Thousands of people are expected to take part in an Extinction Rebellion march at Glastonbury Festival before attempting to create the largest human sculpture of an hourglass.
The event, set up by festival organisers alongside the Green Fields, Greenpeace and Extinction Rebellion, begins at the Park Stage at 4pm.
Guest speakers will “make a stand for our planet”, organisers say, before crowds march to the Stone Circle in the King’s Meadow area of the 900-acre site.
People will then attempt to form the largest human sculpture of an hourglass to symbolise extinction.
Climate change and the environment is at the centre of this year’s Glastonbury Festival, with several talks and debates planned across the site.
The festival has banned single-use plastic bottles and urged those attending to bring their own re-usable bottle that can be re-filled for free.
Campers have been urged to bring sturdy tents and take them home, with the festival seeing an 81% reduction in abandoned tents in 2017 from previous years.
All cups, plates and cutlery at the festival are biodegradable and waste is hand-sorted to ensure as much as possible is processed by the on-site recycling centre.
Emily Eavis previously said: “This is a chance for everybody at the festival who feels passionately about protecting our planet and future generations to be part of a collective moment, before the main stages open up on the Friday.
“Everyone is invited to join in and listen to some inspiring speakers and send out a message to the world that this is a climate emergency and we need to act now.”
Liz Elliot, co-ordinator of the Green Fields, added: “We want to get across the message that we’ve not got long before our climate changes irreversibly.
“Time is incredibly short, but it has not quite run out yet. In fact, it feels like we are at an exciting turning point.
“Carrying on as we are now – living in this unsustainable way – is simply unacceptable.
“But if we can all make even small adjustments to the way we live our daily lives, these little ripples together will become powerful waves of change.”
Gates to the festival in Pilton, Somerset, opened at 8am on Wednesday morning with Michael Eavis telling those queuing: “Welcome to Worthy Farm.”
They were greeted by cloudy and damp weather, but sunshine and temperatures of up to 23C emerged in the afternoon.
Many attendees lay down and sunbathed, while others enjoyed ice creams and regular stops to the WaterAid water kiosks to refill their containers.
Music does not officially begin until Friday, though some performances take place on Wednesday and Thursday.
This included a silent disco by Fatboy Slim, aka Norman Cook, following the premiere of Ibiza: The Silent Movie with Julien Temple and Michael Eavis.
Stormzy, The Killers and The Cure will headline the event, which is the largest greenfield music and performing arts festival in the world.
Standard tickets for this year’s event sold out in just 36 minutes.