The United States has stumbled into a potential military confrontation with Russia over Ukraine - a dangerous predicament that could become a Cuban Missile Crisis in reverse.
The "Black Death" moved across Eurasia, driven by climate events that were and still are frequently occurring.
Justin Doolittle is a freelance writer based on Long Island. He has an M.A. in public policy from Stony Brook University. You can follow him on Twitter @JD1871