Climate change presents significant risk-management challenges to the New York metropolitan region. The potential for higher temperature, rising sea level, precipitation changes, and increases in droughts and floods affects decision-making in regard to coastal infrastructure, water supply and quality, health, and energy demand. A new suite of climate scenarios, based on global climate model (GCM) simulations carried out for the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report, has been developed for use by regional stakeholders. Model-based probabilistic scenarios are useful for capturing some of the uncertainties associated with climate change projections. Regional climate models (RCMs) as well as statistical techniques are used to down-scale GCM projections. Additional components of scenario development include analysis of severe storm risk (including hurricanes) and assessment of low probability, high impact events. Recent trends in temperature, precipitation and sea-level rise consistent with climate change projections are evident in the region. The use of scenarios enables the integration of science-based planning through consistent assumptions and methods related to climate change, with explicit characterization of uncertainty. Assessment of climate risks aids in development of improved responses to current as well as future extremes.