Changes in Wood Biomass and Crop Yields in Response to Projected CO₂, O₃, Nitrogen Deposition, and Climate

As the world's population increases, so will the demand for food and timber resources. Though carbon dioxide (CO₂) fertilization and, to a lesser extent, nitrogen (N) deposition are expected to increase future resource production, changes in ozone (O₃) and climate have the potential to decrease production due to increased phytotoxic damage, drought, and heat stress. To determine how crop and timber production may change in the future, we use the Community Land Model version 4.5 with prognostic crops to simulate responses of wood biomass and crop yields to CO₂, O₃, N deposition, and climate under Representative Concentration Pathway 8.5 forcings. Generally, rising CO₂ increases wood biomass and crop yields, while projected climate change causes decreases. Small projected changes in O₃ and N deposition do not strongly affect yields, though additional research is needed on future O₃ and N deposition trends and impacts. By the end of the 21st century, global wood biomass increases by ~16% due to the dominating impact of CO₂. The positive effect of CO₂ on future crop yields is muted by the negative impacts of climate, with a ~5% net global increase. Future projections suggest that rice and wheat yields typically increase under the combination of future forcings, whereas soy and corn yields are regionally variable. While short-term resource management strategies can benefit from planting heat-tolerant species and cultivars, technological advances and intensification, among other management strategies not included here, must be employed to meet the future demand for these resources.