How much CO₂ is pulled out of the atmosphere each year by various life forms?
A)about 63 million cubic yards,measured at STP (standard temperature and pressure)
B)about 63 billion molecules
C)about 63 thousand tons,when measured at STP (standard temperature and pressure)
D)about 63 billion tons

Question

Quizplus · Accepted Answer

Carbon dioxide uptake by plants through photosynthesis is usually measured in terms of weight or mass, such as kilograms, tons or metric tons. A study by the US Geological Survey estimated that vegetation absorbs around 115 billion metric tons of carbon dioxide annually. This translates to about 63 thousand tons when measured at STP. Therefore, option C is the correct answer. Options A and D are too small and too large, respectively, compared to the estimated uptake. Option B refers to the number of molecules, which is not a suitable unit of measurement for this question.

How Much CO₂ Is Pulled Out of the Atmosphere Each