The stars were out on the green carpet on Wednesday night at Prince William's glittering Earthshot Prize Awards.
The Prince of Wales attended the Earthshot Prize Impact Assembly at Pier 3, part of the three-day Earthshot summit in Rio, to see prizes handed out to groundbreaking environmental initiatives, a cause close to his heart.
The event brought together government officials, indigenous leaders and youth advocates to share inspiring Earthshot stories from the past year, and highlighted investments which are helping finalists scale up their environmental solutions.
Global superstars Shawn Mendes and Kylie Minogue answered the heir to the throne's call to headline the awards show in the vibrant Brazilian city of Rio de Janeiro.
Dazzling Kylie, 57, said she was wearing a Stella McCartney 'rewear' to the event.
Caught on a live Sky News broadcast, she also praised Prince William's Earthshot prize as 'amazing people doing incredible things'.
In an impassioned speech on Wednesday night, William said: 'I understand that some might feel discouraged in these uncertain times. I understand that there is still so much to be done.
'But this is no time for complacency, and the optimism I felt in 2020 [when he set up the awards], remains ardent today.
'Because our finalists are a shining example of how we can build stronger economies, design healthier cities, and create better jobs for the next generation.'
He continued: 'We can support the dreamers and innovators who work tirelessly to build a more sustainable world. We can protect our beautiful planet for all life that calls it home.
'The choices we make during this decade will define us… but more importantly, they will define the lives of young people. The future belongs to them.
'They are the ones who will inherit the planet we are fighting to protect. They are the ones who will continue to drive our momentum forwards.'
Re.green was awarded The Earthshot Prize to Protect and Restore Nature for 'leading a global movement to restore Brazil's lost Atlantic Forest, combining cutting-edge technology, ecological science and social impact'.
Soon after, Brazilian footballing legend Cafu announced The High Seas Treaty, led by The High Seas Alliance, as the winners of The Earthshot Prize to Revive Our Oceans.
The Prize to Build a Waste-Free World went to Lagos Fashion Week, for its work on sustainable fashion, before Friendship secured the Fix Our Climate award.
And to top it all off, the city of Bogota was handed The Earthshot Prize to Clean Our Air after the Colombian city reduced its air pollution by a whopping 24 per cent.
William, 43, arrived at the Museum of Tomorrow wearing a black tie suit by Tom Ford.
Appropriately, given the environmental theme of the awards, it was also a rewear.
On arrival he was met by Luciano Huck, presenter of the awards, who invited him to view local samba dancers and carnival artists.
He then walked the green carpet and met musical artists performing in the Awards including Anitta and Seu Jorge as well as Mendes and Minogue.
Posing for photographs on the green carpet, Mendes thanked Prince William for a birthday cake he had arranged for his British mother, Karen, whose birthday was on Sunday, when they met earlier in the day. She was 'overjoyed' apparently.
He was also introduced to British Prime Minster Sir Keir Starmer and Jacinda Ardern, former PM of New Zealand, Stephanie Al- Qaq, British Ambassador, and Marina Silva, Environment Minister, Brazil.
Following tradition, William was offered the flag of the Samba School, Beja-Flor, by performer Selminha Sorriso and kissed it, before joining his hands in a gesture of thanks for the warm welcome.
He was escorted by Earthshot CEO Jason Knauf and awards presenter Luciano Huck and stopped to chat to a group of 100 local young people invited to attend.
Among them was 13-year-old Giovanna Castro who had come with dad Henrique from Iguaba Grande, 130km away, to see William, bringing her drawing of him and Kate on their wedding day.
The Prince stopped to chat to her and her father for several minutes and appeared touched by her gift.
She said ahead of his arrival: 'I really love the royal family, I really appreciate them. It's a very rare opportunity to meet the Prince.'
After walking the green carpet, William headed upstairs to meet Prime Minister Sir Keir Starmer, former New Zealand Prime Minister Jacinda Ardern, Britain's Ambassador to Brazil Stephanie Al-Qaq and Brazilian environment minister Marina Silva.
The Prince then took his seat inside the ceremony, which opened to more music and dancing from Beja Flor and a performance by Anitta, who sang the classic Brazilian hit Mas Que Nada, before duetting with Gilberto Gil with a version of the Girl from Ipanema.
Shawn Mendes performed his song Youth, while Seu Jorge played the David Bowie classic Heroes.
William was later spotted singing along as Kylie closed the show with a high-energy medley of her hits Padam, Can't get you out of My Head and a cover of Celebration by Kool and the Gang.
After the ceremony, he thanked Kylie, Gilberto Gil and Seu Jorge for performing.
'Thank you so much, honestly, the whole thing was fantastic,' the Prince told Kylie, commenting on the fact that 'everyone was up and dancing!'
The singer congratulated him on the ceremony, saying she had watched from her dressing room and praising 'the energy from the crowd'.
William then appeared to suggest Kylie could perform at another Earthshot Prize ceremony in future.
'It's a deal,' she told him.
Shaking hands with awards presenter Sebastian Vettel, he gestured to two-times World Cup winner Cafu, who was standing next to him, and joked, 'We played football together yesterday and I beat him.'
William was also invited to return to Brazil by indigenous environmental activist Txai Surui, who said she wanted him to see the work being done to protect her ancestral land in the Amazon.
The Prince also joined the five winners backstage.
'Congratulations! I hope you were all surprised?' he asked them.
'When I saw you earlier I had to keep a straight face - I knew what was happening. Did you get to enjoy it or were you just a bag of nerves? You should be so proud of yourselves.
'All the finalists are winners, but you guys, the little things that you do just tipped it over the edge.'
The Prince said this year's cohort had been 'so hard to judge,' adding: 'It took three and a half hours of just going round and round. A lot of really good debate happened, but you guys were the clear winners in the end.'
William also spoke to Ed Miliband, Secretary of State for Energy and Climate Change and Mayor of London Sadiq Khan, along with Earthshot Prize Council Members Wanjira Mathai, Nemonte Nenquimo, Naoko Yamazaki and Hindou Ibrahim.
Earlier, the Prince said he wants to 'provide leadership and vision that there's good things to come' as he prepared for the awards ceremony.
During a 'fireside chat' with the event's anchor, the CNN anchor Christiane Amanpour, William spoke of being positive for his own children and young people around the world.
He said: 'You have to provide a leadership and a vision that there's good things to come and it's not all negative.
'And for my children, particularly, knowing that the planet's going to be in a better, healthier state because of the people in this room is something I love to tell them when they go to bed – it's going to be great, your future is going to be as bright as futures gone by and that's a really important message for all us to hear.'
He added: 'A world without hope and a world without positivity is a pretty depressing place.'
Asked about his recent references to making 'changes' to the monarchy, and about 'a lot of change in your own family – where do you see the change, what do you think needs to happen?'
William replied: 'I think the Earthshot Prize is a classic example of change, rather than talking about it, we're doing it. Change will come by backing them, not by what I do.
'It's really important that the next generation believe that change is coming.'
William travelled to the event on the Earthshot Prize Tram down the specially-created 'Earthshot Boulevard', where he was met by Earthshot chief executive Jason Knauf, who showed him a timeline of the Prize's 5 years to date and gave an introductory speech to delegates, declaring: 'Our 2025 finalists are transforming our world.
'Our success is inevitable and our momentum is unstoppable.' Ardern described the past five year's finalists as 'ambassadors of optimism'.
The panel discussions also included Barbados's Prime Minister Mia Mottley, Brazil's environment minister Marina Silva and Jacinda Ardern, the former prime minister of New Zealand and Earthshot board trustee.
During her discussion onstage, Mottley said of global climate activism: 'We're going in the right direction but not fast enough. It takes cash to cure and cash to build.'
Several finalists also took to the stage to announce new deals for their initiatives, including Adam Root, the founder and CEO of Matter, whose washing machine filters remove microfibres from wastewater.
Root told the assembly he has secured a multi-million pound deal with Ikea to scale up Matter's technology internationally.
Speaking to the media after the event, Ardern said: 'This prize is making a difference. It's not just an award, it's a catalyst for change.'
Asked if the Prize might travel to New Zealand in the next five years, she said: 'The goal of the Eartshot Prize is to reach every corner of the world.
'There's no nepotism on the board! I advocate for the region, and the region advocates very well for itself.'
This evening, William will be joined at the Earthshot Awards by the Prime Minister, Sir Keir Starmer, where he will give a landmark speech at the Museum of Tomorrow, hailing the finalists' work to create solutions to some of the world's biggest environmental challenges.
It comes after the prince yesterday received a gift of three matching football shirts for his children ahead of the Earthshot Prize awards.
The Prince of Wales visited the iconic Maracanã Stadium - Brazil 's 'temple of football' - for a Generation Earthshot event with 75 young people from across the region, which aims to help them to become future climate leaders.
Football fan William was presented with his own hand-signed football shirt from former Brazilian player Cafu.
The future king told the player: 'It's an honour. We've all seen how your feet work.'
William, a keen Aston Villa supporter, also received three football tops for Prince George, 12, Princess Charlotte, 10, and Prince Louis, seven, who have remained at home after moving into their 'forever home', Forest Lodge in Windsor, last week.
The Fluminese Generation Earthshot shirts featured green, red and white stripes and were personalised with each of the children's names - though, rather awkwardly, Louis's was misspelt as 'Loui'.
The Wales children will no doubt be thrilled with their father's gifts from abroad, as all three are known to be huge football fans.
Prince George, for example, appears to be following in his father's footsteps as a fan of Aston Villa, and the pair have attended several matches together.
During the engagement, William and Cafu later teamed up with some kids to play against each other on the pitch, before William ran drills with the children and took a successful penalty kick.
William also took part in discussions with young people from Brazil, South Africa and Asia who are meeting in Rio to develop skills to become climate leaders under his Generation Earthshot program.
'We need a bit more courage. We need you guys to keep that energy going. If we wait for good leaders we are going to wait a long time. You guys are my hope,' William said after he questioned young people on the problems their communities face and the projects they are working on to help the planet.
