Project Summary

Alaskan Native villages are vulnerable to environmental risks, experiencing escalating rates of erosion, flooding, and failing infrastructures, with a cumulative cost in the millions of dollars. There is a critical need to develop short and long-term solutions that address the impacts of climate change and support Alaskans residing in environmentally threatened communities. Predicting the effects of climate change is challenging as most of the climate risks and impacts currently documented are based on historical climate events and patterns; these are no longer reliable for predicting future climate risks. 

Two Bears Environmental Consulting, LLC., completed an Environmental Risk Assessments for three Native Alaska Communities located in the Yukon Kuskokwim Delta in Southwest Alaska. One community, Newtok was the first Alaskan Native Community to be relocated due to climate change while two other communities, Chefornak and Napakiak were evaluating their options to protect in place or relocate. Climate sensitivities were projected based on future climates (RCP 8.5) for each decade from baseline through 2100 as predicted from the IPCC, capturing both gradual onset climate change and extreme events at the village scale using accepted forward-thinking climate practices.

This assessments provided projected future climates, such as changes in a) precipitation, b) minimum, mean, and maximum temperatures, c) soil temperatures, d) soil water content, and e) snow depths, that can be used to develop building criteria for resilient infrastructure. Extreme wind and precipitation storm events and extreme temperatures are also provided for a range of Annual Return Intervals; this data can be used to develop building criteria for infrastructure according to its expected lifespan. For example, a structure with an expected lifespan of 25 years would ideally be constructed to meet or exceed a projected future 25-year event.

The assessments projected significant changes in slow onset climate variables. Annual mean, minimum, and maximum temperatures increased. The increase in temperatures will cause an increase in soil temperatures impacting the permafrost; the days of frozen tundra is projected to decrease. Although the annual average precipitation is projected to increase, snowpack is projected to decrease due to the higher temperatures. Projected increases in extreme rainfall events combined with increases in extreme wind speeds suggest the potential of higher intensity storms. On the other hand, with increased temperature and precipitation, the vegetation growth is expected to increase with longer growing seasons, extending the time available for gathering food. Also, fuel for heating needs may decrease.

Newtok – Relocation to Mertarvik. Climate changes have already had significant impacts on the Village of Newtok; Ninglick River erosion has accelerated due to extreme weather events, thawing permafrost, and deceases in Arctic Sea ice which has significantly impacted the livability of the village and put residents in danger. Due to the devasting impacts of climate change, in 1994, Newtok voted to relocate their village, By 2006 they had selected and obtained a new site, which they named Mertarvik, and began coordinating relocation efforts. Construction began at Mertarvik in 2009. Community members wanted to know what the climate might look like in 20, 50, or 100 years so they can build a village that will withstand future climates.

The assessment was completed to inform decisions for the Village of Newtok’s new Mertarvik site, e.g., number of culverts to withstand future extreme rainfall events. Climate sensitivities were projected based on future climates (RCP 8.5) for each decade from baseline through 2100 as predicted from the IPCC, capturing both gradual onset climate change and extreme events at the village scale using accepted forward-thinking climate practices. Although the effects of a changing climate will still impact Mertarvik, projected flooding and erosion risks at the new site are low. 

Napakiak – Relocate. Climate change is likely to affect the livability of the Village of Napakiak, with projected flooding and erosion impacting critical infrastructure and warmer, wetter climates influencing traditional lifestyles. This assessment provides data on the magnitude and timing of these impacts, enabling community members to be proactive in developing mitigation options that will shape a resilient community for future generations. 
The Village of Napakiak is projected to have increased flooding, with 50‐year flood events (ARI 50) of over 7 feet. Erosion is predicted to continue at an accelerated rate with loss of critical infrastructure by 2030, including the school and its fuel tanks, homes, commercial buildings, and the south part of the airport. By 2050, it is projected that 80% of the Village of Napakiak will be lost to erosion, including the entire airport; 100% of the Village is projected to be lost by 2070, including the site of the new hovercraft. and barge landing.

The combined flooding and erosion risks suggest that ‘protect‐in‐place’ may not be a viable option for Napakiak; at least not without significant intervention such as building a protective sea wall. Napakiak may need to consider moving buildings away from the erosion risk zone or moving the entire village to a new site. Extending the road and services and moving threatened buildings away from the erosion risk areas may be a logical and cost-effective option. However, most of the areas available to relocate the threatened buildings is projected to erode by 2100. The bluff area across Johnson Slough is not projected to flood or erode; but this area may have soil stability issues depending on the permafrost in the soil.

Napakiak will need to carefully evaluate their options before selecting a path forward. It should be noted that the projections are just an estimate; the timing of the erosion could be later than projected, or earlier, depending on the actual weather that occurs.

The Village of Napakiak is already facing some climate change impacts to food security and winter travel; fish and game populations appear to be declining and ice fishing is getting particularly dangerous due to a reduction in the ice thickness. Also, winter travel is becoming unreliable due to a reduction in the number of days the tundra is frozen, making it more difficult and expensive to obtain food, fuel, and supplies. These conditions may become worse in the immediate future, before improving. With time, river travel will likely occur year‐round providing a cost‐effective route to supply goods and services. Villagers will likely need to adapt their lifestyles to accommodate projected changes in the timing and availability of foods, along with their methods for harvesting and gathering foods.

Chefornak – Protect in Place. Climate change is likely to affect the livability of the Village of Chefornak with projected flooding and erosion impacting critical infrastructure and warmer, wetter climates influencing traditional lifestyles. Climate changes have already had significant impacts on the Village of Chefornak due to extreme weather events, thawing permafrost, and deceases in Arctic sea ice. Storms accompanied by gale force winds have caused extensive flooding and erosion and impacted the thermal properties of the permafrost, which has further exacerbated the effects. Critical infrastructure has been, and will continue to be, affected which has significantly impacted the livability of the village.

Chefornak is projected to have increased flooding, with 50‐year flood events (ARI 50) of over 7 feet. Erosion is predicted to continue at an accelerated rate with loss of homes and critical infrastructure by 2030, including the Head Start Building, which is contaminated with asbestos, and the access road to the tank farm. The pipes from the farm to the village run along the road and are, therefore, also at risk. By 2070, it is projected that the tank farm will be lost to erosion.

The high-risk areas are near the shoreline and outside of the Basalt rock extension; lands and structures located on the Basalt have higher elevations and are at low erosion and flooding risk.  Protecting-in-place in the low-risk areas is a viable option for Chefornak. Critical infrastructure can be built outside of the flood/erosion risk areas and incorporate designs that will mitigate the projected permafrost thaw risk, and the risks projected from slow onset and extreme future climates. The barge landing, which must be located within the high-risk area, should be designed to withstand future climate impacts. It should be noted that the risk projections presented are just an estimate; the timing and magnitude of the erosion, flooding, and permafrost thaw could vary from that projected depending on the actual weather that occurs.

Villagers are already facing some climate change impacts to food security and winter travel, making it more difficult and expensive to obtain food, fuel, and supplies. Unfortunately, given the projected future climates, these conditions may worsen in the immediate future, before improving. With time, river travel will likely occur year-round providing a cost-effective supply route. Villagers may need to adapt their lifestyles to accommodate projected changes in the timing and availability of foods, as well as their methods for harvesting and gathering foods.

Conclusions: The assessments provided site specific data on the magnitude and timing of projected climate impacts, enabling community members to be proactive in developing resilient communities for future generations based on the specific goals of their community. ​​