The Climate Crisis

Fruit tree grafting is very easy.

Take a twig cutting (a few inches long at least) cut at a thin diagonal. Line that up with a similar cut on the target plant so the bark lines up as much as possible and wrap. The bark is where the cut will heal so the branch survives.

If you get multiple varieties of apple on the same tree the tree can now self-pollinate.

It can get more complicated, you can use special ties or have a tree salve for the cut. But that's the basics.

Anyone can do it with some practice and a little studying to make sure you're grafting compatible fruits.