Introduction I n early 2007, the Intergovernmental Panel on Climate Change (IPCC) released its Fourth Assessment Report, in which it noted that over the past 150 years, global average surface temperature has increased by 0.76 ºC, and that most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic (human) greenhouse gas concentrations. 1 It is generally believed that this global warming has caused changes in precipitation patterns, increased the frequency and/or intensity of extreme weather events, and has caused a rise in mean global sea levels. Looking into the future, the IPCC (2007) concluded: • • • • • • Even if greenhouse gas concentrations were to be stabilized at existing levels, anthropogenic warming and sea-level rise will continue for centuries to come, due to the timescales associated with climate processes and feedback effects; Both past and future anthropogenic carbon dioxide emissions will continue to contribute to warming and sea-level rise for more than a millennium; World temperatures may rise by between 1.1°C and 6.4°C during the 21st century, depending on which emissions scenario is realized (“best estimates” range between 1.8°C and 4°C); Sea levels will rise by 18 centimeters (cm) to 59 cm by 2100 mostly as a result of thermal expansion of the oceans, and only partly as a result of a global reduction in snow cover; There is a greater than 90% confidence level that there will be more frequent warm spells, heat waves, and heavy rainfall; and There is a greater than 66% confidence level that there will be an increase in droughts, tropical cyclones, extreme high tides, and storm surges. Asia and the Pacific host the greatest number of people at risk of adverse impacts of climate change. Historically, more people in Asia and 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 (Laplante 2010). With projected increases in temperature, changes in rainfall patterns, and increase in the frequency and/or intensity of tropical cyclones and storms, climate change is expected to impact almost every sector of human and economic activity, every region of the world, and every community, including the public health community.2 Although climate change is the biggest global health threat of the 21st century (Chan 2009), the status of knowledge on the relationship between climate change and health, and how the nature of this relationship may change with the socioeconomic characteristics of any given country, is mostly anecdotal, and remains insufficient to guide policy making. Furthermore, the failure to fully and explicitly account for the health impacts of investment projects, including adaptation investment projects, may exacerbate the health impacts of climate change, lead to under-investment in climate change adaptation, or elicit the wrong ranking and selection of adaptation options. Unless developing member countries (DMCs) of the Asian Development Bank (ADB) systematically anticipate, plan, and prepare adequate and cost-effective responses to the health effects of climate change, the 1 IPCC (2007). In the language of the IPCC, “very likely” stands for “with a probability greater than 90%.” 2 Thousands more have cases of suspected malaria. Furthermore, more than 200 health facilities have been damaged or destroyed, greatly reducing the available health care for millions of survivors. 1