Sata, 77, died at King Edward VII Hospital in London, where he was being treated for an undisclosed illness. Until his death, the Acting President of Zambia was Edgar Lungu, the Defence Minister, but Scott said he had now taken the role in accordance with the constitution. This made him Africa's first white head of a democratic government, "except maybe the Venetians in the days when they ran the world".
Scott said: "Everyone is getting used to calling me 'Your Excellency', and I'm getting used to it. There are truckloads of guys following me on motorbikes. It's very strange."
Asked why he thought he had been chosen to be Zambia's interim leader, he pointed to his "seniority within the party, in government", adding: "The President kept me as his Vice-President despite a lot of efforts by people to get me taken down."
He said he last spoke to Sata several days ago. The pair were old allies and friends. Despite there being only 40,000 whites among Zambia's 13 million people, there was little surprise over Sata's decision to appoint a white deputy. Scott, a father of four, is widely credited with rescuing Zambia from a drought as Agriculture Minister in the 90s.
In 2012, he said: "I don't think Michael thought it was a racial thing, he just thought it was a good idea. I've been involved in politics here for a long time. As a schoolboy I was involved in the liberation movement."
However, he added: "You see people's jaws drop, they think there's been a mistake with the seating plan or something."
Scott was born in Livingstone with a Scottish father, Alec, and English mother, Grace. His Scottish father emigrated to the British Protectorate of Northern Rhodesia in 1927. His mother was English.
Scott studied mathematics and economics at Trinity Hall, Cambridge, and later took a doctorate in cognitive science from Sussex University and lectured in robotics at Oxford. He lives with his wife, Charlotte, on a farm outside Lusaka, the capital.
The plain-speaking Scott is popular among his countrymen. He and Sata have been praised for restoring some of Zambia's tattered infrastructure and health and education systems.
Scott has also spoken of the need to keep controversial leaders such as Robert Mugabe within the diplomatic fold - and claims to get along "like a house on fire" with the Zimbabwean President.
He received the accolade "scaly old dude" from Bush when the former US President visited Zambia to support a charity after leaving office.
- Telegraph Group Ltd