Volatile organic compounds (VOCs) are reactive drivers of tropospheric chemistry, impacting the formation of secondary organic aerosols and of ozone. The composition and amount of their emissions are changing with climate change and with humanity’s switch to cleaner energy sources. Through airborne flux measurements, it is possible to map emissions and compare them with emission inventories, uncovering gaps in those inventories. Such measurements performed in California showed a dominant contribution of temperature-dependent VOC emissions, including non-traditional anthropogenic sources such as solvents, as well as biogenic VOCs, to air pollutant formation.

Future changes in biogenic VOC emissions are especially uncertain, because climate change induces increasing stress – such as drought, heat or herbivory – in plants. A plant climate chamber combined with the atmospheric oxidation chamber SAPHIR at Forschungszentrum Jülich enables the investigation of particle and ozone formation following the oxidation of real tree emissions under various stress conditions. First results show the complexity of climate stress impacts on BVOC emissions and chemistry.