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A number of anthropogenic perturbations are being applied to the climate system since pre-industrial times through changes in the atmospheric composition of the atmosphere, land use, and other changes. These perturbations are known as radiative forcings. The climate system responds to these perturbations through a series of changes called feedbacks in order to return to some equilibrium. A lot of research has focused on understanding and quantifying the feedbacks of the physical climate system; however the development of Earth System models has revealed the importance of biogeochemical feedbacks. The EUCAARI project has more specifically looked at climate feedbacks involving natural and anthropogenic aerosols.
The role of aerosols in climate and Earth system feedbacks was reviewed in EUCAARI. Available observational and model studies suggest that the regional radiative perturbations are potentially several Watts per square metre due to changes in natural aerosol emissions in a future climate. Taking into account only the direct radiative effect of changes in the atmospheric burden of natural aerosols, and neglecting potentially large effects on other parts of the Earth system, a global mean radiative perturbation approaching 1 W m-2 is possible by the end of the century. The level of scientific understanding of the climate drivers, interactions and impacts was assessed as very low.

EUCAARI has pushed our understanding further concerning biogenic SOA, marine DMS and dust, and has also studied the effect of climate change on sea spray particle emissions and their radiative effect. This was done through the use of three Earth System models including aerosols and their couplings to other components of the Earth System.