Which of the following statements about carbon dioxide concentrations is true?
A) They show no seasonality; they increase more or less linearly.
B) They are highest in the summer, because high temperatures accelerate metabolism.
C) They are highest in the spring and fall, coinciding with upwelling.
D) They are highest in the winter, because winter photosynthesis rates are lower than winter respiration rates.
E) They are highest in the winter, because air is densest in the winter.

Question

Quizplus · Accepted Answer

Carbon dioxide concentrations are highest in the winter because photosynthesis rates are lower than respiration rates during this time, leading to an accumulation of CO2 in the atmosphere.

Which of the Following Statements About Carbon Dioxide Concentrations Is