Worldwide CO2 emissions in 1990 were 21.8 billion tonnes.
Worldwide CO2 emissions in 2010 were 33.1 billion tonnes.
Given that A A\,A billion tonnes represents the worldwide CO2 emissions n n\,n years after 1990.
Using a linear model, form an equation linking A A\,A with nnn.
Hence estimate worldwide CO2 emissions in 2030.
In 2016 worldwide CO2 emissions were 35.4 billion tonnes.
Comment on the suitability of your model in light of this information
260 exam-style questions on Edexcel A Level Maths Straight Line Graphs, covering 5.1 y = mx + c, 5.2 Equations of Straight Lines, 5.3 Parallel and Perpendicular Lines, 5.4 Length and Area, and 5.5 Modelling with Straight Lines. Each one has a worked solution and a mark scheme showing where the marks go.