In the essay, which she recites over ambient music from the Manchester band, Thunberg calls for "civil disobedience" and says "it is time to rebel".

"There are no grey areas when it comes to survival," she adds on the track, which was released overnight.

Thunberg, 16, has become one of the leading voices in the climate debate.

She rose to prominence last year when she began skipping school to take part in protests.

The new track will not be a single in its own right - but will feature as the opening song on the band's album.

This is in keeping with the band's previous records, all three of which have opened with an ambient instrumental track entitled The 1975.

Thunberg's track will also take that title - but this will be the first album opener from the band to feature speech on top of the music.

Notes on a Conditional Form was recorded at the same time as The 1975's last album, A Brief Inquiry Into Online Relationships, which was released in November last year.

The album helped them win two Brit Awards earlier this year, further cementing their status as one of the biggest bands in the UK.

The music industry is still a major contributor to climate change. A report in the scientific journal The Conversation earlier this year suggested that, in the US alone, its greenhouse gas equivalents (GHGs) - a way of measuring emissions - has almost doubled since 1977.

The 1975 are currently on a world tour, and will play gigs in Italy, Korea, Romania, Singapore, Ukraine, Dubai and Australia in the coming weeks.

It is likely they will fly to many of those countries, despite air travel being a significant contributor to climate change.

Thunberg took a 32-hour train journey to speak at the World Economic Forum in Davos earlier this year, in order to avoid flying.

On the new track, Thunberg can be heard telling listeners: "We are right now at the beginning of a climate and ecological crisis. And we need to call it what it is: an emergency."

"Today we use about 100 million barrels of oil every single day," she continues. "There are no politics to change that. There are no rules to keep that oil in the ground, so we can no longer save the world by playing by the rules, because the rules have to be changed, everything needs to change, and it has to start today."

The essay is direct in its message but short on actual practical measures which she thinks should be put in place.

She does, however, say: "The main solution is so simple that even a small child can understand it. We have to stop our emissions of greenhouse gasses."

Thunberg became famous last year after she protested every day for three weeks during school hours by sitting outside the Riksdag (the Swedish parliament), calling on the government to reduce carbon emissions in line with the Paris Climate Agreement.

She gradually built up an online following and encouraged young people around the world to take part in protests.

Thunberg has since become a prominent political figure and has spoken at the European Parliament in Strasbourg and the UN's Katowice Climate Change Conference.