Gallagher: "I always look at the motives behind each scene. You can play that out tonally with how you express yourself or you can do that with your physical expression, your physical presence. So I always think about what physical presence I want to embody in each scene."

Gallagher: "There are important things happening right now that are going to affect everyone’s future. We are currently in the sixth mass extinction, and 60% of animal species have gone extinct. They are the canary in the coal mine for humans. I wish people would wake up and I’m trying to wake them up. I’m deadly serious about these issues."

Gallagher: "Because of social media today, the youth have more power in their hands than they've ever had."

Gallagher: "I don’t care about selfies, although I like sharing what I’m doing with fans. I grew up around other celebrities and some just want to grow their following but not use their influence for anything good. I have found my posts have cost me at least half of my potential following because kids my age are mostly turned off by posts about the planet or against corruption, but the ones that stay are the ones that care - so by definition they are the smart ones, and I prefer a smart following over a bigger one. And I would rather be a caring person over a non-caring one."

Gallagher: "I'm 15 and everything I'm doing right now is really exciting to me, so, actually, whatever I'm into at the moment, I'm somehow able to stay very focused on. I just keep moving forward."

Gallagher: "Well, it’s a bit of a coincidence that I landed this role of a guy who’s trying to save the world from an apocalypse and I’m also trying to save the world from an apocalypse. Actually, I think individuals have a lot of power. If everyone starts small with just one thing, just one change, that will have a positive effect, and also yes collectively it can be stronger."

[On being appointed as the youngest United Nations ambassador ever]

Gallagher: "It is a great honour and even bigger responsibility, and hopefully it allows me to reach a wider global audience with my environmental messages."

Gallagher: "I could probably have more followers if I took more photos of myself and maybe did some dancing like others. Lots of people do not like my posts. Ultimately, I’m an optimist and I think I can inspire change on a global scale."

[On his songwriting process]

Gallagher: "For me, it starts with a feeling that sort of leads to me writing and capturing the words and then the melody. It works best when I’m just relaxing; following my heart with the time just spent making music for fun. I might work it out on the piano or the guitar in parts. Record it, let it sit, come back and work on it. It’s really something that just flows artistically so if I’m in the right head space, maybe inspired by where I am or finding a moment to myself, sometimes a song just comes to me and I have to quickly get to it, so I don’t lose it!"

Gallagher: "This is a toxic cycle that is coming to a dark ending very soon. The only thing keeping it going is greedy and corrupt governments who care more about money than the future of the planet."

Gallagher: "What I try to do on my Instagram is provoke discussion and share environmental and sustainability messages."

Gallagher: "So, before we even talk about overfishing, or over-breeding of cows and pigs, or deforestation, we are already killing off the oxygen supply with the industries that make our 'stuff.'"

Gallagher: "Making music is relaxing and challenging at the same time. When I’m in it, it’s like a flow that has my whole concentration. I think it’s the same feeling you have when you are creating maybe a painting, or cooking, or doing something absorbing and fun."

Gallagher: "I like playing music with people around me. The feedback and interaction is cool."

Gallagher: "The question is, can people acknowledge the science or is it so anxiety provoking they can’t even think about it today? We are growing too fast as a species for this planet."

Gallagher: "I believe that if today's youth work together raising our collective voice, we can affect the positive environmental change that Planet Earth needs so desperately."

Gallagher: "Billions are spent in advertising every year to make you think horrible things are good for you and to get your money for things that will kill you."

Gallagher: "It’s just a matter of time before the cable snaps and we all go extinct at 7.5 billion. But every floor, another person crams their way on and no-one can get out. This keeps happening and we can hear the cable creaking and ready to break."

[On his EP, Blue Neon]

Gallagher: "The songs are about things that matter that you can’t see, but can feel in your soul. And how the passing of time affects those things. I’ve put in a lot of layers."

Gallagher: "Just getting to study and bring Number Five to life was fun it itself just for an audition. To inhabit that space of a multilayered person like Five. In a weird way I feel like I was born to play this character even though I’m nothing like him. Except that I've never felt my age my whole life. I sent them this tape and then they called me and there were meetings and more auditions in person and then when it all came together, I knew I was probably the luckiest person ever."

[On producing his own songs]

Gallagher: "Producing it myself is really allowing me to focus on certain parts of my music and songs without distraction from outside sources or influences. Ultimately, it’s a very satisfying feeling."

Gallagher: "I don't know that I would say I've felt like a 58-year-old, but I've never felt exactly my age, or in the right place."

[Interviewer: Number Five says to Luther: "There's no such thing as good guys or bad guys. There's just people going about their lives." Do you agree or disagree with him?]

Gallagher: "It’s a heavy line. I mean, objectively you could say Hitler is a bad guy. But he didn’t think he was, which is weird. He thought he was a good guy. I could point to some of our politicians and what they are doing to our environment. They are bad guys, but they don’t think they are. I think Five is telling Luther to stop focusing on his own morality and think about the context of the problem of saving the world from the apocalypse at any cost, because the cost will be minimal compared to the moral directive to save 7 billion people from the end. Luther wants to live by a code. Five has no code and just deals with things as they happen. I agree with the idea of context."

Gallagher: "When I’m writing, it’s really the interpretation of a feeling or feelings that is coming through. Maybe memories combined with something I’m feeling right now, or something that triggers something else."

Gallagher: "I've always looked at the world of Umbrella Academy' with the world that I live in."

Gallagher: "Teens say there's nothing I can do because I have no vote. The truth is, the only vote that matters is how you spend your money and who you give it to. Each coin is giving power. Notice and be careful who you give your power to."

Gallagher: "I think people want to feel that it is possible to overcome differences to work together in times of stress. Maybe that's why so many people are looking for an alternative to the standard superhero movie or TV show. They are looking for characters with more dimension."

Gallagher: "Quarantine has really affected me in terms of thinking about what the rest of the world is going through and what isolation within a small space might be like."

Gallagher: "I live in the same house as I did when I started acting. My life hasn't changed. Only people around me have changed with how they look at me."

Gallagher: "I found out that the animal agriculture business has a huge impact on our climate, so by cutting down on your meat and dairy consumption, you can have a huge impact and help the environment."

Gallagher: "I get to play a 58-year-old time-traveling assassin. The role had a lot of layers to it that I knew would be fun to break down and figure out the motives behind."

Gallagher: "As far as what part of myself I brought to Five, I've always considered myself not really my age."

Gallagher: "I get a lot of hate posting vegan, environment and pollution stuff."

Gallagher: "When I key into the character of Five, I'm generally drawing upon a mental state - not so much thinking about the 58-year-old side of him, just the way he reacts to things."

Gallagher: "You should cut down on your plastic consumption. Go get a reusable water bottle."

Gallagher: "I wrote Time' while I was filming 'The Umbrella Academy' and it is a tribute to the journey of my character on the show as well as to the music of My Chemical Romance, but it is also about the idea of living fully in the present moment."

Gallagher: "Exposure is this thing people think they want but at the end of day it doesn't matter."

Gallagher: "With social media, some people are supportive and there are some haters and people who make fake accounts. It's out of my control."

Gallagher: "With any second season, it's a tricky balance between keeping what fans loved and also making sure it feels new."

Gallagher: "It's very fun to see how fans react and theorize and get excited about what might happen in future seasons."

Gallagher: "When you are ten years old and people are screaming your name, trying to grab you at the Kids Choice Awards, and you go to the mall and groups of girls start following you around, it's very unreal and like a dream. I can't say I get used to it, it's always been a little freaky."

Gallagher: "I don't know that Five was a good person before he got stuck in the apocalypse, in a way that really made him a bit more open-minded."