The Duke of Sussex, who quit royal duties last year with Meghan Markle for a new life in America, has launched his new campaign with conservation group Re:wild.
In a joint opinion piece for The Washington Post, Harry and environmental activist Reinhold Mangundu described the Okavango River Basin in southern Africa as a “natural beating heart that has nourished humans and wildlife for generations”.
But they warned of the “imminent threat” of corporate oil drilling, adding that it would “pillage the ecosystem for potential profit”.
Harry and Mr Mangundu wrote: “Some things in life are best left undisturbed to carry out their purpose as a natural benefit. This is one of them.”
The pair highlighted a huge oil spill off California earlier this month and a fire on the ocean’s surface of the Gulf of Mexico in July after a gas leak from an unerwater pipeline.
Harry and Mr Mangundu wrote: “There is no way to repair the damage from these kinds of mistakes.
“Drilling is an outdated gamble that reaps disastrous consequences for many, and incredible riches for a powerful few.
“It represents a continued investment in fossil fuels instead of renewable energies.
In their joint article, the pair urged others to get behind their campaign.
They said: “To protect the Okavango River Basin, we call on the world to stand in solidarity with us, our allies and local communities in advocating a full moratorium on oil and gas development in the region. “
Harry and Mr Mangundu added: “Now, the choice is simple: Either we honor our natural and life-sustaining ecosystems, preserving them for generations to come, or we exploit them on a path to permanent destruction.
“Will you stand with us?”
Harry has regularly spoken out about the environment and climate change.
He has also launched a sustainable travel initiative called Travalyst.
However he has been previously criticised over his use of private jets.
Harry’s campaign call to protect the Okavango River Basin comes ahead of Prince William’s Earthshot Prize awards ceremony on Sunday.
The Duke of Cambridge’s £50 million initiative aims to find solutions to the planet’s problems throughout the next decade.
The winners in the five categories this year will each receive £1 million to develop their projects after being chosen by a judging panel.
William and Kate are attending the star-studded awards ceremony, hosted by Clara Amfo and Dermot O’Leary, at Alexandra Palace in London.
In an interview with BBC Newscast which aired today, William said: “The prize itself will stimulate solutions and action that a lot of people haven’t necessarily produced yet, and so I’m hoping, you know, the prize will galvanise a lot of people in positions of responsibility to, you know, go further, bigger and actually start to deliver.”
Members of the Royal Family including the Queen, Prince Charles, the Duchess of Cornwall and the Duke and Duchess of Cambridge are also set to attend the Cop26 climate change talks in Glasgow which start at the end of the month.