In a video message, she said many people hoped the "time for words has now moved to the time for action".
She urged them to act "for our children and our children's children" and "rise above the politics of the moment".
The Queen added she took "great pride" in how her "dear late husband" Prince Philip promoted environmental issues.
The 95-year-old monarch had been scheduled to attend the United Nations conference in Glasgow. But she pre-recorded her address last week at Windsor Castle after being advised to rest following medical checks.
The Prince of Wales and Duke of Cambridge are both attending the COP26 conference, which is seen as a crucial gathering if temperature increases and climate changes are to be limited.
In her address, the Queen recalled how the "impact of the environment on human progress was a subject close to the heart" of the Duke of Edinburgh. She referred to his warning at a 1969 academic gathering of the dangers of failing to address pollution.
The Queen said: "It is a source of great pride to me that the leading role my husband played in encouraging people to protect our fragile planet, lives on through the work of our eldest son Charles and his eldest son William.
"I could not be more proud of them."
Even though not there in person, this was a surprisingly personal message from the Queen.
She mentions how the environment was a subject close to the heart of "my dear late husband" Prince Philip and says she "could not be more proud" that it was an interest sustained by her son Charles and grandson William.
She also seems to make reference to her own mortality: "None of us will live forever."
But there is also the authoritative voice of someone looking back after almost 70 years as head of state, telling world leaders to take the long view and "rise above the politics of the moment".
The Queen says "statesmanship" means serving the future rather than short-term political rewards.
She might be on the video screen but she was telling world leaders to focus on the big picture.
The Queen said she also drew "great comfort and inspiration from the relentless enthusiasm of people of all ages - especially the young - in calling for everyone to play their part".
She said: "In the coming days, the world has the chance to join in the shared objective of creating a safer, stabler future for our people and for the planet on which we depend.
"None of us underestimates the challenges ahead: but history has shown that when nations come together in common cause, there is always room for hope."