Wole Soyinka has flown into town to help to save the environment. It is the occasional job — thank goodness — of the Nobel laureocracy, as it is of constititional princes, to try to redeem the world, and Soyinka, ever the activist, is taking part in the climate-change conference at St James’s Palace, Central London, entitled “The Fierce Urgency of Now”. There is an obvious paradox that such involvement means taking yet more flights and staying in large, depersonalised luxury hotels, far from the smell or sounds of city and bush.

The laureate himself acknowledges the contradiction. “Unfortunately policies are not made in villages, they are made in places like this.” But then the Nigerian poet, playwright, novelist and memoirist sees the unexpected bright side of our Hyde Park location. “This hotel is at least next to a bit of Nature. Here, ironically in places like England, it strikes me sometimes that you have a greater respect for Nature than where I come from. You don’t destroy your trees as fast as we do in so-called developing countries. If I have any qualification to be here at this conference it is because I resort to very strong action in my own environment to stop trees being beaten up.” He looks mischievous and giggles. “I won’t say what kind of action it was.”

It is true that he won’t say. If he is coy about his past activity, it’s perhaps because some of his action has been at the edge of legality: for a poet Soyinka has an activist’s record. Forty years ago, campaigning against a corrupt local politician, he took over a Nigerian radio station for a few minutes at gunpoint. Some time later he and some accomplices travelled to Brazil to steal back, from a wealthy private collector, what they believed to be a cultural treasure that had been stolen, a bronze head of the Yoruba sea god Olokun. The head, in the end, turned out to be a plaster replica.

What he will say is that the people who have run his country have not cared much for its trees, or for anything. “I mean many developing countries, when they want to build an extension to a city, the first thing that is done is to bring in the bulldozer and wipe out everything. Come to Lagos,” he invites me rhetorically, “and I’ll show you what happened under previous regimes. We are still suffering serious flooding as a result of erosion caused by the destruction of trees and vegetatation.”

The Lagos of his childhood has been utterly destroyed simply for the sake of “high profit yield”. “I grew up with canals,” he recalls, “I used to go on holidays to my relations in Lagos and I know how the canoes used to thread the canals bringing food and people, and water was part of the natural habitat of the city. Then the military began to sandfill the canals and the lagoons. You will not believe that they ever existed, those lagoons. The generals allocated to themselves the plots and sold them for astronomical prices.”

Lagos had green spaces, he says, places “where students used to go and study at night under streetlamps, where civil servants would retreat during their break, where lovers held hands. There was one place called Love Gardens. It was totally consumed by land greed.”

Today the Lagos authorities are attempting to restore some green space, but such initiatives are too few. A “wrong notion of development” prevails. “If these politicians could understand that people in the countries they are trying to imitate are rethinking — have been for a few decades — and are taking measures to preserve what is left of their greenery, then maybe they would pull back just a little bit.”

Soyinka is inclined to be generous to us in the West, because he thinks we’ve changed. “I have never ever forgotten the experience of coming to England for the first time — it was 1954 — and being horrified by the soot. I wrote home about it. I couldn’t believe human beings lived in an atmosphere where when you blew your nose, better not look in your handkerchief . . . because what you would see was,” he laughs, “black. Pitch black.

“But then there came an awareness within European cities. They had come to accept their public buldings, their tenements, having grey-black as their natural colours. Then they started being cleaned up, throwing light on natural structures. We could see buildings come alive, see patina on bricks, see veins in marble, in public statuary. ‘My goodness,’ I thought, ‘I’m not crazy, these people have woken up to what’s happening’.”

There’s nothing sleepy or tired about the poet, for all his 74 years and constant jetlagging. He looks no more than 64, with an unwrinkled, affable face and an explosion of white hair and beard, seemingly just ready for shearing. His voice is not reedy but deep — so deep that I have to lean in to catch his words.

I have always been interested in Soyinka’s engagement. He has been imprisoned, exiled, continuously busy with campaigns on democracy, human rights, against genocide, as well as being involved in the politics of Africa. And all this while creating a brilliant body of work that would suffice for three artists. Like the young man to Father William, I ask him why he does it.

“It has to do with temperament. No one believes it when I say it that I am a glutton for tranquillity. People grab you for some purpose, which is not even life-enhancing. It’s a bit much, as we used to say, and there’s a huge section of me that resents it. I must confess.” He laughs. “Sometimes when the new generation comes along and says, ‘Shall we do this or that?’, I say ‘Listen, listen, listen, on my way out I will surprise you one of these days, when I tell you I’ve retired — get out of my life, get out of my face!’ They say, ‘We know you’. ‘You will be surprised,’ I tell them. ‘I won’t wait until you’ve killed me. I’ll kill myself off, symbolically’.”

But he doesn’t believe himself on this. “People like me cannot function if their space is not clean, if there are actions that rebuke their very nature. There are artists and writers who take no part, and they are important members of the artistic community. They are able to shield themselves. I envy them. I wish I was this kind of artist. I know what it’s like when you can exist within a cordon sanitaire and I value it intensely. If I could create this carapace, the way I can working in a plane, crossing the Atlantic — it’s marvellous. That’s my hour, for my creativity. No one can touch me.”

He argues that the theatricality of politics repels rather than attracts him. Some leaders “exceed what the playwright can invent”. He gives the example of the Sudanese leader, Omar Bashir, who “guilty of sending his soldiers out raping, massacring, poisoning wells in Darfur, then goes on television with a spear and a robe that probably doesn’t even belong to his tribal culture, and prances around saying, ‘They’re trying to recolonise us’. After that, what do you want to put on stage? It cripples you. How can you match that level of theatricality? How can you match Mugabe’s moustache?

“That’s why I resent people like Obama — just when you’re about to give up, they come along and you say maybe there’s life in it after all.” He laughs again. “I know you think he’s Kenyan, but I know he’s half Yoruba, like me. I’m waiting for the DNA tests.” Soyinka doesn’t believe, however, that Africa should make any special demands on Obama just because of his ancestry, and indeed worries slightly about the President’s vulnerability. “It’s clear that he’s a thinking president. But I hope he has the cunning that his position requires.”

And Soyinka. If he had been a bad writer, could he have been a politician, or have taken up arms? “If it had been that way, I might be dead by now. I very likely would have thrown myself in directions that would have been fatal. Like the poet Christopher Okigbo, who took up the gun in the Biafran war. When the moment came, he made a choice — very different from somebody like García Lorca, who did not pick up a gun. You just never know when the breaking point is. I came close to it several times.”

In any case there are other ways for poets to get into trouble. As we speak the Padel case is coming to its tatty end. “Oh, there you are,” says Soyinka, enthusiastically, “even a zone that is supposed to be isolated from this kind of thing.”

It turns out that the wronged candidate for the Oxford poetry chair, Derek Walcott, had been staying with Soyinka in Nigeria just before the story broke. “I felt personally about this,” Soyinka says, “I mean, for God’s sake. There but for the grace of God go I. It can happen to any of us, especially in countries like Amercia, where you can be sued for admiring a student’s skirt. And to rake this up, how many years afterwards?”

Derek Walcott, he tells me, is one of the three finest poets in the whole wide world. “I look out for him, he looks out for me. So when this thing happened I felt heartbroken for him. I felt heartbroken for the muse of poetry. So this morning, when I went to the BBC, in the lobby I saw this tickertape on screen, saying that Ms Padel had resigned, I thought, there’s something called poetic justice.”

Then there was the suggestion that, at 79, Walcott was past sexually harassing anyone. “As someone very close to Derek’s age,” twinkles Soyinka, who will never cease to be active, “I resent that statement.”

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