The rate of CO2 emissions for the UK was measured every 5 years, from 1990 to 2015.
The results are given in the table below with the rate of CO2 emissions measured in x109 kg year-1
Rate of CO2 emissions (x109 kg year-1)
Using all of this information,
a) Estimate the total CO2 emissions from the UK between 1990 and 2015, giving your answer in standard form.
Given that the curve produced by plotting a graph of the rate of CO2 emissions against the year is concave,
b) Explain whether your answer to part (a) is an underestimate or an overestimate of the total CO2 emissions between 1990 and 2015.