Read the excerpt from "Climate Change: An Overview.” By the early twentieth century, carbon emissions from fossil-fuel burning reached 1 billion tons a year. Automobiles, airplanes, and domestic and agricultural energy demands all contributed to the rising trend. In the 1950s, scientists used a new generation of equipment to confirm that carbon-dioxide concentrations were doubling and that this would have the effect of increased temperatures. What chronology is described in this excerpt?
Answer
A
the development of new technologies from the early twentieth century through the 1950s
B
the changes in popular modes of transportation from the early twentieth century through the 1950s
C
the increase in automobile usage from the early twentieth century through the 1950s
D
the changes in carbon dioxide emissions from the early twentieth century through the 1950s
Explanation
The excerpt first describes carbon emissions reaching 1 billion tons a year by the early twentieth century, then explains that scientists in the 1950s confirmed rising carbon-dioxide concentrations. This sequence shows changes in carbon dioxide emissions and concentrations over time, so the best choice is “the changes in carbon dioxide emissions from the early twentieth century through the 1950s.”
AI-written and checked against the verified answer.