But will they enact change? That's the question Greta, and millions of others are left pondering as we anxiously watch the conference play out before us.
Speaking to BBC this week, Scotland's World Wildlife Fund director Lang Banks explained that Greta's concerns were absolutely not without basis: "The world leaders have not stepped up to the plate. They have an opportunity now to turn their warm words we've heard today into action," he explained.
To add to her appeal, Thunberg has joined forces with several other young activists from around the world including Uganda's Vanessa Nakate, the Phillipines' Mitzi Jonelle Tan and Poland's Dominika Lasota.
The four activists have started a petition and written an open letter for world leaders. Calling the progress they've made so far a "climate betrayal", the letter demands the outcomes of COP26 to include sticking to the goal of keeping the median temperature rise at 1.5°C alive, to put an end creative carbon accounting, and to deliver the US$100 billion promised to the world's most vulnerable countries.
Already the emergency appeal has garnered more than 1.6 million signatures (at the time of writing). You can read it in full and sign it here.
In a similar vein to Greta, documentary maker and global treasure David Attenborough was one of the climate activists invited to address the leaders at COP26.
In his emotional speech directed solely at those in the room this week, he reiterated that the future of climate change rests on this conference.
"The people alive now are the generation to come, [and] will look at this conference and consider one thing: Did that number stop rising and start to drop as a result of commitments made here?"
He added: "There's every reason to believe that the answer can be yes."
The Our Planet documentary maker added: "If working apart, we are a force powerful enough to destabilise our planet. Surely working together, we are powerful enough to save it. In my lifetime, I've witnessed a terrible decline."
"In your lifetimes, you could and should witness a wonderful recovery. That desperate hope ladies and gentleman, delegates, excellencies, is why the world is looking to you and why you are here."
Let's hope they listen.