The study looked at why atmospheric carbon dioxide levels have been rising quickly between 1980 and 2007. They wanted to see if human carbon dioxide emissions or global temperatures were the main reason for this increase. Many people think that more emissions mean more carbon dioxide in the air, but the researchers found that higher temperatures were the key factor. Surprisingly, even though global warming is happening, the amount of carbon dioxide staying in the atmosphere is actually decreasing. This drop might be because more carbon dioxide is being soaked up by plants and the oceans due to the higher amount of carbon dioxide in the air.