FUTURE: Rising sea levels and at-risk populations in Thurston County

11/7/2020

Sea level projections in Thurston County from 2016 to 2100. Source: 2012 report of the U.S. National Research Council.

Climate changes and the local environment:

A 2016 Climate Central study revealed that human actions are resulting in rising global sea levels. As a result, some primary concerns are how populations, buildings, infrastructure, land and contamination risks will be affected by these rising sea levels. For Thurston County, there is an increased risk of flooding, especially in the most vulnerable areas that closely line large bodies of water.

Thurston County, home to the city of Olympia, rests on the bank of the Puget Sound inlet. A U.S. National Research Council report projected a 9% risk of at least one flood over 4ft occurring sometime between today and 2050 in the Olympia area. By the year 2060, this percentage is projected to rise to 24% before drastically increasing to 62% by the year 2070 with flood levels expected to rise well above 4ft.

The frequency and intensity of heavy rain events is also projected to increase according to a 2015 study conducted as part of the Climate Impacts Group’s “State of Knowledge” series that focused on the Puget Sound area. Increased precipitation is directly linked to increasing global air temperatures that will lead to more freshwater inflows into the Puget Sound, particularly during winter months. Additionally, rising air temperatures would increase the likelihood of harmful algal blooms in the ecosystem.

While Washington state as a whole is at risk to the effects of climate change, areas such as Thurston county that are near central bodies of water are particularly vulnerable. Rising temperatures and sea levels will directly impact the Puget Sound and its surrounding areas. The effects of climate change will surely have a range of sociological, ecological and economic impacts on Thurston county.

Areas susceptible to flooding and contamination risk from various threats including EPA sites, RADINFO sites, hazardous waste sites, sewage plants. Source: EPA.

How we know:

These projections rely primarily on two tools that are freely accessible online: the “State of Knowledge Report - Climate Change in Puget Sound” and the Surging Seas, Risk Finder Website.

The “State of Knowledge” series summarizes research on the probable effects of climate change on the water, lands and people of the Puget Sound. The synthesized work was created by the Climate Impacts Group, which aims to increase understanding and awareness of climate change through sharing information and conducting scientific studies. Data, projections and relevant research were all used to compile this report.

The Surging Seas tool aims to provide accessible, science-based, localized information to help people better understand and respond to the climate crisis as it specifically relates to rising sea levels. The National Oceanic and Atmospheric Association (NOAA) provides Surging Seas with accurate coastal elevation and tide station data. More scientific data was pulled from 2012 U.S. National Research Council records while population-specific data was obtained through the 2010 U.S. Census.

Public opinion and risk perception of adults in Thurston county on global warming in 2016. Source: Yale Climate Opinion Maps.

Human Consequences:

Flooding and rising sea levels disproportionately harm vulnerable populations like the elderly, children, and people experiencing homelessness. The Thurston county homeless census found that 800 individuals were homeless or lived in emergency or transitional housing in 2019. While this is a slight decrease since the year prior, it is still a significantly large number. Many of these homeless individuals are unsheltered and positioned to be hit the hardest in the case of flooding or any other major climate events.

In addition to vulnerable communities being at risk from elevating sea levels, the effects of climate change will impact other areas as well. Agriculture lies along many rivers, infrastructure is vulnerable, homeowners and their property are at risk, and clean water sources may be contaminated. Climate change has the capacity to influence change in many areas and, eventually, everyone will be considered vulnerable regardless of their socioeconomic status.

When surveyed in 2016, residents of Thurston county had a higher than average awareness of climate issues, yet a lower than average concern for the personal toll that global warming will have on them.