Humanity Has Turned Land Itself Into a Menace

Buildings in Russia are crumbling like they’re made of Lego bricks. Alaska spends millions of dollars each year repairing roads that are dipping and wrinkling. In Canada, Iqaluit Airport’s runway is sinking, when pilots would really prefer it not.

You can’t blame engineers for building on top of permafrost, the frozen land of the far north and high altitudes—in some Russian cities, up to 80 percent of buildings sit on this ground. The substrate is supposed to stay frozen; it’s right in the name. But land in the Arctic, and beyond, is in revolt. As the Arctic warms four times as fast as the rest of the planet, permafrost is thawing at an alarming rate, dragging down whatever’s at the surface or buckling anything that’s buried—roads, railways, pipelines, sewers, electrical transmission lines.

“Permafrost regions, they actually are not vast empty spaces where polar bears live,” says George Washington University climate scientist Dmitry Streletskiy, coauthor of a review paper on permafrost that was published last week in the journal Nature Reviews Earth and Environment. “There are a lot of people, industries, settlements, developed infrastructure, and those regions are very active economically.” Permafrost thaw threatens hundreds of Arctic villages and cities, and could put up to 70 percent of circumpolar infrastructure at high risk by mid-century, his team writes, costing billions to repair roads, bolster structures, and ensure that trains don’t derail on warped tracks.

Permafrost is a mixture of dirt, sand, or gravel frozen in a matrix of ice. Because solid water takes up more space than liquid water, when permafrost thaws, the land shrinks. The higher its ice content was, the greater the dip. If this sinking were happening uniformly across a landscape, it might not be such a big deal, as the infrastructure would also sink uniformly. But if the ground thaws at one end of a building but not the other, the differential can snap the foundation. It’s a particularly bad problem in big Soviet-era cities full of large apartment buildings that put a lot of weight on the permafrost: By 2012, some 40 percent of buildings in the Russian city of Vorkuta had already suffered this deformation, and in some indigenous towns it’s more like 100 percent.

Roads and railways—known as linear infrastructure—are even more vulnerable because they stretch across the landscape, and therefore have plenty of opportunity to sink at different rates. “You don't want part of a pipeline to go down and another [part] stay in the same place,” says Streletskiy. Roads face an additional challenge; they’re out in the open where the sun can heat the underlying permafrost. (Buildings at least provide a bit of shade to keep the ground cool.)

But even if permafrost doesn’t totally thaw, warming may compromise its structural integrity, and that of whatever’s on top of it. “If you take pizza out of the freezer, it is frozen solid,” says Streletskiy by way of analogy. “You put it on a table and with time it becomes kind of softer and softer. It is still frozen, but you already know the mechanical properties are changing.”

Thawing permafrost also exacts an incalculable cost on the climate: It stores half of the organic carbon in the world’s soils. As it thaws, microbes start to chew on that organic material and spew greenhouse gases, which further heat the planet. In some parts of the Arctic, permafrost is thawing so quickly that it’s gouging craters in the ground, where standing water releases methane, a particularly potent greenhouse gas.

Permafrost thaw joins peat fires and land subsidence—when soil collapses after losing groundwater—in a triad of understudied yet hugely important geological menaces of humanity’s own making. Peat is made of thousands of years’ worth of plant material that have accumulated, layer after layer. It’s not frozen, but wet, which preserves the organic matter. Yet as the climate warms, it’s been drying out across whole landscapes, creating a carbon-rich fuel that can burn with one lightning strike. “Nature doesn't want peat to be flammable,” says Guillermo Rein, who studies peat fires at Imperial College London. Unlike typical Californian or Australian wildfires that race through vegetation, this kind of fire smolders through the ground. “They are the largest fires on Earth, but also the slowest fires on Earth. Like, literally a baby can outrun them,” he continues.

That, however, does not make them harmless. The things are darn near impossible to extinguish: In the Arctic, they’ll actually smolder underground through the winter, even when snow falls, then pop up again as “zombie fires” in the spring. But unlike permafrost thaw, this kind of climate-related threat is not confined to high altitudes and areas near the pole. In 2008, officials flooded a peat fire in North Carolina with 7.5 billion liters of water from nearby lakes—it took seven months to finally drown the blaze.

In its smoke, a peat fire also releases clouds of carbon that used to be locked underground. “Every single gram of peat that burns is immediately, instantaneously a net emission, because it takes hundreds to thousands of years to create peat again,” says Rein. “If you burn a tree or a branch or grass, it is not yet a net emission because you can still grow back the biomass.” That is, new plants quickly sequester carbon from the atmosphere as they take hold. But it takes centuries for peat to form—if it can even form again. The environment may no longer be wet enough to preserve plant material as peat.

Current climate models just don’t account for the role of huge carbon-belching peat fires, like Indonesia’s enormous blaze in 2015. Neither do tallies of nation-level emissions. But if you were to count peat emissions, “that makes Indonesia to be one of the top carbon emissions countries in the world,” says Rein. “Not because of their power plants, but because they have absolutely massive peat fires.”

Indonesia is also grappling with the final menace in the geological triad: land subsidence. As the capital of Jakarta has grown, the residents have drawn too much from the underlying aquifer. Now the aquifer is collapsing like an empty bottle, and parts of the city are sinking almost a foot a year. Mexico City, which is similarly overexploiting local aquifers—and is also built on top of compacting sediment—is sinking up to 20 inches a year in spots, and could see a drop of 65 feet in the next 150 years. “Even if you stopped the pumping, the process would not stop for decades,” says Arizona State University geophysicist Manoochehr Shirzaei, who studies land subsidence. “The damage is done.”

To make matters worse, in some parts of the world, more intense droughts mean there’s less rain falling to replenish aquifers—and that human demand for groundwater is higher than ever.

Like permafrost thaw, the damage in Jakarta and Mexico City is worse where infrastructure spans land that’s sinking at different rates. But Jakarta’s situation is even more dire because it’s on the coast, so it’s both sinking and getting flooded by rising seas, to the point where the Indonesian government is now considering moving the capital to a different city. The San Francisco Bay Area has the same problem of subsidence paired with sea level rise. Subsidence can also lead to seawater intruding into groundwater along coastlines. This kills trees, which drives additional erosion of the soil, since the roots rot away.

What this all adds up to is that climate change is making the ground beneath us more perilous, through the interlacing processes that drive thawing, slumping, fire, and carbon release. It’s an enormous risk to infrastructure—and we’re only building more. “As the population is growing, people are getting used to a more luxurious style of living—more people want to fly, more people want to drive cars—so we need more highways or airports,” says Shirzaei. “And this is the accumulation of assets where the hazard is exacerbated.”

Humanity Has Turned Land Itself Into a Menace

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