Alaska and the Fifth National Climate Assessment
Emphasis on Impacts
The US Fifth National Climate Assessment (NCA5) was released November 14, 2023, and like the four previous assessments there is a chapter on Alaska.1 This assessment continues the evolution of the National Climate Assessment from a focus on what is happening (physical science) to why it matters (impacts to people and society). The link to the Alaska chapter is here and I encourage you to bookmark and use this chapter as a ready reference for an overview of why a rapidly changing environment matters to Alaskans.2
Alaska Chapter Headlines
If you’re reading this you already know that Alaska and Arctic climate and environmental change has been ongoing for decades, the changes are obvious and are impacting ecosystems, cultures and societal activities. The NCA5 Alaska Chapter centers the impacts of this change in and around the state, especially in regards to rural Alaska. This is an important shift in emphasis from previous assessments and reflects both the differences in physical environmental changes (see the following section) and disproportionate impacts to rural Alaska due to dramatic differences in economies, infrastructure and population and human capacity compared to urban Alaska.
Straight from the Alaska Chapter, here are the key messages and short summaries. I’ve highlighted some points I find especially important.
Our Health and Healthcare Are at Risk
Health disparities in Alaska, including access to healthcare and health outcomes, are exacerbated by climate change.
Our Communities Are Navigating Compounding Stressors
Climate change amplifies the social and economic challenges facing Alaska communities. Resource shifts, coastal and riverbank erosion, and disproportionate access to services will continue to threaten the physical and social integrity of these communities. Increased adaptation capacity and equitable support have the potential to help rural and urban communities address Alaska’s regionally varied climate-driven threats.
Our Livelihoods Are Vulnerable Without Diversification
Livelihoods, especially those dependent on natural resources, are at risk around Alaska. While advancing climate change has contributed to the collapse of major fisheries and is undermining many existing jobs and ways of life, it may also create some opportunities related to adaptation and response.
Our Built Environment Will Become More Costly
Much of Alaska’s infrastructure was built for a stable climate, and changes in permafrost, ocean conditions, sea ice, air temperature, and precipitation patterns place that infrastructure at risk. Further warming is expected to lead to greater needs and costs for maintenance or replacement of buildings, roads, airports, and other facilities. Planning for further change and greater attention to climate trends and changes in extremes can help improve infrastructure resilience around Alaska.
Our Natural Environment Is Transforming Rapidly
Alaska’s ecosystems are changing rapidly due to climate change. Many of the ecosystem goods and services that Alaskans rely on are expected to be diminished by further change.
Our Security Faces Greater Threats
Rapid climate-driven change in Alaska undermines many of the assumptions of predictability on which community, state, and national security are based. Further change, especially in the marine environment with loss of sea ice, will create new vulnerabilities and requirements for security from multiple perspectives and at multiple scales. Greater capacity for identifying and responding to threats has the potential to help reduce security risks in the Alaska region. [“Security” in this key message is much broader than “military security”—RT]
Our Just and Prosperous Future Starts with Adaptation
Local and regional efforts are underway around Alaska to prepare for and adapt to a changing climate. The breadth of adaptation needed around the state will require substantial investment of financial resources and close coordination among agencies, including Tribal governments. The effectiveness of adaptation planning and activities can be strengthened by addressing intersecting non-climate stressors, prioritizing the needs of the communities and populations experiencing the greatest impacts, building local capacity, and connecting adaptation efforts to economic and workforce development.
One of the themes running through the key messages is the intertwined effects of a changing environment with other aspects of modern but deeply inequitable society that all play a role in Alaskans’ heath and well being. This complexity is nicely illustrated by the figure from Key Message Our Health and Healthcare Are at Risk, reproduced here as figure 1.
How fast is Alaska warming?
Of course, you probably figured I’d get in a little climate science into this post. One question that came up during the initial release webinar is how fast is Alaska warming relative to the global average. Figure 2 plots the global annual average temperature and the Alaska annual average temperature as a departure from the 1951-1980 baseline since 1940. Alaska and global temperature departures start to separate in the 1970s, and while there is far more variability in year-to-year temperatures in Alaska, the faster rate of warming for Alaska Alaska is evident. Annual average temperatures since the early 1970s for Alaska as a whole have increased at more than twice the rate of the global average.
Given the size and geographic complexity of Alaska, it’s not surprising that there are large regional variations in the magnitude of temperature change, which are illustrated in Fig 3. All of Alaska and vicinity has warmed in the past 50 years. The central and western Aleutians and southeast Interior have warmed more slowly than the global average, while thanks to the dramatic loss and thinking of sea ice, the western and central North Slope has warmed at more than four times the global average.
These disprate changes suggest different impacts in different parts of the state, and NCA5 Alaska Chapter provides a needed link to how these changes intersect with society.
Full Disclosure
I was a “technical contributor” to the NCA5 Alaska chapter but had no role in the key message development or text writing. I am very proud of my ACCAP colleagues Adelheid Herrmann, Danielle Meeker and Sarah Trainor who contributed to NCA5 as Alaska chapter authors. I’m grateful to Henry Huntington for leading this multi-year effort and everyone who contributed to bringing this to fruition.
Previous National Climate Assessments were released in 2000, 2009, 2014 and 2018
As of this writing (November 23, 2023) a pdf of the full chapter was not yet available.