There is “no alternative” but to green Britain’s economy, William Russell, the new Lord Mayor of London, has insisted ahead of his meeting today to talk green finance with Nicola Sturgeon and business leaders from across Scotland.

In an exclusive interview with The Herald, the 692nd holder of the historic role in the City of London insisted his job went way beyond the Square Mile of once bowler-hatted bankers and that he was now the Financial Ambassador to the whole of the UK.

There might be an irony in the fact that the 54-year-old investment banker will spend the next year on a mission; globetrotting, jumping on and off planes, trying to sell Britain as the capital of green finance; the new phenomenon, which sees the environment placed front and centre of business investment.

Today, as part of that mission Mr Russell will be in Edinburgh, co-chairing alongside the First Minister a green finance forum with attendees including HSBC, JP Morgan and Legal and General. The event is a “call to action” to find more investment for green projects in Scotland.

The greening of finance is catching on fast. A new index of 6,000 companies has been created to assess their green credentials. Roughly 230,000 people are now employed specifically in the green sector.

The City of London chief quoted a colleague, Mark Carney, the Bank of England Governor soon to become the United Nations’ special envoy for climate action and finance, who said about green finance: “’Every financial asset will be repriced. Those companies that anticipate will be rewarded handsomely, those that fail to adapt will cease to exist.’

“That’s the message,” declared Mr Russell. “The momentum is such that every CEO of every company[would say] green finance is the biggest issue they have to look at.”

The race is on to occupy the “green space” and London and Britain, the Lord Mayor insisted, were ahead of the pack.

But Would the City of London chief be so interested if there was not money at the bottom of the “green space?”

“The answer is, yes, there is money in it, which is why you get the private sector involved. But it has to be done. If there wasn’t money in it, I would still argue it is going to get done because the human race has worked out you have to do it.”

Mr Russell pointed to the floods and the fires afflicting humanity and that something must be done. But better Britain was at the forefront of this new economy than another country.

“The UK has this opportunity. Like fintech we have an ecosystem here that is second to none and as a country and as a city we have a chance because if you said to me: ‘Who is your biggest competitor?’ I would say New York. No one is talking about green finance in New York and we all know why; because they have a President who doesn’t believe in climate change.

“For us, it’s a huge opportunity to be a centre for that,” he declared.

Interestingly, the five global threats identified at last week’s World Economic Forum in Davos were all environment-related.

“Let’s say you have a house on the coast in Scotland. You have a mortgage on your property. It was worth 10 years ago £500,000 and you have a £400,000 mortgage and there is erosion. That’s going to be written off; your house is worthless. And that is what people are beginning to recognise. That there is a massive finance risk here to everybody,” explained Mr Russell.

The City of London Corporation has recently launched the new Green Finance Institute together with the UK Government to bring together the public and private sectors to collaborate on green finance.

But the “huge jewel in the crown,” insisted the Lord Mayor was COP26, the global event in Glasgow in November, which will bring together some 200 world leaders and 30,000 delegates.

“This is such a big moment for the UK. COP25 was not what we wanted. That’s why the Prime Minister and the Cabinet Office are taking this so seriously because it is an opportunity, particularly at this time, for us to deliver.”

Fittingly perhaps COP26 will be the Lord Mayor’s swansong in his ambassadorial role. Green finance will be front and centre yet again. “A good way to end,” added Mr Russell.