SHIVA (Stratospheric ozone: Halogen Impacts in a Varying Atmosphere), a further proposal for a Collaborative Project in the 2^nd call of the 7^th Framework Programme, aims to reduce uncertainties in present and future stratospheric halogen loading and ozone depletion resulting from climate feedbacks between emissions and transport of ozone depleting substances (ODS) from the surface into the stratosphere. Of particular relevance will be studies of short and very short-lived substances (VSLS) with climate-sensitive natural emissions. If funded SHIVA would provide valuable input to the SHARP consortium.