Peatlands, in which a large share of the world's soil carbon is locked, are a living resource that takes centuries to form. Yet they can be drained and burned within a single dry season. Each year, millions of tonnes of carbon dioxide are released when peatlands are drained for agriculture. That is alarming, and not just for local farmers. Peat can trap huge quantities of carbon in the form of partially decomposed plant matter and prevent it from escaping into the atmosphere.

On the basis of the above passage, the following assumptions have been made:

1. Large-scale peatland drainage is a major reason for widespread food insecurity in the world.

2. Peatland drainage is mainly driven by urban expansion.

3. Conserving peatlands helps in combating climate change.

Which of the above assumptions is/are valid?