Rapid Alaskan Permafrost Melt Could Rupture Trans-Alaska Pipeline

The Trans-Alaska pipeline. Note the supports which are embedded in the permafrost below. Photo: Alaska Region, U.S. Fish and Wildlife Service

The Trans-Alaska pipeline brings an average 1.8 million barrels of oil per day through its 800 miles (1,287 kilometers) of 48-inch (1.22 meters) diameter pipes. It connects drilling sites from Prudhoe Bay to Valdez, Alaska, where the oil is transported by ships and other means.

The pipeline was constructed between 1975 and 1977, after the 1973 oil crisis when Saudi Arabia-led OPEC, the then relatively young Organization of Petroleum Exporting Countries, chose to issue a total embargo on oil shipments to the United States, Canada, the United Kingdom, the Netherlands, and Japan due to their support of Israel. At that time the pipeline seemed like the only way to protect the U.S. from being held hostage in that way ever again.

The pipeline is privately owned by the Alyeska Pipeline Service Company.

Since the pipeline first came online, it has weathered multiple earthquakes with surprisingly little in the way of oil spill accidents or the need for major repairs. That track record is ending now, thanks to global heating because of the climate crisis.

Engineering teams which monitor the pipeline have discovered the continuing rise in Arctic temperatures and down into Alaska are threatening the supports that hold the pipeline above hundreds of miles of permafrost.

As in many other northern regions of the planet, that permafrost is melting now, sometimes at staggering high rates. The melting has already contributed to large carbon, carbon dioxide, and methane releases into the atmosphere in places from Siberia to northern Canada and across to Alaska. It is also now causing shifts in what in the 1970s seemed like the perfect permanent foundation for the supports for the Trans-Alaska pipeline.

As the permafrost gives way and shifts, those structures which keep the pipeline at a flat level above the ground have begun to shift and twist. This has created a phenomenon known as “slope creep” along large sections of the pipeline’s path.

If those structures were to give way and break suddenly, a situation which appears more likely every day according to those who manage the pipeline system, it would both shut off the oil from Prudhoe Bay instantaneously and create an environmental disaster which would be nearly impossible to clean up.

The Alaska Department of Natural Resources, unlike most state and federal agencies who have studied impacts related to the climate crisis, has taken action to address what might happen. It has helped develop and has now approved installing 100 thermosyphons, tubes that act as mini heat pumps to transfer the heat building in the permafrost away from the ground. For a while at least, this could prevent the “slope creep” from growing worse as the Alaskan terrain grows warmer.

One potential problem with these tubes is the very act of installing them will disturb the permafrost and potentially destabilize the supports even more. Further, although this thermosyphon technology has been used before in the state, it has never been used before to stabilize a permafrost base which has already begun to melt.

There is also the issue that this is only a temporary measure, since global heating is going to continue upwards for centuries to come. Even if the thermosyphons achieve their short-term objective of stabilizing the pipeline supports, that will not last long. Within the next five years, the melting will have increased to the point where a more radical solution is needed, assuming the goal remains to keep the pipeline operational.

That calculation is backed up by a recent study published in the journal Nature Climate Change. It notes that an increase of 2 degrees Fahrenheit in air temperatures over Alaska will melt as much as 1.5 million square miles of permafrost. Even the most conservative estimates say that amount of temperature gain will happen in Alaska within the next ten to fifteen years, as the state and the Arctic in general grow warmer at a rate twice as fast as the rest of the planet.

Rerouting the pipeline is not an option either, since an estimated 85% of Alaska’s land mass is covered with a layer of permafrost. There is no other safe place to go.

While the temporary fix of installing the thermosyphons may prevent the immediate rupture of the Trans-Alaska pipeline, there is only one fix which makes sense in the long run. With the oil from Prudhoe Bay only contributing to an ever-increasing glut in oil supply, and with the burning of that oil making the climate crisis ever more dangerous, the pipeline should be shut down. Humanity simply has to stop using fossil fuels.