118 I PART 2 I SOCIAL AND ECONOMIC IMPACTS
SUMMARY I SOCIAL AND ECONOMIC IMPACTS The second part of this report deals with the socio-economic impacts of climate change on a few key sectors of the Vietnamese economy, mainly agriculture and energy, and on a few key dimensions of Vietnamese society, mainly health and labour quality.
Infectious disease and mortality, two climate sensitive aspects of health As Viet Nam develops, the mortality and morbidity due to infectious diseases is projected to drop from 33% and 38% in 1996 to 6% and 18% respectively in 2026. However, many infectious diseases remain endemic, including Tuberculosis, Chikugunya, Dengue, Rabies, Diarrhoea, and Respiratory Infections; there have also been episodes of Avian Flu. Infectious disease developments and mortality dynamics in Viet Nam may also be strongly affected by climate change. There is much evidence of significant positive association between temperature and infectious diseases, including increased cases of diarrhoea, enteric bacteria disease, and hand-mouth-foot diseases, for example. By using data of provincial monthly infections of 28 types of diseases in 2009–2018 from the Viet Nam Ministry of Health, we estimate the short-term effects of weather variation (temperature, rainfall, wind speed, heatwave) and long-term effects of climate on the incidence of multiple infectious diseases (i.e. water-borne, airborne, and vector-borne) in Viet Nam, taking the role of public health expenditures for adaptation into account. Temperature and windspeed affect three major types of infectious disease, including vector-borne, airborne, and water-borne, in all regions of Viet Nam, although at dissimilar levels. The strongest effect is found for vector-borne disease. The effects are heterogeneous across different climatic regions of Viet Nam and depend on the role of health-care expenditure. The cold region will have a higher incidence rate of diseases if the temperature rises. By contrast, the hot region will have a higher disease impact if the regional temperature falls. The potential indirect cost of infectious diseases caused by future global climate warming is evaluated through the induced labour productivity loss: a 1% increase in disease infections leads to a decrease in the average hourly wage of approximately 0.05%. This is the marginal cost on worker productivity of an incremental change of temperature. It is only a part of the economic cost of infectious diseases. Indeed other costs include the loss in wages and the cost of preventing and treating the diseases. Furthermore, social costs include reduction of life expectancy and quality of life due to disease-related disability. We also examine the effect of cold and heat waves on mortality in Viet Nam. We find robust evidence on the positive effects of heat waves on mortality. The effect of heat waves tends to increase when the heat wave lasts for a longer time, which is the case in all future climate change scenarios.
