Global urban expansion has been continuously accelerating since 2000, according to a recent research article published in the journal Science Bulletin.

The research, conducted by teams from the Institute of Geographic Sciences and Natural Resources Research of the Chinese Academy of Sciences, Northeast Agricultural University and Fujian Normal University, showed that the global urban land area expanded from 239,000 square km in 2000 to 519,800 square km in 2020.

Using big data obtained through satellites, the researchers developed 30-meter-resolution data products of global urban expansion, urban impervious surfaces, green spaces and water areas for every five years from 2000 to 2020.

In the 10 years from 2010 to 2020, global urban expansion moved at a speed of 17,500 square km per year -- faster than the decade prior.

Global urban green space totaled 171,600 square km in 2020, accounting for 33 percent of the total urban land area, up from 65,400 square km and 27 percent of total urban land area in 2000, according to the research. (Xinhua)