Modelling the impacts of ozone pollution and climate change on future crop productivity

Development and application of crop models to simulate the effect of ozone pollution and climate change on future productivity of staple crops.

The project aims to improve understanding of where combined ozone and climate stress is projected to reduce crop yields the most. This could help policymakers identify which countries might gain most from considering ozone-precursor measures in their nationally determined contributions, with potential benefits for food security, climate, and public health.

Ground-level ozone is an air pollutant that can damage crops and reduce agricultural productivity. Its effects are influenced by climate conditions, including temperature, water availability, and atmospheric carbon dioxide concentrations. As climate change alters these conditions, understanding how ozone pollution interacts with other environmental stresses is increasingly important for assessing future food production.

Existing crop models can simulate some of these interactions, but they have largely been developed and applied using only single crop models and often  focusing on individual crops and specific regions. This increases uncertainty in productivity loss estimates limiting the contribution that the full extent of our knowledge could provide to global assessments.

This crop modeling approach also improves on traditional methods for estimating ozone-related crop losses, which relied on dose–response relationships that map plant damage directly to ozone concentration and cannot fully capture interactions between ozone and changing climate conditions like temperature, drought, and carbon dioxide, which modify ozone absorption.

By developing, evaluating, and applying an ensemble of crop models, this project will help address these knowledge gaps. Over the longer term, a clearer picture of combined stresses could inform crop breeding programs exploring ozone-tolerant varieties, and support adaptive practices that would guard against both ozone pollution and the adverse effects of climate change.

The findings will provide a stronger evidence base for understanding the potential benefits of ozone mitigation under different future climate scenarios, thereby informing international climate and clean-air assessments. The approach is also intended to give researchers a shared basis for future assessments of ozone mitigation’s multiple benefits.

Project activity

The project will bring together experimental evidence and crop modeling to investigate how ozone pollution and climate change affect the productivity of major staple crops.

The research will take place in two phases.

Phase I: Developing and evaluating crop models

The project will develop and evaluate an ensemble of approximately ten crop models that incorporate ozone-induced yield losses. Model performance will be assessed against experimental data collected across multiple sites in Europe and Asia, covering different years and wheat varieties.

Phase II: Assessing global impacts

A selected group of crop models will then be applied at the global scale to assess how future ozone pollution and climate change could affect crop yields according to projected emission pathways and associated changes in climate and ozone pollution. Wheat will be the main focus, with additional analysis of maize, rice and soybean.

The modelling will examine how heat, drought and the fertilization effects of elevated carbon dioxide influence yield losses associated with ozone pollution. This will help researchers distinguish ozone effects from other environmental stresses.

The project’s key outputs will include:

• Two planned scientific publications presenting the results of crop model development, evaluation and global impact assessment.
• A tested crop modeling methodology for assessing the combined effects of ozone pollution and climate-related stresses on crop growth and yield.
• Global assessments of crop yield impacts, identifying regions and countries where ozone pollution and climate change could pose substantial risks to agricultural productivity in the future.
• Evidence for climate and clean-air policy, helping identify where reducing ozone precursor and GHG  emissions could deliver benefits for food production, climate mitigation and public health.
• Research contributions to international assessments, including engagement to support the consideration of findings in the IPCC AR7 Working Group II physical impacts report.