Climate Change and Health

Climate change is already jeopardizing health and well-being in the U.S. and abroad, and is projected to become a greater public health threat in the decades to come.

Hand holding a leaf

CLIMATE CHANGE is already jeopardizing health and well-being in the U.S. and abroad, and is projected to become a greater public health threat in the decades to come. The World Health Organization has outlined some of the key ways in which climate change affects health. As the examples in this issue demonstrate, Fielding School faculty, students and alumni are leading efforts to protect populations against this developing crisis.


  • Extreme temperatures contribute to deaths from cardiovascular and respiratory disease, particularly among the elderly.
  • Heat raises the levels of ozone and other pollutants in the air that exacerbate cardiovascular and respiratory disease.
  • Higher levels of  pollen and other allergens in the air, which are also associated with heat, can trigger asthma.


  • The number of weather-related natural disasters has more than tripled worldwide since the 1960s. These disasters result in more than 60,000 deaths per year, mainly in low-income countries.
  • Floods, which are increasing in frequency and intensity, contaminate freshwater supplies, heighten the risk of water-borne diseases and create breeding grounds for disease carrying insects such as mosquitoes.
  • Rising temperatures and variable precipitation are likely to decrease the production of staple foods in many of the world’s poorest regions — increasing the prevalence of malnutrition and undernutrition, which currently cause 3.1 million deaths per year.
  • More than half of the world’s population lives within 60 kilometers [37.28 miles] of the sea. Rising sea levels and increases in extreme weather events will destroy homes, medical facilities and other essential services. People may be forced to move, increasing the risk of a range of health effects, including poor mental health and communicable diseases.
  • Increasingly variable rainfall patterns are likely to affect the supply of fresh water. A lack of safe water can compromise hygiene and increase the risk of diarrheal disease, which kills more than 500,000 children under the age of 5 each year. In extreme cases, water scarcity leads to drought and famine. By the late 21st century, climate change is likely to increase the frequency and intensity of droughts.


  • Climatic conditions strongly affect  water-borne diseases and diseases transmitted through insects.
  • Changes in climate are likely to lengthen the transmission seasons of important vector-borne diseases, as well as altering their geographic range.
  • Malaria, which currently kills more than 400,000 people per year, is transmitted by Anopheles  mosquitoes and is strongly influenced by climate. The Aedes mosquito vector of dengue is also highly sensitive to climate conditions, and studies suggest that climate change is likely to continue to increase exposure to dengue, which is currently associated with approximately 25,000 deaths a year.

Source: World Health Organization 


Haroutune K. Armenian, MD, DrPH Professor in Residence, Epidemiology; Thomas R. Belin, PhD Professor, Biostatistics; Pamina Gorbach, DrPH Professor, Epidemiology; Moira Inkelas, PhD Associate Professor, Health Policy and Management; Marjorie Kagawa-Singer, PhD, MN Professor Emerita, Community Health Sciences; Cathy Lang, PhD Director for Research Administration; Adjunct Assistant Professor, Community Health Sciences; Michael Prelip, DPA Professor and Chair, Community Health Sciences; Beate Ritz, PhD Professor, Epidemiology and Environmental Health Sciences; May C. Wang, DrPH Professor, Community Health Sciences; Elizabeth Yzquierdo, EdD Assistant Dean for Student Affairs; Adjunct Assistant Professor, Community Health Sciences; Zuo-Feng Zhang, MD, PhD Associate Dean for Research; Professor, Epidemiology; Yifang Zhu, PhD Associate Dean for Academic Programs; Professor, Environmental Health Sciences; Frederick Zimmerman, PhD Professor, Health Policy and Management; Mark Alsay and Ivan Barragan Co-Presidents, Public Health Student Association; Rita Burke, MPH ’03, PhD ’08 President, Public Health Alumni Association  


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