Top 50 Emitters Threaten Global Climate Effort, CDP Says Carbon emissions from the 50 top emitters in the FT Global 500, including ArcelorMittal (MT), RWE AG, Wal-Mart Stores Inc. (WMT) and Exxon Mobil Corp., rose 1.7 percent in the four reporting years from 2009 to 2.54 billion metric tons in 2013, the report shows. Those 50 pump out 75 percent of all emissions reported by the Global 500. WalMartization Got Hemp? Hemplastic or Fossil Fools Crud