A section of the Trans-Alaska Pipeline as it runs north from Valdez along the Richardson Highway. Alaska's traditional and modern infrastructure both depend on the permafrost, or frozen soil, staying frozen. The Trans-Alaska Pipeline runs above ground or in insulated ditches to keep the heat of the oil it transports from thawing the permafrost it rests on. Scientists are already measuring significant thawing in Alaska's permafrost, which suggests potentially disastrous consequences for the pipeline and many other parts of Alaska's built and natural environment.
