Executive Summary A sia and the Pacific host the greatest number of people vulnerable to the projected adverse impacts of climate change. Climate change is expected to modify and often to magnify the current burden of diseases in the region. With projected increases in temperature and changes in rainfall patterns (generally yielding drier climate in dry seasons and wetter climate in wet seasons), and an increase in the frequency and/or intensity of tropical cyclones and storms, climate change will significantly challenge the public health community at the global, national, and local levels. While all populations are vulnerable to climate-induced health risks, the most vulnerable remain those in low-income groups with little adaptive capacity, among which the elderly, children, and women are most vulnerable. Reducing vulnerabilities and increasing resilience to help people cope with health effects of climate change will increasingly become a priority for the region, while new innovative approaches should be explored to protect these populations. This study aims to improve the understanding of the human health dimensions of climate change and how projects in sectors other than health, such as agriculture, water financing, and disaster risk reduction need to account explicitly for the health impacts of their interventions. The Threat to Health Posed by Climate Change The Intergovernmental Panel on Climate Change (IPCC) concluded in 2007 that climate change and global warming is without doubt happening, and that in all likelihood (greater than 90% probability) this warming is primarily caused by human activity. Furthermore, recent observations show that some climate indicators are near or beyond the upper range of the IPCC’s 1990 projections. A warmer and unstable climate is expected to adversely affect health, with disproportionately larger impacts on the poor and vulnerable, mainly through four courses: (i) extreme weather events causing injuries and deaths, water contamination, infectious diseases, food shortages, and mental health problems; (ii) droughts and heavy rainfall causing significant reduction in crop yield and subsistence agriculture, which may lead to malnutrition, micronutrient deficiencies, or, in more extreme cases, starvation; (iii) an increase in the number of very hot days in large cities, along with forest fires and dust storms adversely impacting air quality over broad areas (both urban and rural) and exacerbating the occurrence and intensity of associated with high temperatures (e.g., heat strokes) and respiratory diseases (e.g., asthma attacks); and (iv) changes in temperature and rainfall patterns impacting not only the occurrence of vector-borne diseases such as malaria and dengue, but also changing and possibly extending the geographical habitat of the vectors of such diseases. East Asia, the Pacific, and South Asia are expected to bear a significant share of the impacts associated with these events. Indeed, historically, more people in Asia and the Pacific have been affected by floods, droughts, and storms than in any other region of the world: 83% of all people affected by droughts, 97% of all people affected by flood, and 92% of all people affected by storms over the period 1960–2007 resided in East Asia, the Pacific, and South Asia. The poor and the vulnerable are expected to experience the bulk of the projected impacts of climate change, including those impacts on health. A study by the World Bank recently estimated an average global cost of adaptation in the health sector for the prevention and treatment of diarrhea and malaria alone over the period 2010–2050 to reach $1.3 billion to $1.6 billion per year (in 2005 dollars) over the period 2010–2050 (above and beyond the prevention and treatment of these diseases in a scenario without climate change). East Asia, the Pacific, and South Asia are projected to account for approximately 50% of this estimated cost of adaptation (approximately vii