The table shows the carbon dioxide concentration of the atmosphere and the global temperature difference from a long-term average in five years.
| Year | Carbon dioxide / ppm | Temperature difference / ∘C^\circ\mathrm{C}∘C |
|---|---|---|
| 1880 | 291 | -0.17 |
| 1920 | 303 | -0.27 |
| 1960 | 317 | -0.03 |
| 2000 | 370 | +0.39 |
| 2020 | 414 | +1.01 |
Statement 1: Overall, the data show a positive correlation between carbon dioxide concentration and temperature difference.
Statement 2: The value for 1880 is likely to be less certain than the value for 2020, as fewer measurements were made in fewer places.
Statement 3: The data prove that the rise in carbon dioxide concentration caused the rise in temperature.
Which statements are correct?
1 only
2 and 3 only
1 and 2 only
1, 2 and 3
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.