Joe Casola, Climate Impacts Group, University of Washington
Michael Chang, Makah Tribe
Jennifer Cuhaciyan, Bureau of Reclamation
Meghan Dalton, Oregon State University
Scott Lowe, Boise State University
Gary Morishima, Quinault Indian Nation
Philip Mote, Oregon State University
Alexander (Sascha) Petersen, Adaptation International
Gabrielle Roesch-McNally, USDA Forest Service
Emily York, Oregon Health Authority
Beatrice Van Horne, USDA Forest Service, Northwest Climate Hub
Natalie Bennett, Adaptation and Assessment Analyst
Christopher W. Avery, Senior Manager
Susan Aragon-Long, Senior Scientist
<b>May</b>, C., C. Luce, J. Casola, M. Chang, J. Cuhaciyan, M. Dalton, S. Lowe, G. Morishima, P. Mote, A. Petersen, G. Roesch-McNally, and E. York, 2018: Northwest. In <i>Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment</i>, Volume II [Reidmiller, D.R., C.W. Avery, D.R. Easterling, K.E. Kunkel, K.L.M. Lewis, T.K. Maycock, and B.C. Stewart (eds.)]. U.S. Global Change Research Program, Washington, DC, USA, pp. 1036–1100. doi: 10.7930/NCA4.2018.CH24
Organizations and volunteers that make up the Northwest’s social safety net are already stretched thin with current demands. Healthcare and social systems will likely be further challenged with the increasing frequency of acute events, or when cascading events occur. In addition to an increased likelihood of hazards and epidemics, disruptions in local economies and food systems are projected to result in more chronic health risks. The potential health co-benefits of future climate mitigation investments could help to counterbalance these risks.
Linkage Between Climate Change and Regional Risks
Over the last few decades, an increase in climate-related extreme events has led to an increase in the number of emergency room visits and hospital admissions. Warmer and drier conditions during summer have contributed to longer fire seasons.140 Wildfire smoke can be severe, particularly in communities in the eastern Northwest.154 Smoke events during 2004–2009 were associated with a 7.2% increase in respiratory hospital admissions among adults over 65 in the western United States.155 In Boise, Idaho, 7 of the last 10 years have included smoke levels considered “unhealthy for sensitive groups” (including children) for at least a week during the fire season,154 causing some cancellation of school-related sports activities (Ch. 13: Air Quality, KM 2).
During extreme heat events in King County, Washington, from 1990 to 2010, heat-related hospital admissions were 2% higher and deaths 10% higher than the average for that period,156,157 with an increased demand for emergency medical services for children, outdoor laborers, and the elderly.158 The state of Oregon has also recorded spikes in heat-related emergency room visits.159 In particular, agricultural workers are at increased risks for heat-related injuries because they work outside during the summer harvest season.160
In the last several years, the region has seen an increase in some infectious diseases. An increase in Lyme disease cases is associated with rising temperatures and changing tick habitat.161 The Washington Department of Health’s vector surveillance program has observed an earlier onset of West Nile virus-carrying mosquitoes, likely associated with higher temperatures, and an increasing number of human infections, with some resulting in fatalities.162 Before 1999, cryptococcal infections were limited to the tropics, but Cryptococcus gatti, the species that causes these infections, is now established in Northwest soil, with 76 cases occurring in Oregon in 2015.163 The Oregon Health Authority recorded spikes in cases of Salmonella and E. coli during months with extreme heat in 2015.163 A large outbreak of Shigellosis (a bacterial diarrheal disease) occurred in late 2015, affecting a large number of homeless people in the Portland Metro region; this outbreak was associated with unusually extreme precipitation.164
Changes in drought conditions and increased water temperatures have increased the potential for freshwater harmful algal blooms in recreational waters,165 although there is little capacity among state health departments to monitor and track harmful algal blooms. Toxins from marine harmful algal blooms can accumulate in shellfish, leading to illnesses for those who eat them.166 In 2015, during the largest harmful algal bloom ever observed off the West Coast from California to Alaska, high levels of domoic acid led to the closure of shellfish harvesting in much of the Northwest (Box 24.7).167
Children and youth, in general, will likely experience cumulative physical and mental health effects of climate change over their lifetimes168 due to increased exposure to extreme weather events (such as heat stress, trauma from injury, or displacement) and increased toxic exposures (such as increased ground-level ozone pollution in urban areas or increased risk of drinking water contamination in rural areas). Beginning at the fetal development stage, environmental exposures to air or water pollution can increase the risk of impaired brain development,169 stillbirth,170 and preterm births.171,172 Infants and children can be disproportionately affected by toxic exposures because they eat, drink, and breathe more in proportion to their body size.173 Natural disasters, as well as gradual changes (like changing landscapes and livelihoods) caused by climate stressors, increase the risk of anxiety, depression, and post-traumatic stress disorder (PTSD).174 Evidence shows that exposure to both pollution and trauma early in life is detrimental to near-term health, and an increasing body of evidence suggests that early-childhood health status influences health and socioeconomic status later in life.175,176
Future Climate Change Relevant to Regional Risks
More frequent wildfires and poor air quality are expected to increase respiratory illnesses in the decades to come (Ch. 13: Air Quality, KM 2). Airborne particulate levels from wildfires are projected to increase 160% by mid-century under a lower scenario (RCP4.5),177 creating a greater risk of smoke exposure through increasing frequency, length, and intensity of smoke events.177
Projected increases in ground-level ozone (smog), small particulate matter (PM2.5), and airborne allergens178 can further complicate respiratory conditions (Ch. 13: Air Quality, KM 1). There is a well-documented link between exposure to air pollution and risk of heart attack, stroke, some types of cancer, and respiratory diseases,179 all of which are leading causes of death in the Northwest.180 The portion of each health condition attributed to air pollution is unknown, but the social and economic costs of these diseases are large. In Oregon, the medical costs associated with heart attacks in 2011 alone were over $1.1 billion, and those associated with stroke were $254 million ($1.2 billion and $269 million, respectively, in 2015 dollars).181
Increases in average and extreme temperatures are projected to increase the number of heat-related deaths.182,183 Mid-century climate in Portland, Oregon, under a mid-high scenario (RCP6.0) may result in more than 80 additional heat-related deaths per year, although this figure does not account for future population growth or possible adaptations.184
Future extreme precipitation events could increase the risk of exposure to water-related illnesses as the runoff introduces contaminants and pathogens (such as Cryptosporidium, Giardia, and viruses) into drinking water.185 In the Puget Sound, under a mid-high emissions scenario (SRES A1B), local atmospheric heating of surface waters is projected to result in 30 more days per year that are favorable to algal blooms and an increased rate of bloom growth.186
Income loss associated with climate impacts will likely increase the risk of people experiencing food insecurity (see Key Message 1).187 As an example, in early 2016 a harmful algal bloom impacted the local economy in Long Beach, Washington, which is largely dependent on shellfish, tourism, and service industries. The local Food Bank recorded an almost 25% increase in the number of families requesting assistance in the six months that followed.188 Climate-driven hardships can also affect mental health, resulting in outcomes ranging from stress to suicide.189 Oregon, Washington, and Idaho all rank among the top 10 states in terms of prevalence of mental illness and lowest access to mental health care.190 Serious mental illness costs the U.S. economy more than $193 billion in lost earnings each year ($224 billion in 2015 dollars).191 Tribes and Indigenous peoples face multiple physical and mental health challenges related to climate change, with impacts to subsistence and cultural resources (see Key Messages 2 and 5) (see also Ch. 15: Tribes, KM 2). Some of these health concerns are described in a recent project created by members of the Confederated Tribes of Warm Springs.192 Tracking climate stressors and training related to climate anxiety and post-disaster trauma is not widespread among the region’s health workforce.193
Challenges, Opportunities, and Success Stories for Reducing Risk
Existing environmental health risks are expected to be exacerbated by future climate conditions,187 yet over 95% of local health departments in Oregon reported having only partial-to-minimal ability to identify and address environmental health hazards.194
With funding from the Centers for Disease Control and Prevention, Oregon has been able to make some headway on assessing climate change vulnerabilities195 and recently released a statewide climate and health resilience plan.196 Five local health jurisdictions in Oregon are some of the first in the country to complete local climate and health adaptation plans. Interventions to address community-identified priorities range from providing water testing for domestic well users in drought-prone areas to quantifying the health co-benefits of proposed transportation investments. The Washington Department of Health has also added a climate program to begin integrating climate considerations into the state’s public health system. In addition, the Drinking Water State Revolving Fund has made it possible for water system managers and utilities to apply for low interest loans that support resilience projects. Washington’s Marine Biotoxin Program, also housed within the Department of Health, operates an early warning system in partnership with academics, organizations, and citizen scientists to increase the geographic breadth and frequency of sampling for harmful algal blooms that could compromise the safety of shellfish. Public health practitioners in southeastern Idaho have formed a new working group with tribes, universities, local jurisdictions, businesses, and nonprofits to develop strategies for mitigating health impacts of wildfire smoke and water insecurity.
Together, Northwest states have launched the Northwest Climate and Health Network for public health practitioners to share resources and best practices. Idaho, Oregon, and Washington all have syndromic surveillance systems that provide near-real-time data from emergency room visits. These health data have the potential to be layered with climate and environmental data (such as temperature and air quality data), but such analysis has not been carried out on a broad scale.
Incorporating more health and wellness considerations into climate decision-making can increase a community’s overall resilience (Ch. 14: Human Health, KM 3). For example, preserving the ecological functions of an area can also promote tribal and Indigenous health, while investing in active transportation and green infrastructure can also improve air quality and increase physical activity.197
Communities with higher rates of illness and death often have less adaptive capacity and are more vulnerable to climate stressors.198 Many people living in the Northwest already struggle to meet basic needs that could serve as protective factors—and these numbers could increase. For example, roughly 1 in 5 children in the region live in a food-insecure household199,200,201 and are already at higher risk of poor health outcomes like asthma and diabetes.202 Both the states of Washington and Idaho have had some of the largest increases in homeless populations in the United States, and in 2016, Oregon had the highest rate of unsheltered homeless families with children.203 People lacking adequate shelter face increased climate risks (such as direct exposure to extreme heat or winter storms), while also having increased vulnerability (such as poorer health and less access to resources).
Displacement and increased migration to the Northwest could place increasing pressures on housing markets, infrastructure, and health and social service systems.128 However, the role of climate as a driver for migration to the Northwest is speculative; current population forecasts do not yet account for climate factors.204
Public health leaders in the Northwest are working to modernize health systems to better respond to and prepare for complex and emerging health risks. Coordinated Care Organizations (CCOs) in Oregon, which serve as Medicaid insurance providers, are beginning to invest in certain climate protections for members. For example, some are covering the cost of air conditioning units for patients at risk of heat-related illnesses, ensuring patients can remain in their homes.205 More studies would be needed to fully account for the cost savings associated with these kinds of health-related services.