Human population is an important component and key element of the Earth system. However, current population-related analyses are mainly restricted to administrative units (e.g., country) only, let alone the border areas. Using over two-decade (2000-2020) WorldPop-based population data, here we conduct the first global-coverage, spatio-temporal analysis of the distributions, patterns and trends of population in the borderlands. We find that the global borderlands have undergone an obvious and accelerating process of population growth and agglomeration. Above 1/6 of total population were located in the (cross-)border areas of a 60-km buffer zones, while it also brought over 1/5 of global population growth over the past 21-years, larger than the United States’s totality. The growth rate of population per year in the borderlands has more than 8% above the global level since 2000, and yearly differences of both them increased from 0.2% to 0.8%. Overall, 176 out of the 313 borderlands (56%) of population agglomeration showed an ascending trend, among 46% of type was above-average population density area. The ratio of the border population in the growth and decline areas was from 6:4 in 2000-2010 to 7:3 in 2010-2020, particularly the moderate population growth areas increased from 43% to 53%. Also, over 70% of national borderlands was net increase areas, mainly distributed in developing countries like India, Brazil, and Nigeria. Our new insights can provide guidance and practice for exploring the mechanism, cause-effect and impact-response of border-prone characteristics of population growth, promoting the inter- and multi-disciplinary studies like border geography. We thus appeal more effective efforts from governments, scientific community, and international initiatives (e.g., the 2030 SDGs) to further study the issues of borderlands sustainable development.

WorldPop, Borderlands, Population growth and agglomeration, National differences, Border geography