Carbon dioxide and global warming: the greenhouse effect
3 marks · EasyBelow is a table showing average yearly global CO2 concentrations for three years:
| Year | CO2 concentration (ppm) |
|---|---|
| 2000 | 370 |
| 2010 | 390 |
| 2020 | 415 |
Describe the trend shown by the data.
Calculate the average increase in CO2 concentration per decade over the period 2000–2020.
State one possible environmental consequence of this trend.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) The CO2 concentration is increasing each decade
(b) 22.5 ppm/decade
(c) Rising sea levels
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Clearly describes that CO2 concentration increases over the years.
M1 (b) · 1 mark · Correct calculation: (415-370)/2 = 45/2 = 22.5 ppm per decade
B1 (c) · 1 mark · States an environmental consequence (e.g. global warming, climate change, rising sea levels, melting ice, extreme weather)
Worked solution
a) The concentration of CO2 is rising in each ten-year period.
b) Average increase per decade = (415 - 370) / 2 = 45 / 2 = 22.5 ppm per decade.
c) Possible consequence: melting of polar ice caps / global warming / rising sea levels.