How does land use impact on global air quality and climate: a combined satellite and model study

Background and Motivation

Future pressures driven by food security and population growth result in anthropogenic land use change. Land use change impacts air quality by changing natural emissions both of gaseous and aerosol species, and impacts climate through radiative forcing. This occurs because land-use change alters atmosphere-biosphere interactions that influence radiation, moisture and carbon budgets. Vegetation also emits biogenic volatile organic compounds (BVOCs) that form secondary organic aerosols (SOA) that modify levels of major air pollutants particulate matter (PM2.5) and ozone and influence the abundance short-lived climate forcers (SLCFs). In addition, land use change is often brought about by fires and biomass burning that too cause poor air quality and impact climate. Understanding how current and future land-use change, such as large-scale deforestation, impacts atmospheric composition and radiation is important for global efforts to tackle poor air quality and mitigate climate change. A key uncertainty is our limited understanding of how land-use change influences air quality and climate through changes in BVOC emissions and SOA formation -this will be addressed in this project.

Aim and Objectives

This project will use satellite measurements combined with new and existing multi-model simulations to quantify the key processes and impacts of land use change on air quality and on climate. Our objectives are: to study emissions and atmospheric composition over major areas of deforestation; to assess multi-model simulations of land-use change impacts on air quality and improvements in model simulations with more detailed process representation; and to quantify how the combination of future changes in land use, climate and anthropogenic emissions will further impact air quality and climate.