She also reflected on the "deep and abiding affection" and happy memories she and the late Duke of Edinburgh shared of Scotland as she formally opened the new session of the Scottish Parliament.
Accompanied by the Prince of Wales and the Duchess of Cornwall - known as the Duke and Duchess of Rothesay in Scotland - the Queen told MSPs that as the country emerges from the "adverse and uncertain times" of the pandemic, there was an opportunity for "hope and optimism".
The Queen said: "The beginning of a new session is a time for renewal and fresh thinking, providing an opportunity to look to the future and our future generations.
"Next month, I will be attending Cop26 events in Glasgow.
"The eyes of the world will be on the United Kingdom - and Scotland in particular - as leaders come together to address the challenges of climate change.
"There is a key role for the Scottish Parliament, as with all parliaments, to help create a better, healthier future for us all, and to engage with the people they represent - especially our young people."
Speaking at Holyrood for the first time since the Philip's death, she added: "Today is also a day when we can celebrate those who have made an extraordinary contribution to the lives of other people in Scotland, locally or nationally during the Covid-19 pandemic.
"I have spoken before of my deep and abiding affection for this wonderful country and of the many happy memories Prince Philip and I always held of our time here.
"It is often said that it is the people that make a place. And there are few places where this is truer than in Scotland. As we have seen in recent times.”
Responding to the Queen's speech, the First Minister offered the parliament's "deep sympathy and shared sorrow at your loss" and thanked her for being a "steadfast friend of our Parliament since its establishment in 1999".
Ms Sturgeon continued: "As we battle through the storm of a global pandemic, hope and the hankering for change is perhaps felt more strongly by more people than at any time in our recent history.
"That gives this Parliament a momentous responsibility and a historic opportunity.
"Covid has been the biggest crisis to confront the world since the Second World War - it has caused pain and heartbreak, it has exposed and exacerbated the inequalities within our society.
"But it has also revealed humankind's boundless capacity for inventiveness, solidarity and love.
"And for those of us in public service, it has reminded us that with collective political will, changes that we might previously have thought impossible or just too difficult can indeed be achieved.”
The monarch, who has been on her annual break at Balmoral Castle in Aberdeenshire, met party and parliamentary leaders in the garden lobby ahead of the ceremony in the debating chamber.
Afterwards, the Queen, Charles and Camilla were due to meet Scots who have been recognised for their contribution to communities during the Covid-19 pandemic.