Review article: Past and future climate–related hazards in Indonesia

Abstract. Indonesia, one of the most populous countries, ranked fifth globally for climate-related hazards and disasters in the past five years. This study aims to assess historical trends, future projections, and potential implications of climate-related hazards in Indonesia. We synthesize literature, analyze historical datasets, and examine CMIP projections to assess the trend of extreme climate events and their potential effects on climate hazards. Results show that current records and studies predominantly highlight floods as the most common hazard in the tropical–humid region, followed by landslides, droughts, extreme weather, and wildfires. Historical evidence indicates an increasing threat of flood by intensifying amplitude and frequency of rainfall extremes by around 25 %, especially in most northern parts of Indonesia (Kalimantan, northern Sumatera, parts of Sulawesi, and Papua), while the drought amplified by 60 % over the country across the dry regions from southern Sumatera, Java to Nusa Tenggara. These trends are projected to persist under future climate scenarios (SSPs or RCPs). We found that urban factors like land subsidence and landuse change, particularly in cities like Jakarta, may worsen flood impacts in the future. Future studies should also examine rainfall-induced landslides and flash floods in other vulnerable areas, such as steep areas. Additionally, drought, often overlooked in this country, requires comprehensive research given its unique slow onset and its agricultural and societal effects. Global teleconnection mechanisms (ENSO, IOD, MJO) have intensified wet and dry hazards in recent decades and must be considered. A more integrated approach, combining cascading process models, impact assessments, early warning systems, and adaptive land-use practices, is essential to enhance resilience against climate hazards in Indonesia.