(UPDATED) Several videos have cropped up on YouTube documenting a "weird phenomenon" variously described as "burning snow," "fake snow," "chemical snow," and "snow that won't melt." The videos show people holding cigarette lighters and blowtorches up to handfuls of snow and remarking on how the latter seemingly blackens and "burns like plastic" instead of melting, giving off a "chemical odor."
As is the fashion these days, folks are resorting to conspiracy theories in lieu of science to explain the phenomenon, the result being one big Internet freak-out over supposed government-backed weather manipulation ("geo-engineering"), chemtrail fallout, nanobot invasions, and HAARP attacks (I even found one article using the term "false flag").
On the other hand, there's plain old, ordinary physics. If you take a blowtorch to snow (which is more air than water in the first place), some of the frozen H2O is simply going to evaporate. Ditto if you use a lighter, albeit on a smaller scale. What doesn't immediately evaporate has to melt, but may not appear to be melting initially because, explains Metabunk.org founder Mick West, "the very loose fluffy structure of the snow wicks away the water, turning dry snow into wet snow, and eventually turning the snow into slush." In cases where the snow seems to blacken and burn, the effect is caused by soot from the lighter. "The smell," West adds, "is fumes from the lighter (also from incomplete combustion) and/or people briefly burning nearby objects like gloves" (detailed explanation continues).
Hate to spoil the fun, but Occam's Razor wins the day.
Read more about it (updated):
• Debunked: Fake Snow, Burning Snow - Mick West, Metabunk.org
• It Won't Melt? Why This Week's Snow Was Different - WDBJ-TV News
• Internet Panics Over "Geo-Engineered, Poison" Snow, So We Test It Out - WTVR-TV News
• Meteorologists Debunk the Viral 'IS THIS SNOW?' Video - Accuweather.com
• Conspiracy Debunked: Atlanta Snow Doesn't Melt - Phil Plait, Salon.com