A steady increase in global temperature has been recorded between 1900 and today. Before concluding that this rise in
temperature is the result of the increased burning of fossil
fuels since that same time, which of the following questions
would have to be answered?

A What is the CO2 content in one metric ton of fossil
fuels?
B Which gases are released when burning fossil fuels?
C What, if any, temperature rise was occurring prior to
1900?
D How have humans adapted to temperature change?