Megacities destroy rainforests

“Global urbanization is tied to the destruction of rainforest in Brazil,” says Stephan Barthel, environmental researcher at the University of Gävle.

The cities in Asia and Africa are expanding on some of the most fertile agricultural lands on the planet and their rapid growth is on a scale which will affect our common ability to produce food in the future.

The cities need food

Researchers show that megacities need to compensate for themselves through a process of deforestation in completely different places, and they crave a surface three to four times as large, since such forestland is three to four times less productive.

“This phenomenon can be witnessed in, for example, Brazil. When we use forestland for agricultural purposes, we lose biological diversity and capacity to store coal, which in turn will increase climate change,” Stephan Barthel explains.

Urban farms are disappearing

Historically, cities themselves ensured that their city land was productive, with circular flows in which waste products were re-used, as cities depended on such processes. Stephan Barthel points out that functioning urban farms in the Global South still exist. However, like in the Global North, economic globalisation is intertwined with large-scale urbanisation, so urban farms are disappearing.

“As urban farms disappear, cities need to compensate for that loss for the purpose of food security. This explains why forests disappear, and it is often the tropical rainforests. Moreover, very powerful states, like China and India, are buying land in Africa, Eastern Europe and South America which speeds up this process.”

A problem we overlook

Urban farms exist in all cities, and first we need to recognise their importance and give them support. The next step is to use local legislation to protect them as if they were nature reserves. Urban farms must be acknowledged for their valuable contribution; they are protecting highly fertile land simply by using is and this is vital both from a local and global perspective.

“We suggest a strategy which is a combination of global politics for land use (which is to include a UN resolution similar to the one about biodiversity loss), regional planning and local governance. Such a strategy could act as support for local politicians, because the solutions are local and regional.

“The problem of land conversion is clearly overlooked. We tend to see only the benefits of urban expansion. The reason for this is that the short-term financial advantages are numerous: the increase in tax revenues, the building of new homes and the creation of new jobs. And the list goes on and on,” Stephan Barthel concludes.

Urban Studio

Related information:
Barthel, S., Isendahl, C., Vis, B. N., Drescher, A., Evans, D. L., & van Timmeren, A. (2019). Global urbanisering och livsmedelsproduktion i direkt konkurrens om mark: Utnyttja platser för att minska påverkan på SDG2 och på jordsystemet. Anthropocene Review

For more information, please contact:
Stephan Barthel, reader in geospatial information science and director of the Urban Studio, University of Gävle.
Phone: 076-360 57 05
E-mail: stephan.barthel@hig.se

Text: Douglas Öhrbom
Photo: Rainforest Roland Johansson/TT Nyhetsbyrån