I found a little report that MSNBC did in 1999 on the worst natural disasters ever, the good news is this was far from the worst. A retrospective silver lining if you will.
In terms of deaths, the worst natural disaster of the millennium was a Chinese flood that killed 900,000 in 1887. This centurys worst natural disaster was an earthquake in July 1976 that killed 290,000 people in the Tangshan region of northeast China.
There was also an Earthquake in Shanshi China in 1556 that killed 830 000 people; it tops the US Geological Survey list of the Most Destructive Earthquakes on Record in the World.
I couldn't believe that I got all the way through that without mentioning Bangladesh, which is normally a magnet for this kind of thing. So I checked again and a Discovery Channel Website cited a cyclone and resulting floods in 1970 that killed 500 000 people in that miserable little country. This means that MSNBC's claim of the Tungshan quake being the worst natural disaster of the century is about 200 000 deaths shy.
The same page also mentioned that the worst Earthquake in History happened in the Eastern Mediterranean in 1201 and killed 1,100,000 people in Syria and Egypt. And it mentions a drought in China between 1876 and 1879 that killed over nine million, making it the worst drought in recorded history.
If I've missed anything, please leave a comment and straighten me out. The Gentle Rant loves to be corrected. Be as snotty as you like.