 Ice cover across Alaska in 2008. Source: University of Alaska Permafrost Laboratory. Climate changes and the local environment: Alaska is warming more than twice as quickly as the contiguous United States. Over the past 60 years, average annual temperatures in Alaska have increased by about 3°F. Winter warming has been even more extreme, with average seasonal temperatures rising by 6°F. Climate projections based on continuing high greenhouse gas emissions - known as "high emissions scenarios" - predict that average winter temperatures in towns across North Slope Borough in northern Alaska will rise by as much as 25°F in the coming century. By 2050, average annual temperatures across Alaska are expected to increase by 2 to 4°F. As Alaska continues to warm, melting sea ice and coastal erosion represent the two most pressing threats to North Slope Borough. Permafrost is a thick layer of soil, usually a foot or so down from the surface, that remains frozen year-round. Permafrost covers over 80% of Alaska, but that number is shrinking as rising temperatures cause permafrost to melt. When permafrost melts, the ground above it collapses, and methane enters the atmosphere. Methane is a potent greenhouse gas, and although it does not stay in the atmosphere for long when compared to carbon dioxide, it can cause profound regional warming. Thus because melting permafrost also increases atmospheric methane, rising temperatures will provoke even more warming and melting. Increasing temperatures will also melt sea ice on the coasts of Alaska. Models that match historical trends predict that, by 2030, the entire Arctic could be ice-free in the summer. Loss of sea ice is dangerous for ecosystems in North Slope Borough. In the colder past, sea ice acted as a natural barrier to storms and waves. However, as the sea ice melts and recedes from the coastline, wind and water erosion is projected to increase accordingly, especially during big storms. Permafrost also once protected the North Slope Borough coasts from erosion, but it may not for much longer.  Average annual temperatures will increase across Alaska under all emissions scenarios. Warming will be especially rapid in Northern Alaska, including North Slope Borough. Source :U.S. Global Change Research Program. How we know: These predictions are largely based on two easy-to-use tools that are freely accessible online: the National Aeronautics and Space Administration’s (NASA) GISS Surface Temperature Analysis and the National Snow and Ice Data Center’s Arctic Sea Ice News and Analysis (NSIDC). The GISS Surface Temperature Analysis tool uses maps to show global temperature anomalies, comparing current temperatures to temperatures in the 1951-1980 period. Mean temperatures are averaged over a specific time period and interval, and the analysis is updated monthly. Data is compiled from the National Oceanic and Atmospheric Administration’s databases and satellites. The Arctic Sea Ice News and Analysis tool provides updates and scientific analysis on the conditions of Arctic sea ice. The website publishes graphs and animated visuals documenting the extent, depth, and concentration of sea ice. The tool is run by National Snow and Ice Data Center scientists, along with support from NASA. Human consequences: Future climate change will likely have devastating consequences for North Slope Borough and its residents. The imminent reality of a seasonally ice-free Arctic may sound like a desirable outcome at first, seeing that some economic opportunities such as faster shipping routes, oil and gas exploration, and tourism may become available. However, coastal villages, which represent many of the residences in North Slope Borough, will face one of two unfortunate realities as erosion threatens homes. At best, residents will be forced to relocate inland, and at worst, homes and even lives will be lost to the sea. More than 30 villages in North Slope Borough have already been identified for relocation. Indigenous lives are especially threatened as climate change continues in the coming century. Alaskan Iñupiat make up fifty-two percent of all residents in North Slope Borough, according to a 2016 census. Many rely on a subsistence diet and are therefore relatively vulnerable to sudden changes in their surrounding ecosystems. Whales and seals, which are hunted out on the sea ice, constitute the majority of the protein in local Iñupiat diets. With the sea ice retreating, the accessible supplies of fish, game, and whales will decline, and Iñupiat hunters will have to brave dangerously thin ice in hopes of catching food. Thawing permafrost may also undermine human health and economic growth in North Slope Borough. These problems will include a loss of clean water, saltwater intrusion, and the expansion of diseases northward into the warming climate. Many villages, especially those of lower income, dig holes into the permafrost and use these to dispose of and contain sewage; however, as the permafrost thaws, the sewage will leak out, resulting in contamination and the spread of disease. Thawing permafrost will also contribute to increasing pollutant exposure to residents, as the soil contains a significant amount of mercury and carbon dioxide. Additionally, thawing permafrost is projected to add up to $6.1 billion in maintenance costs, as the uneven sinking of the ground will disrupt existing infrastructure. Unfortunately, many of these events will occur even if warming is slowed by curbing emissions. Combating these changes will require both adaptation and resilience in North Slope Borough and beyond. Further reading: Alaska Regional Climate Projections. Scenarios Network for Alaska Planning. Alaska. U.S. Global Change Research Program Article author: Georgia Brainard, Georgetown University
Article editor: Dr. Dagomar Degroot, Georgetown University
10 Comments
|
RSS Feed