Things that can destroy Earth with M

• Mars

  If Mars hit Earth, the impact could be apocalyptic.

• Melting ice caps

  Runaway ice melt can trigger extreme climate collapse

• Mobs
• Methane gas

  Potent greenhouse gas; massive release could overheat planet

• Mass extinction

  Mass extinction wipes out most life globally

• Marsupials

The words in the list Things that can destroy Earth with M come from players of the word game City, Country, River.