This chapter provides a brief description of Papua New Guinea, its past and present climate as well as projections for the future. The climate observation network and the availability of atmospheric and oceanic data records are outlined. The annual mean climate, seasonal cycles and the influences of large-scale climate features such as the West Pacific Monsoon and patterns of climate variability (e.g. the El Niño‑Southern Oscillation) are analysed and discussed. Observed trends and analysis of air temperature, rainfall, extreme events (including tropical cyclones), sea-surface temperature, ocean acidification, mean and extreme sea levels are presented. These projections are presented along with confidence levels based on expert judgement by Pacific Climate Change Science Program (PCCSP) scientists. The chapter concludes with a summary table of projections (Table 11.4). Important background information, including an explanation of methods and models, is provided in Chapter 1. For definitions of other terms refer to the Glossary. Projections for air and sea-surface temperature, rainfall, sea level, ocean acidification and extreme events for the 21st century are provided.
