10 Environmental Disasters That Humans Have Caused

When you hear the word "disaster," you likely think of powerful events outside human control. Hurricanes, earthquakes, and wildfires are a few examples of unavoidable natural disasters. But nature isn't always to blame. Throughout history, humans have caused some of the most devastating environmental events.

From air pollution to oil spills, human-caused disasters can easily become unmanageable. Sometimes, these accidents cause irreparable damage to Earth and its organisms. So, it's in our best interest to learn from the worst of them.

Here are 10 environmental disasters throughout United States history that originated through human fault.

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The Gulf of Mexico Dead Zone

Satellite view of clouds of sediment in the Gulf of Mexico at the U.S. border — Jeff Schmaltz / Wikimedia Commons / Public Domain

In 1985, scientists began mapping a dead zone in the Gulf of Mexico. A "dead zone" is a hypoxic zone with low oxygen and nutrient levels that's inhospitable to most marine life. The Gulf of Mexico dead zone starts in the Mississippi river and it reappears each summer.

For years, humans have polluted the Mississippi River with pesticides, industrial waste, and toxic chemicals. As the river drains into the Gulf, it dumps excess nutrients including nitrogen and phosphorous into the water and causes algal blooms. These blooms create a hypoxic zone in the Gulf as they decay and take oxygen with them.

Scientists measure the dead zone in the Gulf of Mexico each year to monitor its growth. According to the National Oceanic and Atmospheric Administration, the disaster area measured 6,334 square miles—or four million acres—in 2021.

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The Great Pacific Garbage Patch

Map of four ocean currents that make up Great Pacific Garbage Patch and convergence zones where litter accumulates — NOAA / Wikimedia Commons / Public Domain

The Great Pacific Garbage Patch is an environmental disaster caused by human waste. This mass of marine debris located in the North Pacific Ocean is made of barely visible pieces of plastic brought together by the North Pacific Gyre (NPG). The NPG is a vortex caused by four ocean currents—California, North Equatorial, Kuroshio, and North Pacific—that converge and send water and debris clockwise. This creates a "patch" of garbage and microplastics that get caught in the currents.

The size of the Great Pacific Garbage Patch is impossible to estimate, but it's just one of many places where pollution collects in the ocean.

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The Dust Bowl

Dust cloud fills the sky and truck drives on dirt road away from it — PhotoQuest / Getty Images

Beginning in 1930, dust overtook the Great Plains of the United States in a partially human-caused disaster that lasted a decade: the Dust Bowl. During that time, much of this region's land had been over-farmed and most farmers hadn't been practicing soil conservation. As a result, the earth was dry and barren, and severe drought only made matters worse.

These factors sparked the Dust Bowl, an event that saw nineteen U.S. states covered in dust. Topsoil was picked up by strong winds, creating a heavy dust storm that spanned 10 million acres and destroyed farms and buildings. When the drought ended in 1940 and the dust settled, 400,000 people had migrated from their homes.

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Three Mile Island Accident

Aerial view of Three Mile Island nuclear power plant with smoke billowing out of stacks — Dobresum / Getty Images

One of the most significant accidents in the history of American nuclear power took place on March 28, 1979. The disaster happened at Three Mile Island Nuclear Generating Station near Harrisburg, Pennsylvania.

First, a reactor at the plant failed and shut down automatically. Then, a relief valve in the pressurizer, designed to keep the core cool, got stuck in an open position. This caused the system to lose coolant and the reactor's core to partially melt. The unit was damaged beyond repair and released radioactive material into the environment. Responders removed about 110 tons of damaged uranium fuel from the facility. According to the World Nuclear Association, the damage took 12 years to clean up and cost $973 million.

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Love Canal Disaster

Aerial view of abandoned houses and buildings in Love Canal neighborhood — Bettmann / Getty Images

In the late 1970s, Love Canal became the site of an environmental disaster decades in the making. In the 1800s, William T. Love decided to build a canal in the New York neighborhood of Niagara Falls. He started digging but abandoned the project several years later. In 1942, Hooker Chemical Company began using the site as an industrial landfill. It dumped approximately 21,000 tons of toxic chemicals and compounds into the canal before selling the land for development.

After heavy rain in the 1970s, drums of chemicals washed up from the landfill. These contaminated the area with toxic substances and forced 239 families closest to the landfill to relocate. Officials detected 421 different chemicals in surrounding homes, water, and land.

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Tennessee Valley Authority Coal Ash Spill

Rocky landscape covered with grey slurry of coal ash — Brian Stansberry / Wikimedia Commons / CC BY 3.0

On December 22, 2008, the walls of a dam in Kingston, Tennessee, crumbled, spilling 5.4 million cubic yards of coal ash into Swan Pond Embayment. The wave of ash contained arsenic, selenium, lead, and various radioactive materials. As it spread, it contaminated more than 300 acres of land and spilled into the Emory River. Removing the ash from the Emory River and the surrounding area took about six years.

Researchers still don't know the full impact of this disaster on aquatic and terrestrial ecosystems. What they do know is that this spill destroyed many miles of shoreline and acres of native vegetation.

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Exxon Valdez Oil Spill

Firefighters spray water from firehoses to clean up oil from shorelines — Jean-Louis Atlan / Getty Images

In 1989, supertanker Exxon Valdez hit Bligh Reef in Prince William Sound, Alaska. Eleven cargo tanks ruptured on impact and dumped 11 million gallons of crude oil across 1,300 miles of Alaskan shoreline. Two hundred and fifty thousand seabirds, 2,800 sea otters, and hundreds of other birds and marine mammals died of the contamination.

Responders were ill-prepared for a spill of this magnitude. They attempted to remove the oil using burning, chemical dispersants, and skimmers, focusing on high-risk areas first, but clean-up projects weren't completely successful. A 2015 survey found that as much as 0.6% of the oil from the spill still lingers in Prince William Sound.

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The BP Deepwater Horizon Oil Spill

Aerial view of a lone boat in the Gulf of Mexico with oil visible on water's surface — Kris Krug / Wikimedia Commons / CC BY-SA 2.0

Roughly 20 years after the Exxon Valdez oil spill, the largest accidental marine oil spill in history occurred in the U.S. Gulf of Mexico. This disaster took place in April 2010 when an oil well on BP's Deepwater Horizon rig exploded. The Deepwater Horizon oil spill claimed 11 lives and leaked 134 million gallons of crude oil into the Gulf. The spill harmed or killed thousands of marine species including sea turtles, whales, dolphins, birds, and fish. Oil flowed into the Gulf for 87 days before responders successfully capped the well in July 2010, and as of 2021, cleanup efforts are still ongoing.

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2017 California Wildfires

Raging fire overtaking barn sends dark smoke into the grey sky as the building collapses — Justin Sullivan / Getty Images

Global warming is an ongoing environmental disaster. Human activities that may contribute to global warming include fossil fuel burning, deforestation, and livestock farming, all of which have steadily increased the concentration of greenhouse gases in the atmosphere and raised the planet's overall temperature. Many wildfires are caused in part by global warming.

Beginning in October 2017, northern California experienced one of the most deadly and destructive wildfire seasons in history. More than 170 fires were identified and at least 12 were caused by PG&E electric power lines, which caught fire after failing or coming into contact with trees. Higher temperatures associated with global warming and drought created ideal burn conditions and the fires scorched an estimated 245,000 acres of land. The 2017 California wildfires took the lives of at least 47 firefighters and civilians and destroyed thousands of homes and businesses.

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Flint Water Crisis

Greenish brown river in front of city with large buildings and grey sky — Sarah Rice / Getty Images

The Flint Water Crisis was a public health emergency and environmental disaster that began on April 25, 2014. On this day, Flint, Michigan, switched to using the Flint River as its main water source. The pipeline was not tested for toxins or treated for corrosion before becoming operational, and it started leaking contaminants into the city's drinking water. Approximately 140,000 residents were exposed to lead and other toxins such as trihalomethane, with lead levels above 15 ppb detected.

On October 1, 2015, the city issued an advisory that the water wasn't safe to drink, but the pipes weren't fixed. Many residents had no choice but to continue using the contaminated water, which also leached into the ground and polluted nearby lakes, rivers, and streams. This crisis is ongoing. As of 2021, some residents continue to suffer adverse health effects caused by lead poisoning and some still don't have access to clean water.