Climate migration is one example of how Missoula County will ultimately be affected not only by our changing climate, but by the impacts of climate change elsewhere in the country and world.
Missoula County’s population is increasing. From 2010-2017 the county grew by 7.3%, and it is projected to grow an additional 21.8% by 2043, bringing the total population to more than 142,000 residents. These estimates are independent of the impacts of climate change on the flow of migrants to and from Missoula County.
In order to understand the true impacts of climate change in Missoula County, we need to know how it will affect the county’s population. Will current residents move away, fed up with longer and longer periods of wildfire smoke? Or will people from other parts of the country that are experiencing even more disastrous climate impacts flock to Missoula County as a refuge?
To support the Climate Ready Communities process, Adaptive Hydrology, LLC performed a preliminary analysis of the impacts of climate change on Missoula County’s population. The bottom line: Missoula County will likely experience an increase in population due to climate change. Without knowing the magnitude of this growth, or how it will be distributed throughout the county, it is impossible to assess its full implications; however, we are aware in a general sense of the challenges and opportunities presented by population growth.
Climate migration is one example of how Missoula County will ultimately be affected not only by our own changing climate, but by the impacts of climate change elsewhere in the country and world. As another example, disruption of energy systems (such as damage to oil refineries due to hurricanes and sea level rise) could affect energy prices and, by extension, the price of food and consumer products due to increased transportation costs. Disruption of food systems in other parts of the country could also affect food prices and food availability for Missoula County residents, and could increase our reliance on locally grown food. While critical, these ‘reverberation’ effects are for the most part beyond the scope of this assessment.
In order to understand the true impacts of climate change in Missoula County, we need to know how it will affect the county’s population. Will current residents move away, fed up with longer and longer periods of wildfire smoke? Or will people from other parts of the country that are experiencing even more disastrous climate impacts flock to Missoula County as a refuge?
To support the Climate Ready Communities process, Adaptive Hydrology, LLC performed a preliminary analysis of the impacts of climate change on Missoula County’s population. The bottom line: Missoula County will likely experience an increase in population due to climate change. Without knowing the magnitude of this growth, or how it will be distributed throughout the county, it is impossible to assess its full implications; however, we are aware in a general sense of the challenges and opportunities presented by population growth.
Climate migration is one example of how Missoula County will ultimately be affected not only by our own changing climate, but by the impacts of climate change elsewhere in the country and world. As another example, disruption of energy systems (such as damage to oil refineries due to hurricanes and sea level rise) could affect energy prices and, by extension, the price of food and consumer products due to increased transportation costs. Disruption of food systems in other parts of the country could also affect food prices and food availability for Missoula County residents, and could increase our reliance on locally grown food. While critical, these ‘reverberation’ effects are for the most part beyond the scope of this assessment.
Explore how climate migration and population change creates vulnerabilities in the following sectors given climate change:
buildings and landscaping.
Population growth will increase the need for new housing and commercial buildings. City and County Growth Policies suggest a need for approximately 12,000 to 17,000 new housing units in county by 2035. Climate migration will increase this need by an unknown amount. Housing affordability is an increasing concern in the county as the population grows and housing prices increase faster than incomes.
In recent years, construction costs have risen in the Missoula area due to increases in the price of materials and a shortage of skilled labor, exacerbating the challenge of housing affordability. Issues of housing affordability can lead to increased development in areas where the cost of land is lower, which may be more vulnerable to climate impacts such as wildfires or flooding. The pressure to build homes quickly and to keep costs low also has the potential to conflict with the need to build high-quality, well-insulated homes that will better protect their occupants from the impacts of climate change such as heat and wildfire smoke.
The full vulnerability grid for Buildings, for all impacts, is shown below.
In recent years, construction costs have risen in the Missoula area due to increases in the price of materials and a shortage of skilled labor, exacerbating the challenge of housing affordability. Issues of housing affordability can lead to increased development in areas where the cost of land is lower, which may be more vulnerable to climate impacts such as wildfires or flooding. The pressure to build homes quickly and to keep costs low also has the potential to conflict with the need to build high-quality, well-insulated homes that will better protect their occupants from the impacts of climate change such as heat and wildfire smoke.
The full vulnerability grid for Buildings, for all impacts, is shown below.
business, recreation, and tourism.
When it comes to the county’s economy, population growth will result in both benefits and challenges. More people means a more competitive labor market, more new businesses, and possibly diversification of the economy. It can also strain resources and increase crowding, with potential negative repercussions for tourism since access to uncrowded natural areas and recreational opportunities are among the area’s key attractions for tourists. We are unable to weigh these pros and cons due to great uncertainty in the scale and speed of the growth we will experience due to climate change, and how it will interact with the population growth projected for our county independent of climate change.
The full vulnerability grid for Business, Recreation, and Tourism, for all impacts, is shown below.
The full vulnerability grid for Business, Recreation, and Tourism, for all impacts, is shown below.
energy and water infrastructure.
With increased population comes increased demand on water infrastructure, including water supply and wastewater treatment. More people use more energy, increasing the demand for electricity and natural gas. Utilities will need to meet this additional demand by developing or purchasing additional energy resources, with costs ultimately passed through to consumers. Increase in extreme temperature events may increase peak loads on utility infrastructure, requiring additional, expensive, and typically nonrenewable infrastructure to meet only occasional loads (e.g. peaking plants).
The full vulnerability grids for Energy and Water Infrastructure, for all impacts, is shown below.
The full vulnerability grids for Energy and Water Infrastructure, for all impacts, is shown below.
Forests and terrestrial ecosystems.
Increased population will lead to increased development pressure in the wildland-urban interface (WUI), which contributes to ecosystem fragmentation. It also means more people using the forest for recreation (e.g. hiking and camping), increasing the likely spread of invasives and diseases from other regions.
The full vulnerability grids for Forests and Terrestrial Ecosystems, for all impacts, is shown below.
The full vulnerability grids for Forests and Terrestrial Ecosystems, for all impacts, is shown below.
land use planning and transportation.
Missoula County’s 2016 Growth Policy and the City of Missoula’s 2015 ‘Our Missoula’ Growth Policy are both based around official population growth projections, which do not consider the additional population growth likely as a result of climate change. In May 2019, the county adopted a land use map for the Missoula area which is intended to guide growth over the next 20 years. While population projections are always uncertain, climate change adds an additional layer of uncertainty and makes long-term planning more challenging.
Increased population growth interacts with land use planning and transportation to affect many of the other sectors described in this report. Population growth, in conjunction with planning decisions, can lead to development in the WUI, in flood zones, and on agricultural lands; can put pressure on groundwater resources and emergency services; and can increase impacts on local air quality and greenhouse gas emissions from transportation. Transportation infrastructure may contribute to the urban heat island effect.
The full vulnerability grids for Land Use Planning and Transportation, for all impacts, is shown below.
Increased population growth interacts with land use planning and transportation to affect many of the other sectors described in this report. Population growth, in conjunction with planning decisions, can lead to development in the WUI, in flood zones, and on agricultural lands; can put pressure on groundwater resources and emergency services; and can increase impacts on local air quality and greenhouse gas emissions from transportation. Transportation infrastructure may contribute to the urban heat island effect.
The full vulnerability grids for Land Use Planning and Transportation, for all impacts, is shown below.