What can you do to lose belly fat in one month?

Spot fat loss does: not occur naturally. By losing weight in general some will probably be abdominal fat. But, we don't get to choose what area of body fat is lost from. Eat healthy & be physically active. Calories burned must > those consumed. Tighten ab's: crunches, reverse crunches, exercise ball crunches, pelvic thrusts, lying leg raises, side bridge & “bicycling” exercise on back. Do regular aerobic exercise.

Maybe not in 1 month: Exercise a lot (cardio) and cut down on carbs, including alcoholic beverages, although loosing it all in a month is a little bit too ambitious.