Global Warming And Our
Health: Addressing the most
serious health impacts of climate
“If you look at climate Science has shown that global warming will affect human health across
change over the long the world. From diminished air quality and degradation of food and water
term, it will profoundly supplies to increasing levels of allergens and catastrophic weather events, we
affect the pillars of will experience a number of worsening health threats during our lifetimes.
public health: water, Fortunately, urgent action can help us avoid the worst of these impacts.
sanitation, air quality First, Congress must address global warming through mandatory legislation
and sufficient food.” 1 that reduces global warming pollution on the order of 80 percent by 2050.
Dr. DaviD Heymann, assistant In addition, the national and local public health system must protect
Director-General for HealtH communities by preparing for eight of the most pressing health hazards
security anD environment, associated with climate change.
WorlD HealtH orGanization
1. Extreme Storms Will Affect Health and heatstroke, cardiovascular disease, and kidney
Infrastructure: Science tells us that global disease. Extreme heat waves cause the most
warming has contributed to more hurricanes and harm among elderly and young children. City
intense storms in the North Atlantic during the last dwellers are at particular risk because of elevated
several decades. Increased storm wind speeds and temperatures in cities, known as the “urban heat
For more information, more intense rainfall are projected as the climate island effect.”
please contact warms.2 More severe storms and floods can lead
Kim Knowlton at
(212) 727-4579. to drownings, injuries, and outbreaks of infectious 3. Air Pollution Will Contribute to More
disease. Storms also damage basic infrastructure, Smog and Respiratory Illness: More than
with moisture leading to mold growth that can 100 million Americans currently live in counties
exacerbate allergies and respiratory illnesses. with ozone levels above national EPA standards.
Rising temperatures will increase ozone smog in
2. Heat Waves Will Lead to Increased Death many areas, especially in cities. Increasing levels
and Illness: The frequency and duration of heat of ground-level ozone are associated with increased
waves in the United States is projected to increase hospital admissions for people with respiratory
substantially because of global warming.3 As diseases such as asthma and will worsen the
temperatures increase, so do the number of deaths health of people suffering from cardiac or
www.nrdc.org/policy and illnesses occurring from heat exhaustion or pulmonary disease.4
Global Warming And Our Health:
Addressing the most serious health
impacts of climate change
4. Pollen Allergens Will Proliferate: 7. Water and Food Supplies Will Be
Higher temperatures and increased levels of Threatened: Global warming is expected to
carbon dioxide may cause allergenic pollen season worsen floods and droughts, threatening the
to start earlier, last longer, and be more intense.5 availability of water for drinking and irrigation.
For example, higher levels of carbon dioxide can Droughts diminish food variety, nutritional
cause ragweed to produce content, and availability—all of which can
60 percent more pollen contribute to malnutrition, infectious diseases,
Effects On: Adverse Health Impacts:
than normal. With and starvation. Warming ocean temperatures bring
Floods, storms Deaths, injuries, infectious disease outbreaks,
increases in airborne shifts in the geographic range of fish populations
mental health impacts on affected communities
Heat waves Deaths, hospitalizations, emergency department pollen, those who suffer and can severely impact local food supplies. One
visits, and heat-related illnesses from seasonal allergies are analysis predicts that by the year 2060, there will
Air pollution Increased concentrations of ground-level ozone likely to experience worse be an additional 40 to 300 million people at risk of
smog and fine particulate matter, increasing symptoms, including malnutrition from human-caused climate change.8
premature mortality and hospitalizations
hayfever and asthma. And global warming’s higher temperatures can
Airborne allergen Increased allergic illnesses (hay fever, asthma)
production due to longer pollen season and increases in the increase the risk of food-borne illnesses.
amount of pollen produced 5. Mosquito- and
Insect-borne Infections carried by mosquitos, ticks, and Tick-Borne Infectious 8. There Will Be Large Numbers of
infections other insects can spread into new areas Diseases Will Spread Environmental Refugees: Sea-level rise will leave
Water-borne Risk of cholera could be increased as coastal
More Widely: Climate some areas uninhabitable, forcing people to flee
infections and estuarine waters warm; extreme rainfall
events are associated with increased risks of change will affect the their homes in coastal regions. The United Nations
Cryptosporidium outbreaks patterns of diseases such estimates that in the next 10 years there will be up
Water and food More frequent drought, reduced drinking water as malaria, West Nile to 50 million “environmental refugees”—people
supplies supplies and crop yields, increasing world food virus, dengue fever, forced to migrate from their homes by a range of
insecurity; declining fisheries can contribute to
and Lyme disease.6 climate change-related environmental disasters
protein shortages; increased risks of food-borne
illnesses Warming temperatures like floods, droughts, and desertification.9 Health
Sea-level rise Contamination of coastal soils and drinking and increasing amounts among these refugees will be threatened by
water supplies; increasing storm surges and of rainfall have been associated increases in urban crowding, lack of
floods; large numbers of displaced people associated with increases water, and transmission of infectious diseases.
Table adapted from McMichael et al. (2006) in the occurrence and
transmission of insect-borne diseases, and higher Protecting Ourselves from the Worst
Walsh B. 2008. Can climate change make us sicker? TIME temperatures lead to more rapid development Impacts of Global Warming
Magazine (April 4, 2008).
IPCC. 2007. Climate Change 2007: The Physical Science Basis.
of dangerous pathogens within insect carriers. The range of potential threats to health and
Contribution of Working Group I to the Fourth Assessment Warming temperatures allow these diseases to life posed by global warming has never been
Report of the Intergovernmental Panel on Climate Change
[Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt expand their range into new, once cooler, regions. clearer. NRDC encourages national, state,
KB, Tignor M, Miller HL (eds.)]. Cambridge University Press,
Cambridge, United Kingdom and New York, NY, USA.
and local officials and other policymakers to
Confalonieri U, Menne B, Akhtar R, Ebi KL, Hauengue
3 4,5,6 6. Drinking Water Will Become Increasingly act immediately to reduce global warming
M, Kovats RS, Revich B, Woodward A. 2007. Human health
(Chapter 8). Climate Change 2007: Impacts, Adaptation and
Contaminated: Outbreaks of water-borne emissions at least 80 percent by 2050 in order
Vulnerability. Contribution of Working Group II to the Fourth diarrheal diseases caused by parasites, like Giardia to avoid the worst potential impacts of a changing
Assessment Report of the Intergovernmental Panel on Climate
Change, Parry ML, Canziani OF, Palutikof JP, van der Linden PJ, and Cryptosporidium, have been associated with climate. We must also prepare the public health
Hanson CE, Eds. Cambridge University Press, Cambridge, UK.
heavy rainfall events, which are likely to become system to respond to the range of anticipated
McMichael AJ, Woodruff RE, Hales S. 2006. Climate change
and human health: present and future risks. The Lancet more frequent due to global warming. For health threats that will accompany global
example, recent cholera outbreaks in Bangladesh warming. For more information, see the fact
Patz J, Engelberg D, Last J. 2000. The effects of changing
weather on public health. Annu Rev Public Health 21:271–307. have been brought on by heavy rains.7 The impact sheet titled “Preparing for Global Warming” at
United Nations Environment Programme (UNEP). 2007. UNEP of global warming on the safety of water supplies www.nrdc.org/globalwarming/preparedness.pdf.
2007 Annual Report. Available at: http://www.unep.org/PDF/
AnnualReport/2007/AnnualReport2007_en_web.pdf . will be most severe in developing countries, where
water treatment is less available.
© Natural Resources Defense Council May 2008 www.nrdc.org/policy Printed on recycled paper