Reading: Multiple Choice: Question 2

Peatlands form over thousands of years as partially decomposed plant matter accumulates in permanently waterlogged ground, too wet and too short of oxygen for normal decay to break it down. Across much of Europe, and in parts of Southeast Asia and North America, huge areas of peatland have been drained since at least the eighteenth century to convert the land for farming, forestry or fuel extraction, leaving the exposed peat to dry out for the first time in millennia.

The scale of what is lost in this process is easy to underestimate. Peatlands cover only around three percent of the planet's land surface, yet they store, in total, roughly twice as much carbon as all the world's forests combined, having locked it away in waterlogged, low-oxygen soil for thousands of years. Once a peatland is drained, the exposed peat is suddenly exposed to oxygen, and carbon that decay had never previously been able to touch begins to oxidise, releasing it into the atmosphere as carbon dioxide. Despite covering a tiny fraction of the land surface, drained peatlands are estimated to account for a disproportionately large share of global land-use emissions.

Restoring a drained peatland is, in principle, straightforward: engineers block the artificial drainage ditches with small dams to raise the water table back toward the surface, and conservationists reintroduce sphagnum moss, the plant primarily responsible for building peat in the first place. In practice, ecologists monitoring restored sites have found the transition is not immediate. Rewetting previously dried peat can trigger a temporary rise in methane emissions, a by-product of the anaerobic decomposition that resumes once oxygen is excluded again, meaning a freshly restored site can act as a net emitter of greenhouse gases for several years before it finally turns back into a net carbon sink.

This slow payoff complicates the politics of restoration. Farmers who have drained peat soils to grow high-value crops such as vegetables or flowers are often reluctant to give up productive land for a benefit that will not show up in the carbon accounts for years. Emerging carbon-credit markets, which pay landowners for verified long-term storage, are increasingly used to offset that reluctance financially.

Choose the correct letter, A, B, C or D.

1. How do peatlands compare with the world's forests in terms of carbon storage, according to the passage? A. They store roughly half as much carbon as all forests combined. B. They store slightly less carbon overall despite covering a larger area. C. They store a similar amount of carbon, but only in tropical regions. D. They store, in total, roughly twice as much carbon as all the world's forests combined.

2. What happens to peat when a peatland is drained, according to the passage? A. It develops higher water content and continues to accumulate carbon. B. It becomes exposed to oxygen and its stored carbon is released as carbon dioxide. C. It converts entirely into methane within a few months. D. It is largely unaffected because peat does not store carbon.

3. According to the passage, how is a drained peatland typically restored? A. By planting fast-growing trees to stabilise the exposed soil. B. By removing all remaining vegetation before applying fertiliser. C. By blocking drainage ditches to raise the water table and reintroducing sphagnum moss. D. By covering the surface with an impermeable membrane.

4. What did ecologists find about the period immediately after a peatland is rewetted? A. It can act as a net emitter of greenhouse gases for several years because of a rise in methane. B. It becomes a net carbon sink within a few weeks of rewetting. C. Carbon dioxide emissions rise sharply while methane emissions fall. D. All greenhouse gas emissions stop immediately once ditches are blocked.

5. Why are some farmers reluctant to support peatland restoration, according to the passage? A. Restoration requires them to pay a carbon tax immediately. B. Restoration is banned across most farming regions by law. C. Restored peatlands are said to attract pests that damage nearby farmland. D. They rely on the drained soil for growing high-value crops.