Weather is the term used to describe theatmospheric conditions (heat, wetness, wind, etc.)prevailing at any one place and time. Climate is the sum ofthe prevailing weather conditions of a given place over aperiod of time, typically summed over many decades. Thispaper seeks to provide strategic directions formainstreaming support for climate change within the WorldBank's broader program of assistance to Vietnam. Itdoes so by reviewing the current understanding of climatechange in Vietnam and likely impacts, outlining principlesto guide the Bank's engagement in this field, andapplying these principles across a range of sectors, takinginto account both near- and longer-term considerations. Thereport identifies elements of the Bank's current andplanned portfolio of projects and analytical work that arecontributing or will contribute to improved knowledge,planning, and actions, and it points to additional areaswhere new or more work seems warranted. The reportrepresents a first iteration of a strategy for supportingVietnam in managing the challenges posed by climate change.As more experience is gathered and as our understanding ofboth the science and the economics of climate change impactsin Vietnam improves, this strategy will need to be revisitedand refined. While the process of climate change is expectedto be a long-term phenomenon-with predictions forconsiderable changes through the second half of thetwenty-first century, the focus of this report is ondecisions and priorities that should govern the Bank'sassistance during this decade. Given an array ofuncertainties, extending the developing assistance planningvision much beyond 2020 is not practical. This time framealso corresponds to the government of Vietnam's ownplanning horizon.