LONDON (Thomson Reuters Foundation) - Demand for new land to grow crops could lead to the conversion of natural areas close to the size of Brazil by 2050, potentially exceeding the level beyond which there is a risk of irreversible and abrupt environmental change, a U.N. report said on Friday.
The need to feed the planet's fast-growing population led cropland to expand 11 percent between 1961 and 2007, at the expense of savannah, grassland and forests, the report from the United Nations Environment Programme (UNEP) said. Environmental degradation and loss of biodiversity now affect an estimated 23 percent of the world’s soils.
"Recognising that land is a finite resource, we need to become more efficient in the ways we produce, supply and consume," UNEP Executive Director Achim Steiner said in a statement. "We must be able to define and adhere to the boundaries within which the world can safely operate to save millions of hectares by 2050.”
A shift to more protein-rich diets in developing countries and growing demand for biofuels and other bio-materials, especially in developed countries, are increasing demand for land, the report said.
"As demand grows, the price for land and derived products will increase, with potentially negative consequences for food security," the report warned.
The global cropland area could safely rise to 1,640 million hectares from around 1,500 million now. But by 2050, under business-as-usual conditions, expected land demand will overshoot safe limits, and an additional 320 million to 849 million hectares of natural land may be converted to grow crops, the report calculated, well above the 164 million considered safe.
The expansion of urban areas is also a problem, with up to 5 percent of global land (around 15 billion hectares) expected to be covered by built-up areas by 2050, it said. These often expand at the expense of agricultural land, and agricultural land expands at the expense of forests, especially in tropical regions, it noted.
SOS: HOW MUCH LAND IS SAFE TO USE?
The report, launched at the World Economic Forum in Davos, was produced by the International Resource Panel, a consortium of 27 resource scientists, 33 national governments and other groups hosted by UNEP.
The study tracks land use for domestic consumption in countries and regions, indicating whether they have gone beyond a "safe operating space" (SOS). This denotes the tipping point at which the risk of irreversible damage – through loss of biodiversity and fertile soils, release of carbon dioxide, and the disruption of water and nutrient cycles – becomes unacceptable.
For example, in the European Union, 0.31 hectares per person were needed in 2007 - a quarter more than what is domestically available in the region, and one third more than the globally available cropland per person.
“It's clear that developed nations are taking more than our fair share of the world's available land," said Michael Warhurst, a resource use campaigner with Friends of the Earth. "To cut Europe’s land use by a third, as the report says is necessary. We need to reduce our consumption of meat and dairy products and not use more land for biofuels or biomass."
In a foreword to the report, UNEP's Steiner said growth in cropland cannot be controlled by increasing yields alone, which have started to stagnate in some regions. He pointed to "new opportunities to steer consumption towards levels of sustainability, particularly in high-consuming regions".
Between 161 million and 319 million hectares of land could be saved by 2050, the report said, if the world followed measures including:
- planning land use to minimise expansion of built-up areas on fertile soils
- investing in the restoration of degraded land
- improving farming practices to boost yields in an ecologically and socially acceptable way
- cutting food waste and shifting towards more vegetable-based diets
- reducing subsidies for biofuel crops and phasing out biofuel quotas in consuming countries