I have a tree think it is a spruce, about 40 years old

It may be insects,weather burned,or not enough water.Check for signs of webbing or stickiness on the branches,if there is no noticeable evidence it may just be due to uneven temperatures

Life expectancy of most spruce trees is closer to 200 years, but that is as part of a stand of trees.

Solo trees or a line planted as a windbreak may have life threatening damage in as little as 50 years from normal exposure. Harsher than normal storms, infestations, or disease can shorten their lives further.

If your tree was planted as a landscaping statement piece, it may just be time to let it die.

If it is part of windbreak, check for pests or diseases that might spread before removing the affected tree. Consult a local arborist if needed.

Sounds like red spider. Go to your nursery or hardware and get a spray for it. Should take care of the problem nicely.

I just learned that mistletoe is a parasitic plant that attaches to trees and if not removed will kill the tree by stealing all the nutrients. Look up photos of it and then you can see if it is on your tree.

It could also be a fungus which also makes the needle s and branches turn red. Have an arborist or nursery look at it to be sure.

I read that you can amputate the branch, but if it's attached to the trunk your in trouble.