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For further information and to access other CCSP information, 

go to <www.climatescience.gov>

Climate Event Examples of Possible Impacts on 

Health

Likelihood of 

Impacts Given 

Climate Event 

Occurs

Potential Adaptation Strategies

More heat 

waves and 

extreme high 

temperatures

Heat stress/stroke. 

Uncertain impacts on mortality

Very likely in 

Midwest and 

northeast urban 

centers

Early watch and warning systems and installation of cooling 

systems in buildings

Changes in 

precipitation, 

especially 

extreme precipitation

contaminated water and food supplies with associated gastrointestinal illnesses including salmonella 

and giardia

Likely in areas 

with out-dated or 

over-subscribed 

water treatment 

plans

Improve insfrastructure to 

guard against combined sewer 

overflow; public health response to include “boil water” 

advisories

Hurricane and 

storm surge

Injuries from flying debris and 

drowning / exposure to contaminated flood waters and to mold 

and mildew / exposure to carbon 

monoxide poisoning from portable 

generators

Likely in coastal 

zones of the 

southeast Atlantic and the Gulf 

Coast

Increase knowledge and awareness of vulnerability to climate 

change; public health advisories in immediate aftermath of 

storm; coordinate storm relief 

efforts to insure that people 

receive necessary information 

for safeguarding their health

Temperaturerelated effects 

on ozone

Ozone concentrations more likely 

to increase than decrease; possible 

contribution to cardiovascular and 

pulmonary illnesses, including 

exacerbation of asthma and chronic 

obstructive pulmonary disorder 

(COPD) if current regulatory standards are not attained

Likely in urban 

centers in the 

mid-Atlantic and 

the northeast

Public warning via air quality 

action days; encourage public 

transit, walking and bicycling 

to decrease emissions

Wildfires Degraded air quality, contributing 

to asthma and COPD aggravated

Likely in California, the Intermountain West, 

the southwest and 

the southeast

Public health air quality advisories

Potential Adaptation Strategies for Moderating Impacts 

of Climate Change on Human Health and Welfare

Climate variability and change challenge 

even the world’s most advanced societies. 

At a very basic level, climate affects the 

costs of providing comfort in our homes 

and work places. A favorable climate can 

provide inputs for a good life: adequate 

fresh water supplies; products from the 

ranch, the farm, the forests, the rivers and 

the coasts; pleasure derived from tourist 

destinations and from nature, biodiversity, 

and outdoor recreation. 

Climate not only supports the provision 

of many goods and services, but also affects the spread of some diseases and the 

prevalence of other health problems. It is 

also associated with threats from extreme 

events and natural disasters such as tropical storms, riverine and coastal flooding, 

wildfires, droughts, wind, hail, ice, heat, 

and cold.

Human Health and Welfare in a 

Changing Climate

Summary and Findings of the U.S. Climate Change 

Science Program

1. This paragraph is drawn particularly from SAP 3.3

Middle image on front page from freeimages.co.uk, other front page images from NOAA’s Portland OR forecast office

The information in this factsheet is drawn from CCSP’s Synthesis and Assesment Products 4.6 (Analyses of the Effects of Global Change on Human Health and Welfare and 

Human Systems) and 3.3 (Weather and Climate Extremes in a Changing Climate).
United States 

Census Regions

Climate-Related Impacts

early snowmelt Degraded 

Air quality

Urban 

Heat 

Island

Wildfires Heat 

Waves

Drought Tropical 

Storms

Extreme 

rainfall with 

Flooding

Sea Level 

Rise

New England

ME VT NH MA RI CT • • • • • • •

Middle-Atlantic

NY PA NJ • • • • • • • •

East North Central

WI MI IL IN OH • • • • • •

West North Central

ND MN SD IA NE 

KS MO

• • • • •

South Atlantic

WV VA MD NC SC 

GA FL DC

• • • • • • • •

East South Central

KY TN MS AL • • • •

West South Central

TX OK AR LA • • • • • • • •

Moutnain

MT ID WY NV UT 

CO AZ NM

• • • • • •

Pacific

AK CA WA OR HI • • • • • • • • •

Health effects related to climate change will vary by 

region. 

For the continental United States:

• the northern areas are likely to experience the largest 

increases in average temperatures; 

they will also bear the brunt of 

increases in ground-level ozone and 

other airborne pollutants. 

• Because Midwestern and 

Northeastern cities are generally 

not as well adapted to the heat as 

Southern cities, their populations 

are likely to be disproportionately 

affected by heat related illnesses as 

heat waves increase in frequency, 

severity, and duration. 

• The range of many vectors (eg. 

insects, rodents) is likely to extend 

northward and to higher elevations. 

For some vectors, such as rodents 

associated with Hantavirus, ranges 

are likely to expand, as the precipitation patterns under 

a warmer climate enhance the vegetation that controls 

the rodent population. 

• Forest fires with their associated decrements to air 

quality and pulmonary effects are likely to increase in 

frequency, severity, distribution, and duration in the 

Southeast, the Intermountain West and the West.

How Is Human Welfare Related to Health 

And What Are The Impacts of Climate 

Change?

The terms human welfare, quality of life, and wellbeing are often used interchangeably. There is a shared 

understanding that all three terms refer to aspects of life 

that improve living conditions and reduce chances of 

injury, stress, and loss.

Human well-being is typically defined and measured as a 

function of several dimensions: 

1) economic conditions, 

2) natural resources and amenities, 

3) human health, 

4) public and private infrastructure, including 

 transportation systems, 

5) government and public safety and 

6) social and cultural resources. 

Climate change will likely 

have impacts across all of 

these dimensions – both 

positive and negative. 

In addition, the positive 

and negative effects of 

climate change will affect 

broader communities, as 

networks of households, 

businesses, physical 

structures, and institutions 

are located together across 

space and time.

One of the most significant 

ways in which social, 

economic, and natural systems are likely to experience 

climate change is through a change in weather and climate 

extremes. Changes in climate extremes (such as flooding 

rain events, heatwaves etc), are already observed to be 

having impacts. And while extremes can have positive or 

negative effects, on balance, because systems have

adapted to their historical range of extremes,

the majority of 

the impacts of 

events outside

this range are 

expected to be 

negative.1 The 

cost to human 

welfare in the 

case of extremes 

include such 

examples as 

increased 

extreme 

precipitation leading to local flooding and contamination 

of water supplies - considered a very likely outcome of 

global warming nationwide; fewer coldwaves are also 

expected to occur - conferring some benefits, including 

reduced snow removal, and at the same time also limiting 

snow- and cold-based recreation.

How Will Climate Change Impact Human 

Health in the U.S.?

The United States is a highly developed country with a 

wide range of climates. While there may be fewer cases 

of illness and death associated with climate change 

in the United States than in the developing world, we 

nevertheless anticipate increased costs to human health 

and well being. Greater wealth and a more developed 

public health system and infrastructure (e.g., water 

treatment plants, sewers, and drinking water systems; 

roads, rails and bridges; flood control structures) will 

continue to enhance our capacity to respond to climate 

change. Similarly, governments’ capacities for disaster 

planning and emergency response are key assets that 

should allow the United States to adapt to many of the 

health effects associated with climate change

Some Impacts of Climate Change on Health:

It is very likely that heat-related death and illness will 

increase over the coming decades. 

According to the U.S. Census, the U.S. population is aging; Older adults, very young children, and persons with compromised 

immune systems are vulnerable to 

temperature extremes. 

This suggests that temperaturerelated death and illness are likely 

to increase. Similarly, heat-related 

death affects poor and minority 

populations disproportionately, in part due to lack of 

air conditioning. 

There will likely be an increase in the spread of several food- and water-borne diseases among susceptible 

populations 

The extent of this increase depends on the survival, persistence, habitat range and transmission of agents of disease (e.g. bacteria or viruses) under changing climate and 

environmental conditions. The primary 

climate-related factors that affect these 

agents, or pathogens, 

include temperature, 

precipitation, extreme 

weather events, and 

shifts in their ecological regimes. However, the impact of 

climate on food- and water-borne pathogens will seldom 

be the only factor determining the burden of human injuries, illness, and death.

Climate change is very likely to 

accentuate the disparities already 

evident in the American health care 

system. Many of the expected health 

effects are likely to fall disproportionately on the poor, the elderly, 

the disabled, and the uninsured. The 

most important adaptation to ameliorate health effects from climate 

change is to support and maintain the 

United States’ public health infrastructure.

limate change will result in regional differences 

in impacts in the United States not only due to 

a regional pattern of changes in climate but the 

regional nature of our communities in adapting to 

 these changes 

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