Multiple choice general knowledge

What is the acceptable level of CO2 in the atmosphere

  1. 400 PPM

  2. 350 PPM

  3. 300 PPM

  4. 375 PPM
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

350 PPM (parts per million) is considered the safe upper limit for CO2 concentration in the atmosphere to maintain climate stability. Beyond this level, risks of dangerous climate change increase significantly. The question reflects climate science concerns from the 2000s when this target was actively discussed. Current levels exceed 400 PPM.

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