250 million years ago was not a fun time to live on earth. Studies now suggest that around this time, volcanic eruptions sparked coal fires that may have led to the extinction of over 90 percent of marine species.
The end of the Permian period culminated in a mass extinction, know as the "Great Dying." Researchers had speculated that volcanism contributed to this, and now there is evidence to accompany the theory. According to Discovery News, researchers reported in Nature Geoscience that they found charred particles in the Arctic. The particles may be coal fly ash, created from burnt coal.
Stephen Grasby, the lead author, and his colleagues believe that huge volcanic eruptions east of Siberia could have set coal seams on fire. This would have sent huge amounts of highly toxic fly ash into the atmosphere. After dispersal, the ash would have settled in the water, limiting light penetration. The ash would have created poisonous conditions, thus supporting the theory that coal ash contributed to mass species extinction.
As further evidence of this theory, it appears that a large amount of char was deposited right before the mass extinction, which could have come from the combustion of coal. According to Gransby, "It's the first literal smoking gun to show that coal combustion was occurring."
Fast-forward 250 million years. Today, coal-fired power plants scrub the toxic fly ash from their emissions. But concern has recently been raised over the dangers of coal ash following a coal ash spill in Tennessee, and the sickening of Pennsylvania residents living near a dump site. When pressed two years ago, Homeland Security wouldn't disclose the location of coal ash dump sites as a matter of national security -- the toxic sites were considered too high a hazard.