The 16-year-old environmental activist made her musical debut on a track called 'The 1975' - an eponymous title given to the instrumental song which opens the band's two albums 'Notes on a Conditional Form' and 'A Brief Inquiry Into Online Relationships' - which sees Greta read an essay over minimal orchestral backing.
And the 30-year-old singer has revealed they are planning to get together in the future because she is “one of the only people” who inspire him and his bandmates.
He told the Daily Star newspaper's Wired column: "I'm sure there will be moment where we get together ... she is one of the only people that inspires us."
On one part of the song, she says: "We have to acknowledge that the older generations have failed. All political movements in their present form have failed. But homo sapiens have not yet failed. Yes, we are failing, but there is still time to turn everything around.
"We are facing a disaster of unspoken sufferings for enormous amounts of people. And now is not the time for speaking politely or focusing on what we can or cannot say. Now is the time to speak clearly.
"So, everyone out there, it is now time for civil disobedience. It is time to rebel."
Money made from the track is being donated to campaign group Extinction Rebellion at Greta's request.
Meanwhile, the 'Chocolate' hitmakers' record label Dirty Hit have been taking measures to reduce their carbon footprint.
The band's manager and label CEO, Jamie Oborne, recently revealed his office phased out all single-use plastic, will no longer produce plastic products including CD jewel cases and are working to minimise the impact of vinyl production.
He said: "Rather than ignoring that it's a pollutant, we're minimising it by only doing lightweight vinyl from now on.
"That isn't very trendy, but one heavyweight LP is the equivalent of making two or three [standard thickness LPs]."
The label's CDs and vinyl are contained in paper packaging and not wrapped in non-degradable shrink wrap and they are planning to integrate a biodegradable shrink wrap in the future.
The 1975's next merchandise is also environmentally friendly, with unsold previous collections repurposed into new pieces of memorabilia.