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.