Arsenal defender Hector Bellerin has become the second largest shareholder in League Two Forest Green Rovers.
The Gloucestershire-based club have been recognised by Fifa and the United Nations as the world's most environmentally friendly team.
It went fully vegan in 2015 and became the world's first carbon-neutral sports club in 2017.
Bellerin, who wants to support the club's green agenda, said: "Forest Green are showing others the way."
The Spain international added: "So many people feel there's no solution to the world's problems, but Forest Green are already doing plenty.
"I'm so excited to be part of the FGR family. I'll be helping where I can, supporting people who want to change the world for the better."
The 25-year-old is known for being a socially conscious footballer and recently raised money to plant 60,000 trees in the Amazon rainforest.
His new role with FGR will see him work with chairman Dale Vince and the club on raising the environmental agenda in football - among clubs, leagues and fans.
Bellerin's shareholding is not above a threshold where it would be deemed a conflict of interest.
He added: "When I first played Forest Green Rovers [in a pre-season friendly in 2014], all I knew about them was that it was a long way from London!
"As I heard more about the club and its work, I knew I wanted to meet them and be part of it."
Vince, who has installed an organic pitch and has consulted with Premier League teams about also going green, said: "I like Hector's approach, his personal journey and the things he's trying to do - they make sense.
"I'm looking forward to working with him on FGR and this wider agenda we have a shared interest in."