The Earthshot Prize was created by Prince William and The Royal Foundation and "aims to find and reward inspiring and innovative solutions, from around the world, to the environmental challenges facing our planet".
The inaugural awards ceremony is occurring tonight at London's Alexandra Palace. Five £1 million pound prizes, based on five Earthshot goals, are to be awarded each year for the next 10 years.
In his caption, Charles went on to emphasise the importance of finding innovative solutions to environmental problems, saying: "As a world, we need to come together to inspire, reimagine and build the sustainable future we so desperately need."
The royal also gave a shout out to his own Terra Carta and Sustainable Markets initiatives, which he said will work "in parallel" with his son's Earthshot program to "transition the global economy onto a more sustainable trajectory".
"Together, with all those who join us, we have a real opportunity to deliver a brighter future for humanity while restoring harmony between Nature, People and Planet."
Prince Charles has long been a vocal advocate for the environment. Just recently, the heir to the throne called upon Australian Prime Minister, Scott Morrison, to attend the UN's climate change conference, occurring from Sunday 31st October to Friday 12th November.
During an interview with the BBC, Prince Charles was told that Morrison remained on the fence about attending.
"Is that what he says?" Charles asked climate editor Justin Rowlatt.
When asked what he would say to leaders about why they should attend the conference, Charles emphasised that this meeting is a "last chance saloon", explaining that if change doesn't happen now, it will be "almost impossible to catch up".
Upon being pressed about his advice to the Australian government with regards to their inaction when it comes to climate change, Prince Charles gave his reply.
"I mean you gently try to suggest there may be other ways of doing things, in my case anyway, otherwise you lot (the media) accuse me of interfering and meddling, don't you?"