Environmental change in post-closure safety assessment for radioactive waste disposal is recognised as an issue in international recommendations, national regulatory requirements and safety assessment practice. The key drivers of environmental change are associated with climate change. The major implications for post-closure safety relate to consequent changes in hydrology and landscape, in turn having knock-on implications for model representation of the containment system and the biosphere, as well as radionuclide migration and accumulation within them. This paper presents work recently completed in working group 6 of the International Atomic Energy Agency’s MODARIA program, which focussed on “Development of a Common Framework for Addressing Climate Change in Post-Closure Radiological Assessment of Solid Waste Disposal”. The results include an overall methodology for taking climate change and landscape development into account in post-closure radiological impact assessments. It is intended to be applicable to a wide range of disposal facility types and provide a common, scientifically supported, basis for addressing these complex issues in assessments. The methodology is illustrated by a range of examples from on-going work at the national or project specific level, that indicate how the common approach can be applied to address locally relevant assessment specific contextual factors. Continuing activities in carrying the results forward are also briefly presented. These include the update of the reference biospheres methodology within the international BIOPROTA program and the trial application of the approach to further sites and facilities. The implications for long-term assessment of sites under long-term rehabilitation are also discussed