While changing requirements are outside of your control, clearly the consequences affect you, however unfairly. It's a skill to predict what might change and which parts of the project could end up being wasted time, and you will develop it with experience. I think being in continuing regular communication with your manager and team members as others are suggesting is also a good idea and partially for indirect reasons, because you might pick up on some clues of what these things outside your control may end up affecting how your performance is perceived.