This report is a rigorously researched, peer-reviewed scientific assessment of the climate of the western Pacific region. Building on the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, it represents a comprehensive resource on the climate of the Pacific. 

Volume 1: Regional Overview  presents an overview of the region: analysis of large-scale climate phenomena such as the El Niño-Southern Oscillation, seasonal variability and past climate trends and further develops regional climate change projections. 

Volume 2: Country Reports presents individual country reports which provide country-specific projections and relevant climate information. Countries covered are Cook Islands, East Timor, Federated States of Micronesia, Fiji Islands, Kiribati, Marshall Islands, Nauru, Niue, Palau, Papua New Guinea, Samoa, Solomon Islands, Tonga, Tuvalu and Vanuatu.

This report was published in 2011 as a major output of the Pacific Climate Change Science Program (PCCSP), which preceded the PACCSAP Program. PCCSP was funded by the Australian Government and delivered by a partnership between the Australian Bureau of Meteorology and Commonwealth Scientific and Industrial Research Organisation (CSIRO) during the period 2009–2011.

This report is supplemented by the 2014 PACCSAP report Climate Variability, Extremes and Change in the Western Tropical Pacific: New Science and Updated Country Reports.