Climate Change, Equity, & Health

March 6, 2017

Denver Department of Environmental Health

“Climate change is the greatest public health challenge of the 21st century”.  [1]

Over the past decade, rapid climate change has become the most defining concern of the 21st century. Global emissions of climate-altering greenhouse gases (GHGs) are rising, along with the temperature of the atmosphere and oceans. As a result, communities worldwide are experiencing record temperatures, increased frequency of drought, severe flooding, wildfires, and a decline in air quality.  In fact, 2016 was the hottest year on record, eclipsing the previous hottest year of 2015 and 2014 before that.[2]

These heat-related events can result in human health impacts such as increased asthma and respiratory illnesses, heart disease and heart attacks, exacerbation of existing medical conditions including diabetes, obesity and cognitive illness, and premature death.[3] Rising temperatures may reduce air quality by increasing the formation of ground-level ozone, which is a key component of smog. This may be problematic in areas such as the Denver-Metropolitan and North Front Range, which struggle to meet the national ozone standards.[4]

However, the health risks and impacts of climate change are not equally or fairly distributed across people or communities.  [5]  In the U.S., low-income communities and communities of color suffer substantially higher disease burdens and lower life expectancies than wealthier and white populations. For example, the rate of diabetes among the poor is 1.5 times higher than of those who are not poor. Diabetes increases one’s sensitivity to extreme heat.  Deaths from heart disease and stroke are higher for Blacks than any other ethnic group. Heart disease also increases sensitivity to heat stress. And adults with a high school education or less are 8 times more likely to report their health as ‘fair or poor’ than those with a college education. [6] Education and poverty are linked, and those living in poverty often lack access to air conditioning. Living conditions differ by place, race and income due to factors including historical disinvestment, housing discrimination, and higher pollution burdens in communities of color.  These factors mean that climate change has the potential to create greater ‘health inequity’, or differences in health outcomes between groups of people that are avoidable and preventable.

The City of Denver developed a Heat Vulnerability Index Map to understand which neighborhoods have residents that might be more vulnerable to extreme heat events due to a number of factors, including socioeconomic, built environment, and demographic factors. Some neighborhoods have lower amounts of tree cover for cooling, and higher areas of impervious surface like asphalt and concrete, which trap heat and raise temperatures. There are also neighborhoods with higher numbers of elderly people, people who live alone, and those with physical or cognitive disabilities who might face difficulty accessing cooler areas during extreme heat events. Finally, the map shows neighborhoods with higher numbers of people that live in poverty, which may indicate less access to air conditioning in their homes and access to a personal vehicle to get to cooling stations in extreme heat events.

The City of Denver is using this information to target planning and resources to those residents at highest risk during extreme heat events, to reduce health inequity due to climate change among Denver’s most vulnerable citizens.

In addition, the Denver Vital Signs newsletter published a recent issue on “The Health Impacts of Climate Change” to understand how climate change affects the health of Denver residents including increased particulate matter and other pollutants in the air, poor air quality, and more frequent hospital visits for asthma treatment for children in particular.

One of the primary sources of greenhouse gas emissions is motor vehicles, according to the 2015 Denver Climate Action Plan. Denver is working to reduce greenhouse gases in the City by promoting more “active transportation”, including biking, walking and transit use.  Reduced-rate transit passes are currently available to seniors, students, and those with disabilities, and efforts are underway to expand discounted pass access to those with low incomes.  City of Denver employees can purchase reduced-rate “Eco-passes” to use transit or “B-cycle” passes for bike sharing.  Denver Safe Routes to School supports local schools to increase student walking and biking with bike training programs, walking school buses, and Walk and Bike to School Days. And the newly adopted “Denver Ultra Urban Green Infrastructure Guidelines” allow City and private developers to incorporate more green treatments such as stormwater planters, green alleys, and tree trenches in urban areas to reduce local flooding and ambient temperatures and improve air quality.

These efforts can not only help reduce the human health impacts of climate change, but reduce the inequitable impacts of climate change on the most vulnerable members of our community.

[1] Center for Climate Change & Health

[2] Hot. Hot. Hot. Third Straight Year of Record Temperatures. Denver Post, 1-19-17.

[3]  Climate Change and Human Health Trends

[4] United States Environmental Protection Agency, What Climate Change Means for Colorado (August 2016). Colorado Department of Public Health & Environment, “Ozone information,” last accessed December 2016.

[5] Climate Change and Health Equity

[6] Climate Change and Health Equity