1. CND marches

FROM the age of seven, I was marching through the streets of Plymouth with my parents on the Campaign for Nuclear Disarmament (CND) marches.

I also went to some of the huge marches and rallies in Hyde Park in London in the 1970s, where there would be a quarter of a million people.

My parents were always active in CND and they were going on marches in the 1950s before I was born.

They lived in Ireland, but they came across to take part in the marches to Aldermaston, where the nuclear weapons were made and stored. For them the nuclear disarmament campaign was lifelong, and it stuck with me. It’s still extremely close to my heart.

Getting rid of Trident is the top reason why I support Scottish independence. There are many reasons but that is the key one, and the one thing I could guarantee would happen. Maybe not immediately, but quite soon, we would get rid of it. Trident is an abomination. It would be so expensive to move it somewhere else, so hopefully it would be the end of it for the UK. That would be a great service to the world.

2. Genesis

Peter Gabriel

MUSIC is really important to me and always has been, but a key moment in that musical education was a gift from a friend on my 16th birthday. I was given the cassette of an album called Seconds Out. That introduced me to prog rock more generally.

I always find that music is a great place to lose yourself when times are hard. It’s also a great place to give you energy when you need it. It was a really fundamental moment when I discovered Genesis and progressive rock. I’ve followed the career of Peter Gabriel since. What a musician, and so much social goodness.

3. Cultural awakening

THERE are three elements to this really. When I was about 19 and at St Andrews University, I was in play called Savages, about the Brazilian government wiping out Amazonian indigenous tribes and trashing the rainforest.

It was written in 1970s, I was in it in the 1980s and, sadly, it is still relevant. I played an anthropologist and I told the story of a tribe who were wiped out, and it stuck with me. It’s part of the reason I do what I do.

Second, my father was a great reader of science fiction and I picked up on it, particularly a novel called The Sheep Look Up by John Brunner. In the 1970s and early 80s, science fiction was usually about the world which had been wrecked by pollution and corporate greed or been destroyed by nuclear war.

The third element is seeing Blade Runner when I was 18. Again, a this is a dystopian future where corporate greed and pollution were destroying the world.

These were all formative to me as a world that I desperately wanted to avoid.

4. John Seed

I WENT to a talk at Appleton Tower in Edinburgh University around 1989, by a man called John Seed, who runs the Rainforest Information Network in Australia.

It was a very striking talk about how we were destroying all the big forests around the world. However, the key thing he said was that it was our generation that had the power to do something about this, and if we failed to so do it would be too late.

It might sound sort of trite, but it really did strike a chord with me at the time and I thought I had to do something about it.

I took that message extremely seriously, and it really did shape my life.

I was finishing a PhD in astronomy at the time, but then I went to Glasgow Caledonian University to do an MSc in energy systems and environmental management, which is quite a mouthful, but that was my path to get myself skilled up enough to do something about saving the environment.

I was always active in Friends of the Earth local groups in Edinburgh and Glasgow, but I wanted to get into this type of work as a full-time profession.

5. My brother John

MY brother killed himself after having a chronic illness, it was something like ME, for about eight years. He had finally had enough and took his own life.

Obviously, when that happens to you, it has a huge impact on your life.

The two of us gave each other a lot of support as we were growing up. When I was away at university and then when I was in my first job we had a lot of contact.

His death left a massive gap in my life. I had a sister as well, but we didn’t really get on; we didn’t really speak, so there wasn’t that same mutual support.

To this day I still think of John, particularly when there’s something he would have enjoyed.

6. Simon Pepper

THE late Simon Pepper was my boss at the World Wildlife Fund when I arrived there in 2003. I went there from Friends of the Earth, then came back here. He was a real inspiration to me and virtually everyone who came across him.

He was a great boss and I worked for him for about two and a half years. I learned a huge amount about diplomacy and about playing the long game.

When we’re passionate about an issue it can often be easy to get frustrated and want everything to happen immediately, but that is rarely how the world works. Learning to play the long game can have benefits.

He also taught me about running an organisation: the systems, people, budgets and everything else that is involved. He is much missed by everyone who knew him.

7. The personal connection

MY former partner and I were together for 19 years. We were both interested in the environment and when we began our relationship she had three children.

The eldest was 14 when we got together, so we went right through all the stages of them growing into adulthood ... and then there were the grandchildren.

Obviously there were many good things about this long period of my life and it changed my thinking in a fundamental way.

Originally, trying to save the planet was quite an intellectual thing for me, but when I had responsibility for children and then grandchildren, it became a deeply personal thing for me to achieve.

It makes you think much more about the future as well as the present. It’s not a question of what can I achieve in my lifetime, it’s about the state I’m going to leave this planet in when I’m gone.

When I did the PhD in astronomy, I would think about the sky and the stars and the planets, so it was intellectually easy for me to think, “Right, this is our planet. I had better do something about it”. It was something I believed in strongly, in that cold, intellectual sort of way, but helping to bring up children and then grandchildren gives a much more personal connection to the future.

8. Selfless pursuit of a cause

I’VE met some incredibly inspirational people, at Friends of the Earth and WWF. One was a man who risked his life every day in a war zone, in order to protect mountain gorillas in the Democratic Republic of Congo.

You know, I get annoyed that the government doesn’t do what I tell them, but this was a man who had two passports and when a truck showed up full of men with guns he had to guess which side of the conflict they were on. If he had shown them the wrong passport, he would have been shot.

It got so bad that he and his co-workers had to walk 1000 miles back to the capital because it was too dangerous to travel any other way.

Then there were two women I worked with who were key players in bringing peace – one in the Balkans and one in Chechnya.

They were part of the women’s peace movement that had an important part to play in bringing peace to those areas.

The woman in Chechnya led a peace march by women who had sons in the army in an attempt to stop it. The role of women in trying to stop these conflicts can never be underestimated.

The dedication and selflessness that these people have to the causes is more than inspirational.

9. The climate coalition

IN 2006, I got a group of people together to talk about whether we should create a climate coalition in Scotland. This included people from environment groups that I already knew, but also people from the development groups such as Oxfam, Christian Aid, and Sciaf.

Those discussions led to the creation of Stop Climate Chaos Scotland, which is still going. I served on the board for 11 years.

Sometimes it’s quite hard work working in a coalition, but I firmly believe that we can achieve more by working together, so I’m very supportive of coalitions in general. But that day, when I brought those people together, and we decided, “yes, let’s create this thing” ... that was a big change in my life.

As a young boy on CND marches in Portsmouth with my parents and being part of a quarter of a million throng of people in Hyde Park, I could never have envisioned being able to play my part in this way.

Working at that level and interacting with ministers, including the First Minister, and working in a coalition which has 60 groups in it ... it’s possibly the largest coalition ever created in Scotland.

10. The youth strikes

I’VE been a paid environmentalist working for Friends of the Earth for 25 years now and for all that time I’ve been bashing my head against a brick wall, because the environment just gets worse. Yes, we make progress, but there’s always more to do. So it can be depressing, and it can be frustrating.

When I went to the first of the big gatherings outside Parliament, there were about 7000 schoolchildren. They had organised themselves. They gave speeches which were actually interesting, unlike those adults usually make.

I stood there and my heart suddenly felt lighter. I knew why I was doing this and why I needed to go, because of these 7000 schoolchildren.

They have done great things but one of those things for me is to restore my will to get stuff done. Just being there with them is so inspiring.

As a child, I would have definitely been there with them if there had been that kind of youth activism when I was that age. They have been just been knocked back by Edinburgh City Council about their march route along Princes Street, so they’re working out what to do next, but they absolutely will. They don’t give up and it’s so inspiring to work with them.