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The Hidden, Horrifying Impacts of Climate Change

It's not all hurricanes and floods. Expect sewage in your drinking water.


We've all heard the global-warming horror stories. Rising seas will eventually sink coastal cities from Miami to Los Angeles. Hurricanes and tornadoes will increase in strength, flattening entire towns. And extreme, lasting droughts will cripple large swaths of the western U.S. 

But other consequences of climate change are flying under the radar. They might not be flashy enough for Hollywood disaster flicks, but they're frightening in their own right.

Consider the impact on a city far from the ocean: Chicago. A few weeks ago, flash floods in the Midwest prompted officials in the greater Chicago region to release raw sewage and storm runoff right into Lake Michigan—a popular bathing spot for Chicagoans. And on Wednesday, the Washington Post reported that downpours are causing human waste to back up into homes—and that eggs carried by the sewage are then hatching into maggots and flies.

That's just one example. Here are four more.

Parasites invade the Arctic—and your brain

Warmer temperatures in typically cold regions is causing both rare and common diseases to spread further. Cases of malaria and dengue fever—mostly found in Africa and the Asia-Pacific—are expected to rise as warming temperatures attract mosquitoes, which transmit the diseases, to formerly cold regions. The largest international authority on climate change, the IPCC, said in its 2013 report that “even modest warming may drive large increases in transmission of malaria, if conditions are otherwise suitable.” Certain rare parasites could spread, too. Scientists are still studying the water-borne Naegleria fowleri, known as a brain-eating amoeba, but say its movement farther north could be due to climate change. There were only 34 known cases in the U.S. in the last decade, but it kills nearly 100 percent of the time—including a 9-year-old girl in Kansas last week. Before 2010, half the cases were in southern states, but it’s since been found as far north as Minnesota, Scientific American noted. Other parasites, like the Toxoplasma gondii, carried by animals and known to harm humans with weak immune systems, have moved into even colder areas as far as the Arctic

Insects wipe out forests

The mountain pine beetle, which is as big as a grain of rice, and spruce beetle have damaged more than 42 million acres since 1996. Though invasive insects would still pose a threat without climate change, they especially thrive in mild winter conditions, moving into higher altitudes and exploding in population when otherwise they would die during winter. Drought hasn’t hurt the invasive insects, either, leaving dry trees with weaker defenses. It’s not just the pine beetle: The hemlock woolly adelgid threatens 19 million acres of eastern hemlock forests.

Oceans acidify, killing coral and fish

About a quarter of the increased levels of carbon in the air wind up absorbed into the oceans through the water’s surface, changing the chemical makeup so it becomes more acidic. Even small changes in acidity mean mass extinction for marine life not equipped to adapt. Increasingly acidic oceans are destroying coral reefs and the small sea life eaten by larger fish and whales. High acidity makes it harder for animals like oysters, clams, and scallops to grow their shells. New research suggests fish even lose their ability to smell. Scientists say the oceans have already become 26 percent more acidic since the late nineteenth century.

Feces leaks into your drinking water

When flash flooding hits a community without much warning, it can overwhelm old sewer systems. On direct contact, sewage can cause severe illness and, in rare cases, death; it can also leak into drinking water. The Union of Concerned Scientists warned as much in a report that said more than half of waterborne illness outbreaks follow heavy rainfall. Hurricane Sandy, for example, caused 11 billion gallons of sewage to leak into rivers, canals, and city streets. When there’s unprecedented flooding, other infrastructure is at risk, too. During extreme rainfall in Colorado last year, environmental groups pointed out that open pits of fracking wastewater probably had mixed with floodwater.