Environmental campaigner Jon Dee has remembered his 30-year friendship with Olivia Newton-John following the death of the singer-turned-activist on August 8.
Mr Dee worked closely with Newton-John on a range of environment and wildlife projects, including co-founding the National Tree Day and One Tree Per Child initiatives.
"Olivia co-founded One Tree Per Child with me in 2013. It is now planting trees in 10 countries. We also started National Tree Day together and fronted it for the planting of its first 10 million trees," said the Katoomba resident.
Mr Dee had a simple response to the many people who asked him over the years if the Grease star was as nice in person as they hoped she was.
"She definitely was," he said. "She had a heart of gold and her work for the environment and wildlife made a really big difference. She was a truly great Australian who made a real difference with her life."
Mr Dee said he hoped the international star would be remembered for her environmental work as much as she is for her singing and acting career.
"I want to make sure that people know about the wonderful things that Olivia did for the environment and wildlife," he said.
"Olivia wanted to see as many children as possible planting trees. That is why she and I started the National Tree Day [in 1996] and One Tree Per Child initiatives.
"Olivia's passion for trees and wildlife led to the planting of millions of trees here and overseas. She also saved millions of trees through her work against the logging of old growth forests."
Final message from Olivia
Mr Dee wrote Newton-John a letter before she died, reminding her of the many things she had done to protect the planet
"Her response was her last written message to me," he said. "It was short and sweet but it meant the world to me: 'I am so very proud of what we have achieved'."
With many Australians understandably sad about Newton-John's death, Mr Dee urged people to remember her by planting a tree with a child.
"In Greater Shepparton alone, we have planted over 100,000 trees with One Tree Per Child. In the British city of Bristol, kids have planted over 75,000 trees as part of One Tree Per Child. Olivia played a critical role in getting that all to happen," he said.
The initiative has now planted trees in South Sudan, Australia, the USA, Britain, Colombia, Kenya, Mali, the Netherlands, Ireland and Germany.
Mr Dee's first daughter is named Estelle Olivia Dee. He said the Grammy winner was a "lovely presence in my daughter's life and she was a loving mentor for her".
"Olivia was a wonderful and kind person. She lived her life true to her values and she did lots of good things for people and the planet. She represented the very best that an Australian can be. Like all of us... I will really miss her."