Worksheets on AQA GCSE Chemistry 9.2 Carbon dioxide and methane as greenhouse gases, covering 9.2.1 Greenhouse gases, 9.2.2 Human activities which contribute to an increase in greenhouse gases in the, 9.2.3 Global climate change, and 9.2.4 The carbon footprint and its reduction, with answers. Print them, or work through one on screen. Write your working straight onto the paper and Genie marks it question by question against the mark scheme.