City and countryside
Every day in Germany more than 70 hectares of land are built over; globally the total is 2,880 hectares a day.
In 2007 for the first time in history more people lived in cities than in rural areas. In 2014, city-dwellers made up 54 per cent of the world population. By 2050 it will have increased to two-thirds.
Although there is a global trend towards urbanisation, there are still significant regional differences. In affluent countries up to 90 per cent of the population already lives in cities, but other regions are rapidly catching up: Latin America and the Caribbean are already highly urbanised (78 per cent), while Africa (38 per cent) and Asia (45 per cent) are still largely rural.
As cities grow, they bring myriad challenges for humans and the environment. Once fertile land is covered with structures or concrete, it is rarely ever returned to its previous state. Worldwide two hectares of land are lost to urbanisation every minute. With the land, many vital services performed by the soil are lost forever. Although Germany’s population is decreasing, every day some 70 hectares are developed for apartments, streets, and other infrastructure.
Soil that is covered with concrete is sealed and cannot absorb water any more. When large areas have been developed, heavy rain can easily lead to flooding. Soil also helps to regulate the local climate in cities. It has a cooling effect that helps to mitigate the urban “heat islands”. This function is becoming even more important due to climate change and the increase in extreme weather such as heat waves.
In many European cities there are already more than enough buildings to meet the needs of the population. By altering the ways we use existing structures and improving our transportation patterns, we can help to reduce the amount of fertile soil being sealed. The first steps towards this goal have already been taken. For example, today some rooftops are being used as to produce energy or food, to improve water absorption, or as a space for relaxation or sports activities.
Photo credit: CC Not A Cornfield@Flickr.com