On September 18, the people of Scotland will be asked in a long-awaited referendum: "Should Scotland be an independent country?" However,the issue of the economic implications of an independent Scotland have come to dominate the referendum debate.
(Read more: Scotland independence: Widnae it work?)
The Governor's speech followed an earlier meeting with Alex Salmond, first minister for Scotland, where Mr Carney is understood to have laid out some of the issues raised by Scottish independence.
In Scotland, the 'Yes' vote has galvanized popular support ahead of the 17 September vote and Mr Salmond has said he would like to keep sterling, given it is an asset that needs to be shared between both countries.
Carney outlined the benefits of shared a currency, namely the elimination of transaction costs, reduced uncertainty about currency movements and helping to promote integration by removing one of the barriers between markets and improving transparency.
While the BoE Governor said it was not his place to decide whether Scotland would be better or worse off under independence, the Governor's speech contained warnings about sharing a single currency without the right measure of fiscal alignment.
(Read more: Europe moves to banking union with blueprint for failing lenders)
The biggest area of concern for Mr Carney was the need for a stable banking system. The combined balance sheet of Royal Bank of Scotland and Lloyd Banking Group, which are headquartered in Edinburgh, is almost ten times the size of the Scottish economy.
The UK Government is unlikely to want a currency union that would allow an independent Scotland influence over domestic monetary policy whilst simultaneously leaving UK taxpayers on the hook for Scottish banks.
Carney said the current banking union between Scotland the U.K. had proved durable and efficient: "Its foundations include a single prudential supervisor maintaining consistent standards of resilience, a single deposit guarantee scheme backed by the central government, and a common central bank, able to act as Lender of Last Resort across the union, and also backed by the central government."
However, the euro zone crisis had shown that without such arrangements, disaster was around the corner, and Carney said that an independent Scotland would have to "consider carefully" how it would retain the current union in a way that was consistent with its own newly-acquired sovereignty.
(Read more: UK to make debt pledge ahead of Scotland referendum)