You don't genetically engineer apple trees for that. You just cut them at the desired height, and you bind the branches along steel struts or other structures. That's something farmers do since at least 2500 years.
So that's how I know that the glaciers I know of are receding: By actually going there and looking at them.
Trying to be happy is like trying to build a machine for which the only specification is that it should run noiselessly.