If you are ever going to be doing any pruning or trimming of trees and shrubs on your property, you should consider buying a pruning saw. They come in a straight frame style in 12, 15, 18" or more. The blade as cross cutting large teeth that are extremely sharp. I have a 15" one myself and a 20". They make short, quick work removing any limb.
Carpentry or hand saws are not really suitable for tree work. Their "small teeth" easily clog turning a relatively simple job into a nightmare.
They make a couple of sizes that have a blade that folds back into the handle.
When sawing any limb 2" or larger, it is a good idea to make a shallow cut of about 3/8" on one side of the limb. Usually the underside. Then go 180 degrees to opposite side of the limb sawing through to meet your 'starter cut'. This will insure a clean, precise cut each and every time!!!