Question

Volcanoes on Earth are constantly pumping CO2 into the atmosphere. What happens to that CO2 to prevent it from building up over long (million-year) timescales?

(a) It dissolves into water vapor in the air, rains into the oceans, is turned into rock, and carried back into the Earth by plate tectonics.
(b) It is heated by ultraviolet rays from the Sun and broken apart into C and O2. The light C atoms escape into space and the O2 is breathed by animals.
(c) It is absorbed by rocks on Earth's continents and reacts with them chemically to become oil and natural gas.
(d) It is absorbed by plants, which then die and become fossils, recycling the carbon back into the ground.
(e) It reacts with chemicals such as nitrogen and sulfur in Earth's atmosphere and produces acid rain.

Answer 1

CO2 from volcanic activity is prevented from building up over long timescales by dissolving into the oceans, turning into rock through geological processes, and being subducted back into the Earth. Photosynthesis, respiration, and fossilization also play crucial roles in the carbon cycle.

Step-by-step explanation:

Volcanoes on Earth indeed contribute to atmospheric CO2, but long-term geological and biological processes prevent its buildup over millions of years. The correct answer to what happens to CO2 to prevent it from building up over long timescales is (a) It dissolves into water vapor in the air, rains into the oceans, is turned into rock, and carried back into the Earth by plate tectonics. This is part of a larger carbon cycle where carbon dioxide is absorbed by ocean water and can eventually settle to form fossil fuels or sedimentary rocks to store carbon for millions of years. In addition, living organisms play a critical role in cycling CO2 through processes like photosynthesis and respiration. Dead organisms contribute to carbon storage when they are buried and fossilized, and geological processes like volcanic eruptions can liberate this stored carbon back into the atmosphere.