A nuclear Winter, that is. According to a new study published in this month's Science journal, the world is much likelier to end as a result of the aftermath of nuclear bombs being dropped, rather than the direct impact of the bombs themselves. Sound a little strange? Welcome to a new world order: since the Cold War ended, we don't so much have to worry about the massive nuclear arsenals of the U.S. and Russia being unleashed simultaneously. Rather, so-called "regional" nuclear conflicts, between India and Pakistan, say, are much more likely. Since nations like those have smaller weapons -- about 15 megatons each, the size of the Hiroshima bomb -- and not many of them, the study looked at the effect of 100 "small" bombs being dropped in two subtropical nations.

The results were surprising. Atmospheric modeling has improved since studies like these were last conducted, in the 1980s, and it seems now that the extent of damage possible from the dust kicked into the atmosphere by 100 bombs is much greater than previously calculated. "Soot from fires is black and absorbs solar radiation," one of the study's authors told New Scientist. "As it begins to fall it is constantly being heated and lofted." Such particles, they calculate, rise to the upper atmosphere and stay for more than six years. That's long enough -- and dark enough -- to disrupt growing cycles, cause worldwide famine and plunge temperatures below those experienced during the 16th century (AKA Europe's "little ice age"). So just in case you had stopped worrying about nuclear war, we're giving you permission to start again.