What a Attention Seeker Title, with hollow matter. Post about the carrier, its capabilities, then ask the members how it could be a threat and how it could be neutralized.
For the question you asked, it is very difficult to distroy a Carrier, because it do not travel alone, and their are many layers of security. A diesel Electric Subs threat could be easily neutralized by increasing the ASW capability.
And due to the sheer size of the modern Carrier, I don't think a single torpedo is more than enough to damage the carrier seriously and to come such close to the carrier to fire the torpedo would need great luck and stealth on the ocean.