Sites of special scientific interest (SSSIs) cover just under 7% of England, around 12 % of Wales and around 13 % of Scotland. In recent years, investments have been made to bring the habitats and species that SSSIs were designated for into ‘favourable’ condition. However, some SSSIs and other protected areas (PAs) are under direct physical threat from inundation following sea level rise, and changes in climate will affect the species and habitats that are present on most PAs. This report summarises these threats and considers options for changing the way that the protected area network is managed. The following impacts of climate change have already been detected on PAs; Saltmarshes have been lost to coastal squeeze, and coastal freshwater habitats including grazing marsh and lowland raised bog are at risk of inundation by seawater under current conditions Northern species have decreased in density, whilst southern species have increased in density. Whilst most evidence for this occurring on PAs comes from outside the UK, there is evidence that these patterns are occurring within the UK as well Southern species in the UK have used PAs to facilitate their northwards expansion In addition, the following impacts of climate change have been predicted to occur in future; The composition of flora and fauna on each PA will change – high confidence (medium evidence, high agreement) Cold adapted species of high latitudes and altitudes will tend to decrease on PAs, whilst warm adapted species will tend to increase – medium confidence (medium evidence, medium agreement ) PAs in the North of the UK will gain plant species overall, whilst PAs in the south are likely to lose plant species. This pattern is reversed for UK breeding birds – low confidence (medium evidence, low agreement) Species with lower dispersal capacities and those for which urban areas are a barrier to dispersal will be unable to colonize PAs that become climatically suitable – low confidence (limited evidence, medium agreement) Work in Africa predicted that some Important Bird Areas (IBAs) may lose all the species for which they were designated by 2085, although for around 90 % of species at least one currently occupied IBA should remain suitable. In Europe, species turnover is predicted to be faster than in Africa – medium confidence (medium evidence, medium agreement) Increasing range mismatching of interacting species, such as butterflies and their host plants, might mean that more management is necessary on PAs to preserve species that interact with each other – low confidence (limited evidence, medium agreement) Hotspots of bird diversity in Finland and Norway may no longer coincide geographically with PA boundaries – low confidence (limited evidence, medium agreement) Integrating consideration of climate change into management plans for the PA network is likely to result in more effective (and cost-effective) conservation solutions. In order to facilitate this integration, monitoring of climate change impacts and management actions should be carried out to enable adaptive decision making