Question

round 1: living things and the atmosphere
first stop: the atmosphere
earths atmosphere is composed of many different gasses. many people think that air is strictly oxygen, but it is actually much more than that. the air that we breathe is 78% nitrogen, 21% oxygen, 1% other gasses. in fact only 0.04% of the air we breathe is composed of carbon dioxide! in comparison, thats as if you had $100 and only 4 cents of it was carbon dioxide. despite the fact that carbon dioxide is such a small amount, it plays a large part in our climate, as it is a greenhouse gas. greenhouse gasses insulate the earth, so if there are more greenhouse gasses, the temperature of the earth will increase. carbon dioxide is a gas, and it is often written as co₂, which means it is composed of one carbon atom and 2 oxygen atoms.
diagram: color the cloud representing the atmosphere gray (light gray, so you can still read the writing).
questions:

1. what percentage of the earths atmosphere is made of carbon dioxide?
2. why is carbon dioxide considered a greenhouse gas?

Explanation:

1. The text directly states the percentage of carbon dioxide in the air we breathe.
2. The text explains the role of greenhouse gases like carbon dioxide in insulating the Earth.

Answer:

1. 0.04%
2. Because it plays a large part in our climate as it is a greenhouse gas that insulates the Earth.