The densely populated cities of large mega-deltas on the Asian coastline face high exposure to sea-level rise, storm surges and river flooding. As coastal cities expand through accelerating urbanization, many of the most vulnerable people settle in hazard-prone areas on the margins of cities, and become increasingly exposed to disasters. Climate change threatens urban and rural livelihoods and settlements through increased river and sea flooding, which damages infrastructure, and saltwater intrusion into low-lying cropland causing considerable damage to crops. In addition to food and water security, floods and droughts constitute health risks as illness and death from waterborne diseases, heat stress and malnutrition due to droughts are expected to rise in East, South and South-East Asia.
In Australia and New Zealand, climate change is expected to reduce agricultural productivity and lead to a decline in species diversity. Warmer water temperatures and rising acidity increasingly lead to the loss of biodiversity of maritime ecosystems and the benefits they provide as sustainable livelihood sources (fisheries and tourism) and natural barriers against storm formation. Pacific small island states face inundation of low-lying territories due to sea-level rise and fresh water scarcity due to reduction in rainfall, inevitably leading to the need for resettlement.
Asia and the Pacific is already the world's most natural disaster-prone area, and climate change is anticipated to accelerate the frequency and intensity of such weather-related extreme events. According to the Internal Displacement Monitoring Center (IDMC), China, India and the Philippines accounted for the majority of the people displaced by disasters worldwide between 2008 and 2014.