The European JRC (Joint Research Centre) has launched a new tool with data on all 10,000 urban centers scattered across the globe. It is the largest and most comprehensive database on cities ever published. With data derived from the JRC’s Global Human Settlement Layer (GHSL), researchers have discovered that the world has become even more urbanized than previously thought.
Populations in urban areas doubled in Africa and grew by 1.1 billion in Asia between 1990 and 2015.
Globally, more than 400 cities have a population between 1 and 5 million. More than 40 cities have 5 to 10 million people, and there are 32 megacities with more than 10 million inhabitants.
Cities became 25% greener between 2000 and 2015. And although air pollution in urban centers was increasing from 1990, between 2000 and 2015 the trend was reversed.
With every high density area of at least 50,000 inhabitants covered, the city centers database shows growth in population and built-up areas over the past 40 years. Environmental factors tracked include:
Greenness: the estimated amount of healthy vegetation in the city center
Soil sealing: the covering of the soil surface with materials such as concrete and stone, as a result of new buildings, roads and other public and private spaces
Air pollution: the level of polluting particles such as PM2.5 in the air
Vicinity to protected areas: the percentage of natural protected space within 30 km distance from the city center’s border
Disaster risk-related exposure of population and buildings in low lying areas and on steep slopes
The data is free to access and open to everyone. It applies big data analytics and a global, people-based definition of cities, providing support to monitor global urbanization and the 2030 Sustainable Development Agenda.
The information gained from the GHSL is used to map out population density and settlement maps. Satellite, census and local geographic information are used to create the maps.