M.F.
Two years old think they are the center of the universe, so yes I do think he's jealous of his new sibling and has no other way to tell you. What you need to do is be consistent with him when he acts out inappropriately. When he whines, tell him you cannot understand him and they he should use his words or show you what he wants of you. If he continues to whine, tell him you do not like it and that if he continues, he will have to play in his room until he can tell or show you what he needs. Tell him you know it's hard for him to share you with the baby, but because he is a big boy now, the baby needs you to help it grow and that you need his help also with the baby. Give him little helpful chores to do - get a toy, pacifier, rag, diaper...whatever. Tantrums - he goes immediately to his room or time-out area and you tell him when he can calm down and tell or show you what he beeds, he can come out. Ignore his screaming while you are in his presence - give him no attention - even negative attention will feed his tantrum. The important thing is to be consistent with this for a week or more and you should see a change. Blessings!