Future urban land expansion and implications for global croplands

Abstract

Urban expansion often occurs on croplands. However, there is little scientific understanding of how global patterns of future urban expansion will affect the world's cultivated areas. Here, we combine spatially explicit projections of urban expansion with datasets on global croplands and crop yields. Our results show that urban expansion will result in a 1.8-2.4% loss of global croplands by 2030, with substantial regional disparities. About 80% of global cropland loss from urban expansion will take place in Asia and Africa. In both Asia and Africa, much of the cropland that will be lost is more than twice as productive as national averages. Asia will experience the highest absolute loss in cropland, whereas African countries will experience the highest percentage loss of cropland. Globally, the croplands that are likely to be lost were responsible for 3-4% of worldwide crop production in 2000. Urban expansion is expected to take place on cropland that is 1.77 times more productive than the global average. The loss of cropland is likely to be accompanied by other sustainability risks and threatens livelihoods, with diverging characteristics for different megaurban regions. Governance of urban area expansion thus emerges as a key area for securing livelihoods in the agrarian economies of the Global South.

Governance changes in peri-urban farmland protection following decentralisation: A comparison between Montpellier (France) and Rome (Italy)

“…Urbanisation is a global phenomenon with major implications for croplands worldwide (Bren d'Amour et al, 2016). Since the 1990s, a growing body of scientific literature has examined the urban conversion of farmland (Bryant and Johnston, 1992;Nelson, 1992) and its impacts on landscape, environment, and food security (Johnson, 2001;Plieninger et al, 2016).…”

Urbanization Effects on Vegetation and Surface Urban Heat Islands in China’s Yangtze River Basin

“…In addition, the increasing rate of global urban area is twice as fast as population growth [2]. Rapid urbanization can bring a series of problems, including urban heat island [3], reduction of cropland and vegetation coverage [4], changes of land surface phenology [5], and air pollution [6]. Thus, the magnitudes, the temporal trends and the relationships between the above-mentioned problems due to urbanization should be comprehensively investigated.…”

Sustainability in an urbanizing planet

“…Similarly, much evidence from local case studies indicates that urban expansion commonly results in the loss of agricultural land. The first global assessment of future agricultural land loss (5) shows that about 80% of the global cropland loss will take place in Asia and Africa, and that the loss will be acute in a few countries that could potentially lose up to one-third of total crop production. These observations suggest urban sustainability must be achieved at the global scale, raising a number of questions about scale: Are there fundamental urban characteristics that scale or converge with environmental outcomes and performance measures?…”