Wal-Mart aims to cut plastic-bag waste in its global operations by an average 33 percent over the next five years, the retail behemoth announced Thursday at the annual meeting of the Clinton Global Initiative. And if you ever doubted that Wal-Mart is big, consider this: The move is expected to eliminate some 9 billion plastic bags each year, equating to more than 135 million pounds of trash by 2013. Wal-Mart will give out fewer bags, offer plastic-bag recycling, and encourage customers to use reusable totes (it will offer its own line of reusable bags for 50 cents each). In the words of one exec, the goal is to “encourage consumers to change their behavior, just one bag at a time.” That appears to apply particularly to non-American consumers: The 33 percent average will be attained by cutting bag use 50 percent in international operations and 25 percent in the U.S.