Yes, you can ripen bananas faster with a few simple tricks. Place the bananas in a brown paper bag and roll the top of the bag closed. The ethylene gas naturally produced by the bananas will be trapped in the bag, which will speed up the ripening process. Adding an apple or a tomato to the bag can also increase the ethylene levels and help ripen the bananas even faster. Another option is to keep the bananas in a warm area, such as near a sunny window or on top of the refrigerator. Warmer temperatures can expedite the ripening process.