Atmospheric carbon dioxide concentrations:
A)have decreased over the last few decades.
B)increase with height above the tropopause.
C)have not been reliably measured for the northern hemisphere.
D)are highest in early spring.

Question

Atmospheric carbon dioxide concentrations: 
A)have decreased over the last few decades.
B)increase with height above the tropopause.
C)have not been reliably measured for the northern hemisphere.
D)are highest in early spring.

Quizplus · Accepted Answer

Atmospheric carbon dioxide concentrations are highest in early spring. This is because during winter, photosynthesis slows down due to the absence of leaves on many plants, especially in the northern hemisphere, which has a significant impact on global carbon cycles. This leads to less carbon dioxide being absorbed from the atmosphere. The concentrations start to decrease as spring progresses into summer because plants begin to grow leaves and actively absorb more CO2 for photosynthesis.

Atmospheric Carbon Dioxide Concentrations