Background: Because of human activities, there is more carbon dioxide in the atmosphere today than in the past hundreds of thousands of years. Burning fossil fuels and has released great quantities of carbon dioxide into the atmosphere. Cutting forests and clearing land has also increased carbon dioxide into the atmosphere because these activities reduce the number of autotrophic organisms that use up carbon dioxide in photosynthesis. In addition, clearing often involves burning, which releases carbon dioxide that was previously stored in autotrophs.

Situation: There are two exact copies of planets, including the animals and plants on each planet. The only difference between these two planets, Necrulon and Krankor, is their choice of transportation. On Necrulon, they use fossil fuels to move their vehicles, and on Krankor they use water.

Question: Which planet has more carbon dioxide in the atmosphere?
Answer: Necrulon

Situation: There are two exact copies of planets, including the animals and plants on each planet. The only difference between these two planets, Necrulon and Krankor, is their choice of transportation. On Necrulon, they use fossil fuels to move their vehicles, and on Krankor they use water.

Question: Which planet has less carbon dioxide in the atmosphere?
Answer: Krankor

Situation: There are two exact copies of planets, Necrulon and Krankor, including the animals and plants on each planet. Recently though, people on Krankor have been wanting to have more space for new buildings. In order to accommodate these new buildings, they have started to cut forests and clear land. The people on Necrulon, however, decided to keep their forests and land rather than further industrialize.

Question: Does Krankor have more or less autotrophic organisms than Necrulon?
Answer: less

Situation: There are two exact copies of planets, Necrulon and Krankor, including the animals and plants on each planet. Recently though, people on Krankor have been wanting to have more space for new buildings. In order to accommodate these new buildings, they have started to cut forests and clear land. The people on Necrulon, however, decided to keep their forests and land rather than further industrialize.

Question: Does Necrulon have more or less autotrophic organisms than Krankor?
Answer: more

Situation: There are two exact copies of planets, Necrulon and Krankor, including the animals and plants on each planet. Recently though, people on Krankor have been wanting to have more space for new buildings. In order to accommodate these new buildings, they have started to cut forests and clear land. The people on Necrulon, however, decided to keep their forests and land rather than further industrialize.

Question: Photosynthesis will be used more on which planet?
Answer: Necrulon

Situation: There are two exact copies of planets, Necrulon and Krankor, including the animals and plants on each planet. Recently though, people on Krankor have been wanting to have more space for new buildings. In order to accommodate these new buildings, they have started to cut forests and clear land. The people on Necrulon, however, decided to keep their forests and land rather than further industrialize.

Question: Photosynthesis will be used less on which planet?
Answer: Krankor