You will have to undergo a major operation and be under a GA. It will take a lot longer for you to recover and you have a greater chance of the tubes growing back! He will be able to have it done under a local and be able to be back at work the next day. (Note: He will probably whinge a great deal more than you would though so it is something to consider )

Also (I am assuming) that you have been responsible for the contraception for most of your relationship and you have had to give birth, breastfeed etc. He is now offering to be responsible for something - let him If he feels that he is done with fathering then I would let him make that decision. My DP has had it done and it was really no big deal, he has had no issues and he is really glad that he has had it done.