Whose health is most vulnerable in a changing climate?

Climate change does not affect people equally. It affects some communities more than others, just as it impacts individuals differently. Indigenous communities are among the communities most impacted by climate change in North America.

To protect the most vulnerable individuals among us, we first need to know how to recognize whose health is most likely to be adversely affected by climate change. On this page, we list many of the factors that influence an individual’s vulnerability to climate-related health effects. We hope this list will encourage you to think about ways climate change can impact people differently and help you identify and safeguard individuals who are most at risk.

To protect the most vulnerable individuals among us, we first need to know how to recognize whose health is most likely to be adversely affected by climate change.

Vulnerability is “the tendency or predisposition to be adversely affected by climate-related health effects” (U.S. Global Change Research Program, pg. 29). A combination of exposure, sensitivity, and adaptive capacity influence a person’s vulnerability to climate-related health impacts. As an equation, it looks like this:

Vulnerability = exposure + sensitivity – adaptive capacity

Exposure

To identify an individual’s vulnerability to climate change, it is helpful to understand a person’s exposure to a variety of stressors.

Exposure is “contact between a person and one or more biological, psychosocial, chemical, or physical stressors, including stressors affected by climate change. Contact may occur in a single instance or repeatedly over time, and may occur in one location or over a wider geographic area” (U.S. Global Change Research Program, pg. 29).

People can be exposed to environmental stressors in a variety of ways, including:

• Working outdoors (for example, farming, ranching, and hunting and gathering traditional foods)
• Time in risk-prone locations like…
  • Areas with high levels of airborne allergens (example: areas with high amounts of pollen)
  • Areas with high levels of air pollution
• • Areas with depleted water supplies
  • Areas with vulnerable energy and transportation infrastructure
  • Flood-prone areas
  • Areas affected by drought
  • Areas affected by wildfire
  • Areas with more mosquitoes
  • Rural or isolated areas
• Responses to extreme events, such as…
  • Inability to evacuate or respond to an emergency
  • Choosing not to evacuate or respond to an emergency
• Effects of lower socioeconomic status, for example…
  • Living in poverty can increase exposure to extreme heat and air pollution (in other words, less money means less ability to afford air conditioning or ventilation systems)
  • Dependence on traditional foods from hunting and gathering can increase vulnerability to food shortages, due to changes in availability (traditional food sources like savis berry may be harder and harder to find on the Reservation as climate change shifts their habitat)
  • Limited access to treated water
  • Poorer quality infrastructure condition and access
    • Older buildings (due to increased exposure to mold, stagnant air, high temperatures from poor ventilation)
    • Vulnerable utilities, transportation, medical, and communication systems that could be disrupted in an emergency
• Compromised mobility, cognitive function, and other mental or behavioral factors
  • Reduced awareness and response ability impacts response to an emergency

Sensitivity

Understanding exposure levels is one step towards identifying who in our community is most vulnerable to climate change. Another crucial step is to identify who is most sensitive to the stressors listed above.

Sensitivity is “the degree to which a person is people or communities are affected, either adversely or beneficially, by climate variability or change” (U.S. Global Change Research Program, pg. 29).

A host of factors can influence an individual’s sensitivity to climate change. Overall health status, age, and life stage impact an individual’s sensitivity to climate change impacts. For example, exposure to airborne allergens would be more likely to impact young children than people at other ages. Older adults are generally more sensitive to extreme heat and at higher risk of contracting gastrointestinal illnesses when exposed to contaminated water. People with asthma or chronic obstructive pulmonary disease are generally more sensitive to wildfire smoke. Pregnant women are generally more sensitive to extreme heat, airborne particulate matter, and floods, which have been linked to low birth weight and preterm birth.

Overall health status, age, and life stage impact an individual’s sensitivity to climate change impacts.

Adaptive capacity

Identifying sensitivity and exposure means there is one more step needed for predicting who will be most vulnerable to climate change, and for identifying is already vulnerable. Adaptive capacity is the third ingredient of vulnerability.

Adaptive capacity is “the ability of communities, institutions, or people to adjust to potential hazards, to take advantage of opportunities, or to respond to consequences” (U.S. Global Change Research Program, pg. 29).

The following factors influence the ability of individuals to adjust to potential hazards, take advantage of opportunities, and respond to impacts:

• Socioeconomic status can influence a person’s and a community’s ability to adapt to climate change (For example, living in poverty can reduce a person’s access to information and ability to respond)
• Condition and limited accessibility of infrastructure (For example, living in a house in disrepair can expose a person to more environmental hazards from climate change)
• Access to quality health care
• Demographic characteristics
• Skills, knowledge, experience, and social cohesion of a community
• Social isolation

Everyone is important in our community, and we must work diligently to protect all community members as the climate changes. Some people require extra support and attention as temperatures warm and precipitation patterns shift. Our most vulnerable community members have higher levels of exposure to stressors, more sensitivity to stressors, and have less adaptive capacity. Understanding who is most vulnerable is a first step in building programs to increase our community’s resilience.

Learn more about our decisions, our health, and climate change.

This page is a summary of some of the information found in U.S. Global Change Research Program’s 2016 report entitled, “The Impacts of Climate Change on Human Health in the United States” found by following this link.