The permafrost is melting due to increases in the Earth’s temperature, which most scientists attribute to climate change. Seasonally frozen ground thaws and refreezes each year, covering about 58 percent of the land in the Northern Hemisphere surrounding the Arctic Circle.
Massive regions of permafrost exist in the Tibetan Plateau, the Canadian Arctic, Siberia and the state of Alaska, as well as parts of Greenland. The northern areas of Alaska contain continuous permafrost, up to 80 percent of the state’s lands, while parts of Alaska’s interior experience sporadic freezing of the ground. Even large parts of the continental United States experience seasonally frozen ground each year.
What Is Permafrost?
Beneath the surface of the ground in areas of the Northern Hemisphere near the Arctic Circle, a thick layer of soil stays permanently frozen throughout the year; this is called permafrost in areas where the ground stays frozen for a minimum of two years in a row. Right now, permafrost covers about 9 million square miles of land in the Northern Hemisphere. The depth at which the ground freezes depends on the weather conditions each winter season. Nearly 80 percent of the state of Alaska has permafrost beneath the surface of the ground.
Permafrost, Arctic Ocean and Climate Change
Scientists posit that 55 million years ago during the Paleocene-Eocene Thermal Maximum, the Earth suddenly warmed by 5 degrees Celsius (a degree change of about 9 degrees Fahrenheit). They now figure it occurred because of the sudden release of massive amounts of greenhouse gases, or carbon dioxide and methane, stored in the permanently frozen grounds of the Earth by dead and rotted plant life.
Once the permafrost melted 55 million years ago, carbon dioxide and methane were released into the atmosphere, creating the greenhouse effect that trapped the sun’s rays in the atmosphere and led to higher global temperatures. Areas of the sea bed in the Arctic and Antarctic are also permanently frozen.
Melting Permafrost and Erosion
Melting permafrost leads to soil erosion along coastal areas and in other waterways, lakes and rivers. For Alaskans, houses, roads, buildings and pipelines are under threat when the ground beneath begins to thaw. What once offered a strong foundation on which to build has now become soft and unstable.
Along coastal regions, the mushy, soft soil left in its wake after thawing slides into the sea, threatening the homes, the communities and livelihood of many of Alaska’s native inhabitants who live on river and ocean shorelines. Permafrost thawing causes damage to landing strips for planes, highways, railroads and other infrastructure.
Permafrost and the Carbon Reservoir
Methane is a naturally occurring greenhouse gas that forms as carbon-based plant and animal life decay. Methane trapped in the soil releases as the permafrost thaws and decomposes. Scientists estimate that the frozen north contains at minimum 1,672 Petagrams of stored carbon, with one Petagram equating to 1 billion metric tons.
As this carbon reservoir thaws, it adds to and complicates the human-induced global warming fed by the burning of fossil fuels and the continued release of greenhouses gases into the atmosphere. As the permafrost melts and the gases trapped within release and contribute to this effect, global warming speeds up.
Permafrost and Zombie Diseases
In the summer of 2016, after a heatwave in Siberia thawed the carcasses of dead reindeer killed by anthrax, several people became infected with the disease. As the carcasses thawed, more anthrax spores did as well and spread across the tundra, sickening several people and killing a 12-year old boy. People who died of smallpox and even the flu strain of 1918, which killed more than 50 million people, remain buried in areas of the frozen tundra. If their remains thaw, some people fear the diseases the could reoccur, like with the anthrax breakout, though scientists say anthrax stays in the soil all around the globe, and outbreaks occur because of it all the time.
While some diseases can arise from the frozen tundra, many don’t as they cannot survive being frozen, even after scientists have tried to revive them in a lab, reported National Public Radio in January 2018. Of the diseases that have reoccurred, most are successfully treated, as in the case of one researcher who contracted seal finger, a seal-hunter's bacterial disease that he was exposed to when working with thawing seal carcasses.
Multiple agencies around the globe currently monitor the thawing of the permafrost in the frozen North. In 2005, the Permafrost/Active Layer Monitoring Program began in Alaska, which added monitoring stations across the state in mostly remote locations. The stations collect data that includes temperature changes and the status of the active permafrost layers.
Participants in the study include national parks and many of the schools across the state of Alaska. Once someone collects the data, another person submits the data to multiple science databases, including the National Snow and Ice Data Center located in Boulder, Colorado, where scientists study the changes happening and distribute the results to others who hope to come up with solutions to the increasing problem.
- National Snow and Ice Data Center: Where Is Frozen Ground?
- Science Magazine: Did Melting Antarctic Permafrost Drive Ancient Global Warming?
- University of Colorado at Boulder: Natural Gas
- Yale Environment 360: Melting Arctic Ocean Raises Threat of "Methane Time Bomb"
- USA Today: Alaska Sinks as Climate Change Thaws Permafrost
- National Park Service: Permafrost/Active Layer Monitoring Program: Involving Remote Villages in Permafrost Drilling for Operational and Scientific Applications in Alaska
- NASA Earth Observatory: Effects of Changing the Carbon Cycle
- Engineering Toolbox: Temperature
- University of Hawai'i at Manoa: Carbon Cycling
About the Author
As a journalist and editor for several years, Laurie Brenner has covered many topics in her writings, but science is one of her first loves. Her stint as Manager of the California State Mining and Mineral Museum in California's gold country served to deepen her interest in science which she now fulfills by writing for online science websites. Brenner is also a published sci-fi author. She graduated from San Diego's Coleman College in 1972.