Climate change has become increasingly relevant and worrisome worldwide. There is a growing awareness that nature, conceived as an ensemble of natural ecosystems and their services, can make the environment more resilient. According to the scientific literature and documents released by national and supranational bodies, green infrastructures are key actions towards mitigation and adaptation to climate change. ‘Inner areas’ are defined as zones significantly far away from the main cities that supply essential services (education, health, and mobility), but are rich in important environmental and cultural resources. In these domains, the effects of climate change can contribute to depopulation. In Italy, inner areas broadly characterize southern Italian and insular regions: they host half of the Italian municipalities and roughly a quarter of the resident population. Inner areas comprehend ‘marginal areas’ that are defined as rural contexts showing a reduction of surface area used for agriculture, number of farms, and population. Sardinia shows mostly marginal areas and a significantly low climate resilience. In this paper, we aim at tailoring a green infrastructure-based strategy to achieve a higher climate resilience of marginal areas in Sardinia. Overall, our methodological approach includes three steps: literature review, definition of a case study, and proposal of guidelines aimed at adopting green infrastructures in built-up rural landscapes. Typically, in this paper, we focus on the first step of the method, by distilling from the scientific and grey literature the key elements of the guidelines including operational definitions of green infrastructures, practical examples, stakeholders’ involvement, and consistency check.