The economies of Northern Ireland, England, Wales and Scotland benefit hugely by all being part of the United Kingdom, according to one of the UK's most influential business organisations.
The Confederation of British Industry (CBI) said all four nations are stronger together and benefit in many ways from the UK's single market and the single economic, fiscal and regulatory frameworks.
Mr Carney warned business leaders at a lunch in the city that there is the risk of a eurozone-style crisis if an independent Scotland shared the use of sterling with the rest of the UK.
He said the region would need to cede some of its national sovereignty if it gained independence at a vote later this year and decided to continue using the pound.
John Cridland, CBI director-general, said the risks associated with independence are high.
"The UK Government has made clear that a currency union with an independent Scotland would bring with it significant challenges, including the fact that interest rates and borrowing costs would be set outside Scotland," he said.
As an example, Mr Cridland said the recent eurozone crisis proves the difficulties involved.
"As the governor highlighted, successful currency unions need strong fiscal agreements and a banking union, with common supervisory standards and resolution mechanisms. The negative effects of not having these structures in place have been starkly illustrated by the eurozone crisis.