[T.B. Yoits]

“Throttling engines back and “gliding” to “be greener” isn’t going to happen either since the amount of throttle needed is dependent on the altitude of the runway and thus the altitude of the plane that’s landing. The higher the altitude, the more power needed just to maintain lift and control.”

False.

False? Try dropping power before flaring at a high elevation airport. It gets real fun real fast. You need that power for lift and control of the aircraft.

On final, when you set your airspeed (lets say to 180 Knots Indicated Air Speed for a commercial jet), your engines are powered up higher if you're at 8,000 feet than if you were at 300 feet.

[steve86]

No, indicated airspeed corrects for all that.

Only if you have to maintain the same glideslope will more thrust be needed. The guideslopes in the ‘green” approach system are adjusted for that. Glideslope is steeper.