Demographic changes will shape planetary biodiversity

Abstract

Recent studies have highlighted how future population growth in combination with other contemporaneous global drivers can degrade natural capital and the associated ecosystem services whereas policies that invest in nature can yield benefits for multiple economic and environmental variables. However, studies have yet to highlight and isolate the consequences of changing demographic dynamics in different world regions on global patterns of biodiversity. To fill this research gap, we link a computational general equilibrium economic model (GTAP-AEZ) with biodiversity characterization factors representing potential species loss per unit area due to human land-uses in different world regions for mammals, birds, amphibians, reptiles, and plants combined. This allows us to project the impact on species loss of a business-as-usual global economic scenario between 2021 and 2041, driven by changes in population, GDP, capital stock, labor force, and productivity growth. Second, we focus on demographic change as a sole driver of biodiversity loss and contrast the impacts of historical population growth (2001−2021) with those of future demographic trends (2021–2041) using the same biodiversity metric and economic model. Third, we analyze how the biodiversity projections are affected by the underlying uncertainty in 2041 population based on the United Nations Probabilistic Population Projections. Finally, we also identify those economic sectors and the three major market mechanisms driving the land-use change that explains biodiversity loss in each region. These are: domestic substitution of imports; direct increase in trade to satisfy the increased population abroad; and indirect increase in trade through third markets. The findings highlight how slowing population growth in the wealthiest countries will benefit biodiversity in some parts of the world, while continued strong population growth in Africa will lead to more rapid biodiversity loss in other regions. Our results provide insights into the global hotspots, drivers, and linkages that can be useful to diverse stakeholders (businesses, governments, and conservationists) for making progress towards the achievement of the global biodiversity targets and the UN Sustainable Development Goal 15 (Life on Land).