1 – Wrong
The text makes an argument based on the fact that the world suddenly stopped burning fossil fuels. So statement 1 is irrelevant.
2 – Correct
The text’s assumption is that in fifty years’ time, the carbon dioxide levels would be double of what was present pre-industrial level. However, it fails to recognise that carbon dioxide levels can be decrease significantly in fifty years’ time.
3 – Wrong
Past predictions cannot be generalised with this prediction. So statement 3 is irrelevant.
Only statement 2 is correct. So B is the answer.