Many clues have been revealed as to the state of global warming in Year Zero.
- Baseball in February: The posts on Another Version of the Truth's forum relating to Angry Sniper's attack on Wrigley Field indicate it occurs in early February, 0000. This, and with the play-by-play announcer's comment on "a beautiful spring day" indicate that the Major League Baseball season has been shifted so that playoffs are in spring.
- A message intercepted in The Mailstrom, advertising Green Bay, Wisconson as a Spring Break destination. It mentions that Florida has become sunken (probably due to rising ocean levels), and that the South is "Hotter than a breakfast skillet".1
- Another message intercepted by The Mailstrom, advertising an oppertunity to hunt the last surviving Black Bear.
- A newspaper clipping at the Judson Ogram site states that Hurricane Boaz came in February. Since it begins with B, we can tell that it was already the second hurricane of the year. This would prove that hurricane season is year-long.