Criss-crossing the globe like scratches on a mirror, our energy sector has erected enormous structures for transporting fossil fuels. There are more than 250,000 miles of oil pipelines across the world, according to the nonprofit environmental group Global Energy Monitor, and that isn't even counting the nearly 18,000 miles of natural gas pipelines.
With so many potential points for failure, these pipes tend to leak also. Like, a lot. In the U.S., 1.8 million gallons of oil were accidentally spilled in 2020, while a report issued earlier this summer by the nonprofit Public Interest Research Groups found that a methane gas pipeline incident occurs somewhere in the U.S. approximately every 40 hours. They report that between 2010 and 2021, more than 300 of these leaks resulted in explosions and fires that killed 122 and injured over 600.
"The frequency of oil spills in general has increased in the last decades, due to increased international transportation of cargo and consumption."
Even before they're burned, fossil fuels can be very toxic. Last year, when a pipeline leak slicked 130,000 gallons of oil on Huntington Beach, California, it smeared critical marsh and wetland habitats, killing fish and birds. In situations like these, the sticky, black liquid can suffocate whales and dolphins, who can't surface to breathe, while birds can become unable to fly and drown. Toxic chemicals within oil can negatively alter animal health. Spills can also disrupt food chains, tainting sensitive ecosystems like wetlands and mangroves.
This autumn has been big for oil leaks, and not in a good way. Just recently, the Keystone Pipeline ruptured due to an unknown cause, gushing nearly 600,000 gallons of crude oil into a creek in Washington County, Kansas. The pipeline, operated by TC Energy Corporation, squiggles for 2,687 miles all the way from northwest Alberta, Canada to the Gulf of Mexico. It is one of many arteries that deliver that critical fossil fuel so many Americans are dependent on. But that dependency comes with a price. When Keystone was first built, many experts warned it was "essentially guaranteed" to leak.
And leak it has. Less than a year after it first began shipping oil, Keystone spilled about 500 oil barrels (21,000 gallons) in North Dakota due to a failed fitting. Officials say the most recent discharge is the largest leak in Keystone's history, and the largest crude oil spill in the U.S. in nearly a decade, but it almost certainly won't be the last.
Because methane is colorless, or invisible to our eyes, such images may not quite capture the seriousness of the situation.
Images of the disaster depicted a beige hillside marred by black goop threading itself into the waterway. But not all pipeline leaks appear so dramatic, nor are they always accidents.
In late September, two natural gas pipelines that run through the Baltic Sea, Nord Stream 1 and 2, were attacked. A series of detonations punched four holes in the underwater pipelines on Sept 26th, releasing so much gas it may constitute the single largest release of methane in human history, to say nothing of exacerbating Europe's ongoing energy crisis.
However, photographs of the incident depict a few bubbles in the ocean, resembling a frothing jacuzzi tub jet. Because methane is colorless, or invisible to our eyes, such images may not quite capture the seriousness of the situation. Methane is an extremely potent greenhouse gas, about 25 times more efficient at trapping heat than carbon dioxide. Nonetheless, some climate experts say that even this massive loss pales in comparison to how much methane the oil and gas industry releases on a daily basis.
"This is a wee bubble in the ocean compared to the huge amounts of so-called fugitive methane that are emitted every day around the world due to things like fracking, coal mining and oil extraction," Dave Reay, executive director of the Edinburgh Climate Change Institute, told Politico in September. It seems unlikely to damage the local environment much either, at least in the long-term. It's not clear if or when the pipelines will be repaired.
While humans have gotten much better at preventing and cleaning up these oil spills and pipeline leaks, they still have serious, widespread impacts on our environment. In some cases, how destructive these impacts can be is a black box. A 2020 study in the journal Environmental Science and Pollution Research analyzed 1702 oil spills between 1970 and 2018, but only 312 (18 percent) reported impacts to wildlife.
The study noted that 71 percent of these spills come from marine vessels. But while most people may assume that only means petroleum tankers, the giant type of ship that was implicated in the 1989 Exxon Valdez oil spill, the bigger problem is actually commercial vehicles, like cargo ships, fishing vessels and even cruise ships. In fact, oil spills from tankers has dropped significantly over the last five decades, but that still hasn't offset the general trend: oil spills are on the rise.
"The frequency of oil spills in general has increased in the last decades, due to increased international transportation of cargo and consumption," the authors wrote. "When all shipping spills are considered, shipping is responsible for significantly greater numbers of spills than all other sources combined. … Remembering that a spill of any size or oil type can significantly affect wildlife, and with the numbers of oil spills reported increasing, there still remains significant concern for wildlife impacts from acute oil spills."
Then, of course, comes the cleanup. The Nord Stream pipelines have stopped leaking at this point, but some people suggested burning it off to prevent it from entering the atmosphere. This might have worked, just like flares at garbage dumps, for example, though some research suggests this isn't actually efficient. Or it could have created a giant fireball. So this idea was scrapped.
Crude oil cleanup is much more difficult. The Keystone leak, for example, also spread bitumen, better known as asphalt, which sinks in water, making it harder to clean. Other forms of petroleum will float on the surface of water, creating a slick just a few millimeters thick. As this spreads out, it becomes more difficult to contain, so a lot of cleanup efforts are based on how quickly workers move to stop it. If an oil spill is detected in time, cleanup crews can skim it from the surface and use special sponges to soak up the fuel.
Other strategies include using dispersants, a special class of chemicals that can break down the oil into tiny droplets and spread it through the water more easily. But while mechanical approaches like skimmers are generally preferred to dumping additional chemicals in the water, these tactics often miss a lot of oil.
"Under ideal (rather than normal) circumstances, skimmers can recover—at best—only around 40 percent of an oil spill," Doug Helton, NOAA's Office of Response and Restoration Incident Operations Coordinator, wrote in 2015. "During the Deepwater Horizon oil spill response, skimmers only managed to recover approximately 3 percent of the oil released."
Ultimately, the best way to clean up an oil spill is to prevent it from ever happening. The more quickly we move away from using fossil fuels for energy, the better it is for all life on Earth, not just humans.
