Population boom in the borderlands globally

Human population is an important component and key element of the Earth system, including eco-environmental issues. However, current population-related analyses are mainly restricted to administrative units (e.g., countries) only, and not the border areas. Using more than two-decades (2000-2020) of 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. Global borderlands have undergone an obvious and accelerating process of population growth and agglomeration. Above 1/6 of Earth's total population was located in the (cross-)border areas of a 60-km buffer zone, where over 1/5 of global population growth occurred over the past 21-years. The growth rate of population per year in the borderlands was greater than 8% above the global average. Overall, 176 out of the 313 borderlands (56%) showed an increasing trend of population agglomeration. The ratios of border population in growth and decline areas changed from 6:4 in 2000-2010 to 7:3 in 2010-2020. More than 70% of borderlands had net population increases, mainly distributed in developing countries like India, Brazil, and Nigeria. Our new insights can provide guidance and practice for exploring the mechanisms, cause-effects and impact-responses of border-prone characteristics of population growth, promoting inter-and multi-disciplinary studies such as border geography and environmental sciences. We thus appeal for international initiatives and more effective efforts from governments and the scientific community (e.g., the 2030 Sustainable Development Goals) to further study the issues of sustainable development in borderlands.

Automated summary

The population in borderlands has experienced significant growth and agglomeration, with over 1/6 of the global population located in these areas. The growth rate of population in these areas is higher than the global average. More than 70% of borderlands show population increases, mainly in developing countries. This study provides new insights into population growth in borderlands and calls for further research on sustainable development in these areas.