The four sentences $( \text{labelled} \; 1, 2, 3, 4)$ below, when properly sequenced would yield a coherent paragraph. Decide on the proper sequencing of the order of the sentences and key in the sequence of the four numbers as your answer:
- A popular response is the exhortation to plant more trees.
- It seems all but certain that global warming will go well above two degrees – quite how high no one knows yet.
- Burning them releases it, which is why the scale of forest fires in the Amazon basin last year garnered headlines.
- This is because trees sequester carbon by absorbing carbon dioxide.