The table shows information about three greenhouse gases.
| Gas | Increase in concentration since 1750 (parts per billion) | Warming effect of one molecule compared with one molecule of carbon dioxide |
|---|---|---|
| Carbon dioxide | 140 000 | 1 |
| Methane | 1 200 | 25 |
| Nitrous oxide | 60 | 220 |
Which gas has caused the most extra warming since 1750, and why?
Methane, because each methane molecule has a warming effect 25 times greater than a carbon dioxide molecule.
Nitrous oxide, because each molecule has the largest warming effect.
Carbon dioxide, because its increase in concentration is so much greater that it outweighs its smaller warming effect per molecule.
All three gases have caused the same extra warming, because the gases with smaller increases have larger warming effects per molecule.
109 exam-style questions on OCR GCSE Chemistry 6.3 Interpreting and interacting with earth systems, covering 6.3.1 Formation and evolution of the atmosphere, 6.3.2 The greenhouse effect and climate change, 6.3.3 Sources and problems of atmospheric pollutants, and 6.3.4 Producing potable water. Each one has a worked solution and a mark scheme showing where the marks go.