Anthropogenic appropriation of natural lands has long sustained human populations and activities. Human use of the environment has resulted in the degradation of green spaces and depletion of natural, particularly plant-based, resources. Human appropriation of net primary production (HANPP) is a globally available, spatially explicit measure of this human-driven extraction and diversion of plant biomass through harvesting (HANPPharv) and land use change (HANPPluc). Models for HANPP have been limited temporally (e.g., a year) or in terms of complexity (e.g., one predictor). In this study, I predict HANPPharv and HANPPluc from 1960 to 2010 at decadal intervals using Bayesian spatiotemporal models and demographic, economic, technological, and environmental variables. Models were then used to project HANPP to 2060 using the Shared Socioeconomic Pathways (SSPs) for future sustainability (SSP1) and regional rivalry (SSP3) scenarios. Models were robust and reliable, with predicted:observed R2 values of 0.99 and 0.98 for HANPPharv and HANPPluc, respectively. HANPPharv and HANPPluc were best predicted with population, gross domestic product (GDP), and anthropogenic greenhouse gas (GHG) emissions. Population was the primary predictor of both HANPP components. Using selected models, both HANPPharv and HANPPluc were projected to stabilize based on the SSP1 and continuously increase based on the SSP3. Results highlight the interconnections among humans, socioeconomic systems, and the environment. International collaboration to address environmental issues and the global displacement of environmental impacts, along with sustainable and efficient resource use and conservation of natural areas, will remain important for mitigating human-driven environmental impacts.
Michelle Bardales Cruz
Dr. David Jenkins, Advisor