Background: Carbon dioxide is the most significant long-lived greenhouse gas in Earth's atmosphere. Since the Industrial Revolution anthropogenic emissions – primarily from use of fossil fuels and deforestation – have rapidly increased its concentration in the atmosphere, leading to global warming.  Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid.

Situation: Milton has just discovered two new planets while looking through his telescope. Luckily, he has invented a device that allows him to analyze far away planets from the comfort of his own home. He boots up the device and discovers that while these two planets are very similar, planet A has much more carbon dioxide in its atmosphere than planet B. While looking through his telescope, he is also able to see that there is the same race of intelligent creatures on both planets. Milton plans to write to his local observatory about his discovery.

Question: Which planet is experiencing more global warming?
Answer: planet A

Situation: Milton has just discovered two new planets while looking through his telescope. Luckily, he has invented a device that allows him to analyze far away planets from the comfort of his own home. He boots up the device and discovers that while these two planets are very similar, planet A has much more carbon dioxide in its atmosphere than planet B. While looking through his telescope, he is also able to see that there is the same race of intelligent creatures on both planets. Milton plans to write to his local observatory about his discovery.

Question: Which planet is experiencing less global warming?
Answer: planet B

Situation: Milton has just discovered two new planets while looking through his telescope. Luckily, he has invented a device that allows him to analyze far away planets from the comfort of his own home. He boots up the device and discovers that while these two planets are very similar, planet A has much more carbon dioxide in its atmosphere than planet B. While looking through his telescope, he is also able to see that there is the same race of intelligent creatures on both planets. Milton plans to write to his local observatory about his discovery.

Question: Which planet probably has less trees?
Answer: planet A

Situation: Milton has just discovered two new planets while looking through his telescope. Luckily, he has invented a device that allows him to analyze far away planets from the comfort of his own home. He boots up the device and discovers that while these two planets are very similar, planet A has much more carbon dioxide in its atmosphere than planet B. While looking through his telescope, he is also able to see that there is the same race of intelligent creatures on both planets. Milton plans to write to his local observatory about his discovery.

Question: Which planet probably has more trees?
Answer: planet B

Situation: Milton has just discovered two new planets while looking through his telescope. Luckily, he has invented a device that allows him to analyze far away planets from the comfort of his own home. He boots up the device and discovers that while these two planets are very similar, planet A has much more carbon dioxide in its atmosphere than planet B. While looking through his telescope, he is also able to see that there is the same race of intelligent creatures on both planets. Milton plans to write to his local observatory about his discovery.

Question: Is it more likely that the creatures on planet A or planet B use fossil fuels for energy?
Answer: planet A

Situation: Milton has just discovered two new planets while looking through his telescope. Luckily, he has invented a device that allows him to analyze far away planets from the comfort of his own home. He boots up the device and discovers that while these two planets are very similar, planet A has much more carbon dioxide in its atmosphere than planet B. While looking through his telescope, he is also able to see that there is the same race of intelligent creatures on both planets. Milton plans to write to his local observatory about his discovery.

Question: Is it less likely that the creatures on planet A or planet B use fossil fuels for energy?
Answer: planet B

Situation: Milton has just discovered two new planets while looking through his telescope. Luckily, he has invented a device that allows him to analyze far away planets from the comfort of his own home. He boots up the device and discovers that while these two planets are very similar, planet A has much more carbon dioxide in its atmosphere than planet B. While looking through his telescope, he is also able to see that there is the same race of intelligent creatures on both planets. Milton plans to write to his local observatory about his discovery.

Question: Is the amount of carbonic acid in planet A's oceans higher or lower than planet B's oceans?
Answer: higher

Situation: Milton has just discovered two new planets while looking through his telescope. Luckily, he has invented a device that allows him to analyze far away planets from the comfort of his own home. He boots up the device and discovers that while these two planets are very similar, planet A has much more carbon dioxide in its atmosphere than planet B. While looking through his telescope, he is also able to see that there is the same race of intelligent creatures on both planets. Milton plans to write to his local observatory about his discovery.

Question: Is the amount of carbonic acid in planet B's oceans higher or lower than planet A's oceans?
Answer: lower

Situation: Milton has just discovered two new planets while looking through his telescope. Luckily, he has invented a device that allows him to analyze far away planets from the comfort of his own home. He boots up the device and discovers that while these two planets are very similar, planet A has much more carbon dioxide in its atmosphere than planet B. While looking through his telescope, he is also able to see that there is the same race of intelligent creatures on both planets. Milton plans to write to his local observatory about his discovery.

Question: Do the inhabitants of planet B probably produce more or less anthropogenic emissions than planet A?
Answer: less

Situation: Milton has just discovered two new planets while looking through his telescope. Luckily, he has invented a device that allows him to analyze far away planets from the comfort of his own home. He boots up the device and discovers that while these two planets are very similar, planet A has much more carbon dioxide in its atmosphere than planet B. While looking through his telescope, he is also able to see that there is the same race of intelligent creatures on both planets. Milton plans to write to his local observatory about his discovery.

Question: Do the inhabitants of planet A probably produce more or less anthropogenic emissions than planet B?
Answer: more