Governments are looking for ways to reduce the effect of greenhouse gases on the climate.
In 1750 the concentration of carbon dioxide in the atmosphere was 280 ppm. In 2020 it was 414 ppm and was increasing by about 2 ppm each year.
Calculate the year in which the concentration of carbon dioxide will be double its 1750 value if it continues to increase at this rate.
Over a 100-year period, one molecule of methane causes about 30 times as much warming as one molecule of carbon dioxide. Suggest why cutting methane emissions is seen as a quick way to reduce warming.
The table gives information about three methods of reducing the amount of carbon dioxide in the atmosphere.
| Method | Information |
|---|---|
| planting new forests | cheap; trees absorb carbon dioxide by photosynthesis as they grow; needs very large areas of land; the carbon dioxide is released again if the trees are burned or cut down and left to rot |
| carbon capture and storage at power stations | captures about 90 % of the carbon dioxide from a power station; carbon dioxide is stored in rocks deep underground; expensive; uses extra energy; there is a risk of leaks |
| replacing coal power stations with wind farms | no carbon dioxide released when generating electricity; some carbon dioxide released when turbines are made; wind is not always available; turbines can be noisy and change the landscape |
Evaluate the three methods. In your answer, consider the scale of each method, the risks and the environmental implications.
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.