon storage within plants, according to Keeling. Andrews also added that global land-based ecosystems seem to give off more CO2 during El Niño due to the changes in temperature and precipitation brought by the weather pattern.
This enables carbon dioxide concentrations to rise quickly at the end of El Niño events. Similarly, a record surge in CO2 concentrations in early 2016 was also observed at the end of a historically strong El Niño.
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