What else could farmland be used for?

Mainly nature, forest and rewetted wetlands, or other crops. Farming and forestry cover 72 percent of Denmark's land, most of it growing feed for livestock1. In the Danish Climate Council's scenario for biodiversity and water quality, about 760,000 hectares of farmland are taken out for nature and forest by 20502. Taking carbon-rich lowland soils out of farming and rewetting them is expected to give more nature and cut nitrogen reaching coastal waters by about 40 kg per hectare a year3.

If the land simply grows other crops, the gain is smaller. An Aarhus University note calculated that 10 percent fewer livestock would cut greenhouse gases by 7 percent but leave nitrogen leaching almost unchanged, because it assumes the land grows other crops and manure is replaced by mineral fertiliser4. The note was not reviewed by outside researchers, and it does not count production moving abroad5. Globally, one study found that a shift to more plant-based diets by 2050 could free land where restored vegetation would absorb 332 to 547 billion tonnes of CO26.