GRE Reading Comprehension: ETS-GRE阅读ETS - 4C577SM43Q27ZJOQ7

According to the passage, which of the following statements best describes the relationship between carbon dioxide and global temperature? A. Carbon dioxide levels change immediately in response to changes in temperature. B. Carbon dioxide levels correlate with global temperature during cooling periods only. C. Once carbon dioxide levels increase, they remain high regardless of changes in global temperature. D. Carbon dioxide levels increase more quickly than global temperature does. E. During cooling periods, carbon dioxide levels initially remain high and then decline.