Some scientists believe that greenhouse gas emissions from transportation are a major contributor to global climate change.
The graph below shows the relative carbon dioxide (CO2\text{CO}_2CO2) emissions from the transportation sector in the United States and the relative change in global average surface temperature between the years 2000 and 2020.

Evaluate the information shown in the graph. To what extent does the graph support a link between emissions from transportation and global warming?
Suggest two problems with using information about US transport CO2\text{CO}_2CO2 emissions to draw conclusions about global temperature changes.
Describe one effect of global warming on the environment, other than rising average surface temperatures.
Suggest one way human activity can be modified to reduce carbon dioxide emissions from transportation.