This report provides a first-ever compilation of what is known—and not known—about climate change effects on freshwater aquatic and riparian ecosystems in the geographic extent of the North Pacific Landscape Conservation Cooperative (NPLCC). The U.S. Fish and Wildlife Service funded this report to help inform members of the newly established NPLCC as they assess priorities and begin operations. Production of this report was guided by University of Washington’s Climate Impacts Group and information was drawn from more than 250 documents and more than 100 interviews. Information in this report focuses on the NPLCC region, which extends from Kenai Peninsula in southcentral Alaska to Bodega Bay in northwestern California, west of the Cascade Mountain Range and Coast Mountains. The extent of the NPLCC reaches inland up to 150 miles (~240 km) and thus only includes the lower extent of most large watersheds. This area is home to iconic salmon, productive river, lake, and wetland systems, and a wide variety of fish, wildlife, amphibians, and other organisms. Many of these species, habitats, and ecosystems are already experiencing the effects of a changing climate.