The new strategy, Nature and the National Trust, identifies the habitats and species in the trust's care that are most at risk and outlines how to ensure their survival in a changing environment.
The strategy was drawn up following the publication earlier this year of the trust's Shifting Shores report. This revealed that 60 per cent of the trust's coastal properties could be eroded within the next 100 years as a result of rising sea levels and more frequent storms.
David Bullock, head of nature conservation for the National Trust, said: "Nothing stays the same, and that has always been the case, but the rate of change is now enormous. Climate change means that we have to look carefully at what we mean by conservation. It's more about managing for change, rather than trying to preserve what we own."
Essentially, the trust - one of the UK's biggest charities with 3.4 million members - will be switching from a fragmented approach to managing its properties to managing them on a "landscape scale" - taking account of the surrounding area as well the areas it owns.
"There may be species inhabiting our properties that are not used to the more Mediterranean climate that is emerging, so they might move north," Bullock explained. "We need to work with partners in order to give them that room to move. Our new strategy is quite different from classic nature conservation objectives."
Shifting Shores predicts that 15 per cent of the trust's costal properties could be eroded by more than 100m over the next century, and says 126 of its sites are at risk of flooding.