When it comes directly to heating up an aircraft, yes.
Currently, anything above the 49th parallel gets quite cold, and it's very expensive and requires a fair bit of jet fuel as well as diesel fuel to heat an aircraft. The number one reason for heating is to make sure the water lines don't freeze and the pipes don't burst. The secondary consideration, which is also very important, is passenger comfort and safety.
Aircraft are almost as efficient as they can currently get, outside of moving over to electric, but in terms of heating up aircraft, we do dramatically reduce their emissions.