The announcement last month that Richard Harvey would leave the top job at the FTSE 100-listed Aviva, the parent company of Ireland's biggest general insurer, Hibernian, took the City of London and the wider insurance industry by surprise.

But they were shocked to discover that Harvey would be leaving the double-breasted suit behind for a year to work with some of the world's poorest people.

"My wife and I became increasingly interested in the complex problem that people in Africa are poorer now than 20 years ago, " he said last week when we spoke in a seventhfloor office of Hibernian's new headquarters at Hatch Street in Dublin, overlooking the park behind the National Concert Hall. Aids is ravaging the African continent and he wants to call attention to the crisis.

"More people are dying of Aids per week than died in the [2005 Asian] tsunami. Look how the world mobilised for the tsunami.

Imagine if it mobilised like that around Africa."

When he smiles, which is not infrequently, Harvey looks a bit like Channel 4's Jon Snow, but his demeanour could hardly be more different. He engages, tries to answer even those questions that he'd rather avoid.

Harvey has successfully built the business, consolidating several companies under the one corporate umbrella, demutualising Norwich Union in the UK, seeing it float on the stock market, then going on the acquisition trail as the firm grew from a UK and Irish operation, to one with pan-European presence, to one that now operates in 25 countries around the world with growing businesses in Asia and North America.

His last year saw the firm buy its way into the United States with the acquisition of AmerUs for A�1.6bn (Euro2.4bn) and announce recently that its 2006 sales had grown to Euro45bn, up 22% on the previous year.

F Not a bad year to be your final one in the top job, by any stretch of the imagination.

But his last year was also marked by what should have been, according to Harvey, a fairly routine approach from one company to another about a possible merger - if there is anything typical about a potential transaction with a Euro25bn price tag.

At some point in the first quarter of 2006, Aviva approached another insurer, Prudential, about a possible merger that would have given Aviva a big footprint in America.

"These sorts of discussions happen all of the time in big business, " said Harvey. "People have discussions, they make propositions, they get turned down. And when it's a merger that's the end of story.

"We were a bit like Big Brother. We were having a private discussion broadcast to everybody else and sometimes those things look more vulgar when broadcast then when you're taking part in them. So there was a fair bit of hot air. But fact of the matter is it wasn't the exciting event it has become because of the oxygen it has received."

Harvey says he has no regrets.

"I wouldn't do anything different. It was a good and sensible thing to do. As with all mergers it takes two to tango. Only if the other partner is fully committed to it does it happen. Our approach and clear proposition leaked and made it into the public domain.

"It's our job to make proposals we think would make money. What we don't generally see is the reply and the debate in front of the newspapers, television and whatever else. Which is what happened in this particular case."

Fortunately, Harvey had other options.

After what he calls a "small leak" about the talks in January, he was able to come back to AmerUs and do a deal in midsummer. He says the timing already makes it look like a smart deal.

"I'm leaving Aviva in the best shape it's ever been in. Not just in a narrow sense, but it's grown from a UK/Irish business into a fully European business and is on a pathway to being a global business.

"It has momentum, " he says with emphasis. "You don't commit 10 years without feeling passionate about it."

Another topic on which Harvey is passionate is climate change. Beginning this year Aviva will be "carbon neutral", he says.

"It's a first step. It's relatively easy for an office-bound company, " he admits. But it was necessary in order to be credible telling others, including governments, what to do about mitigating further damage and managing the effects of the damage already done - as he puts it, "before you can start preaching".

"As a society we are finding new ways to be carbon neutral. Brokerage programmes are having an effect. Look at whole lifetime of a vehicle, not what it's doing right now. Are we recycling? A building like this, " he gestures around at the gleaming interior of the building opened officially that morning by Bertie Ahern, "that turns its lights off when it's not occupied. Purchase renewables-generated electricity. We reduced carbon emissions by 50% in the last five years."

He also believes that the insurance business is perhaps more sensitive than most to the issue, as it's so closely related to the bottom line.

"We know because we're good at foretelling the future in the insurance industry. It's what we do for a living, " he says. "We know what the odds are. We know what's happening. There's no point us preserving people's wealth in a long and happy retirement if the environment is uninhabitable or unpleasant. We will only have done half our job. So we're advocates of important measures to mitigate the impact of climate change."

Aviva's Norwich Union in the UK has been groundbreaking in developing hyper-accurate maps, as well as data on water tables and elevation, to get a better idea for each individual property, rather than by postal code, what the risks are from flooding.

Hibernian is in the process of doing the same to shape its risk assessments of property in Ireland. In some cases, this will mean higher premiums for properties built on a flood plain. But Harvey says that a greater number of his customers are actually benefiting because they aren't being unfairly lumped in with higher-risk areas.

Climate change is increasing that risk because increased temperatures mean more extreme weather events that can lead to bigger variations, for example, in the water level in rivers.

The most sensible policy, Harvey insists, is to pressurise planning authorities in Ireland and elsewhere to prevent further construction in flood plains, a practice that was allowed to go unchecked in England's southeast and has led to a greater number of floods here in Ireland as well.

"We built far too much there. Then we're reluctant to spend the money on the necessary infrastructural changes to control those extremes, which will be bigger. We've got to hold governments' feet to the fire on what their environmental ministries are doing on flood protection, water management, storm protection, et cetera."

As he works for the next year in Africa among the people most vulnerable to climate change, it is surely an issue about which we may hear more from Harvey in the not too distant future.

CV

RICHARD HARVEY Age: 56
Family: Married to Kay, with a son Adrian (33), daughter Kate (31) and daughter Jenny.
Background: 2001 to the present, group chief executive of Aviva; 1998, group chief executive of Norwich Union Interests: tennis, skiing, charitable work AVIVA Fifth-largest insurer in the world 58,000 employees Owns Hibernian Insurance