When Margaret Thatcher told him he was mad, Dr John Ashworth knew he had to talk fast to keep his job.

"I had published a report on climate change when I was chief scientist for the Cabinet and, at that time, climate change was regarded as one of the nuttier notions," he laughed.

"People thought I was mad and when I went to Mrs Thatcher with the report she looked at me and said are you seriously telling me my Government should be worrying about the weather?' I knew, if I didn't talk fast, I wouldn't have had a job!"

He has done all right, though. The Wivenhoe grandfather-of-14 is now Sir John, receiving a knighthood in the Queen's New Year's Honours List.

"This year's list was particularly long. I don't know what the Prime Minister was thinking!" said Sir John, modestly.

Being called Sir embarrasses him.

"I would certainly use the title if I was trying to get a reservation in a restaurant or booking a flight - you never know, I might get upgraded! But certainly not in normal life, and not by people who have known me for years."

The knighthood wasn't a total surprise, though.

Sir John, who has degrees in chemistry and biochemistry, was a foundation professor of biology at Essex University in the 1970s.

He was seconded to the Cabinet Office to work as chief scientist under James Callaghan and Margaret Thatcher. He commuted from Wivenhoe to London everyday.

"The trains weren't any better back then," he laughed, mischieviously.

But having also worked as vice-chancellor of Salford University, as director of the London School of Economics and chaired the boards of the British Library, Institute of Cancer Research and Barts and The London NHS Trust, an honour of some sort was bound to be on the horizon.

"My predecessors have been honoured in one way or another and when you do these kinds of jobs, and you do it well, it's often customary to give honours when the person retires.

"But when you get the letter you do get a thrill," said Sir John.

While it may not have been completely unexpected, it is clear Sir John, who is now retired, didn't pursue his career in science and academia in the hope of becoming a knight.

When he talks about his former career he speaks with passion, pride, and plenty of humour.

He is particularly proud of his time with the British Library, when the new building was being built in Euston Road, London.

"It was widely held to be over-budget and had taken 30 years to build. Prince Charles referred to it disparagingly and it was a nightmare," he said.

"I was the chairman who finally got it open and working. There were 1,000 legal suits between the library authorities and the contractors, so sorting all that out was quite a business."

But the "nightmare" was worth it.

"Now it's one of the best research libraries in the world and memories of the old days have gone. It was very satisfying," he said.

Sir John isn't the stereotype academic and scientist.

He's very jolly, full of humour, and seems to enjoy a good chuckle.

Sir John retired in the summer and is loving every minute.

As I spoke to him, four of his 14 grandchildren were "stuffing their faces with toast", as he endearingly put it.

He loves having them, which is lucky because the seven children he and his second wife, Auriol, have between them will probably mean there are going to be a lot more grandchildren, and great-grandchildren.

But his grandchildren aren't his only passion.

"I greatly enjoy sailing," said Sir John. "Some people take up golf when they retire but I can't stand golf.

"I love sailing - the fact you have to play air and water off against each other to get to where you want to go is wonderful. It's like a puzzle you are constantly solving."

When he says he loves sailing, he's not just talking about playing captain.

"I have always worked in offices and never did anything with my hands. Now I'm retired, I have the time to make something so I'm building a boat," he said, sounding chuffed to bits.

"It's a 16ft-long rowing boat with sails. I'm not very good at it but I don't think it will sink!

"I've been building it for over a year and it will launch in March."

"My ideal trip would be sailing in the Balkans in my own boat. It's a place I couldn't go to as a youngster and I would love to see it by water," he said.

Now he's retired he has plenty of time to make his dream a reality, and no knighthood is going to get in his way.