The current concentration of carbon dioxide (CO₂) in Earth’s atmosphere is 0.0421%, and 30 years ago, in 1993, it was approximately 0.0357%. This represents a 0.0064 percentage point increase in CO₂ levels over the past 30 years  .

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The concentration of carbon dioxide (CO₂) in Earth’s atmosphere is currently 0.0421 (421 parts per million) as of 2022. Thirty years ago, in 1993, it was approximately 0.0357 (357 parts per million). This marks an increase of about 0.0064, or a 0.64% rise in terms of parts per million over that period  .