== Arable land source == 
 I am looking for a source concerning arable land and surface area breakdown of Earth. I was excited to see this line of the article: 

 The total arable land is 13.31% of the land surface, with 4.71% supporting permanent crops 

 I was, however, disappointed to see that it refers to a page that makes absolutely no mention of arable land… Perhaps the source changed or it was never there, but I think this should be fixed.