Abstract
Projections of future sea-level change are characterized by both
quantifiable uncertainty and by ambiguity. Both types of uncertainty are
relevant to users of sea-level projections, particularly those making
long-term investment and planning decisions with multigenerational
consequences. Communicating information about both types is thus a
central challenge faced by scientists who generate sea-level projections
to support decision-making. Diverse approaches to communicating
uncertainty in future sea-level projections have been taken over the
last several decades, but the literature evaluating these approaches is
limited and not systematic. Here, we review how the Intergovernmental
Panel on Climate Change (IPCC) has approached uncertainty in sealevel
projections in past assessment cycles and how this information has been
interpreted by national and subnational assessments, as well as
alternative approaches used by recent US subnational assessments. The
evidence reviewed here generally supports the explicit approach to
communicating both types of uncertainty adopted by the IPCC Sixth
Assessment Report (AR6).