The concentration of carbon dioxide in the Earth's atmosphere is commonly measured in parts per million (ppm).
The table below shows the average concentration of carbon dioxide in the atmosphere in October 2005 and in October 2023.
| Date | Concentration of carbon dioxide in ppm |
|---|---|
| October 2005 | 379.82 |
| October 2023 | 420.46 |
Calculate the increase in the concentration of carbon dioxide in the atmosphere, in ppm, from October 2005 to October 2023.
Give your answer to the nearest whole number.
97 exam-style questions on Edexcel GCSE Chemistry 9.2 Earth and atmospheric science, covering 9.2.1 The Earth's early atmosphere, 9.2.2 How the atmosphere evolved, 9.2.3 Chemical test for oxygen, and 9.2.4 The greenhouse effect and climate change. Each one has a worked solution and a mark scheme showing where the marks go.