A new feedback mechanism linking forests, aerosols, and climate

[摘要] The possible connections between the carbon balance ofecosystems and aerosol-cloud-climate interactions play a significant role inclimate change studies. Carbon dioxide is a greenhouse gas, whereas the neteffect of atmospheric aerosols is to cool the climate. Here, we investigated theconnection between forest-atmosphere carbon exchange and aerosol dynamics in thecontinental boundary layer by means of multiannual data sets of particleformation and growth rates, of CO₂ fluxes, and of monoterpeneconcentrations in a Scots pine forest in southern Finland. We suggest a new,interesting link and a potentially important feedback among forest ecosystemfunctioning, aerosols, and climate: Considering that globally increasingtemperatures and CO₂ fertilization are likely to lead to increasedphotosynthesis and forest growth, an increase in forest biomass would increaseemissions of non-methane biogenic volatile organic compounds and thereby enhanceorganic aerosol production. This feedback mechanism couples the climate effectof CO₂ with that of aerosols in a novel way.

[学科分类] 大气科学