Music fans going to the Glastonbury Festival will be asked to make a difference to climate change by reducing their carbon footprint.
As well as eating organic food, washing in carbon neutral showers and using eco-friendly toilets, revellers will be invited to join the I Count campaign.
It shows people 16 steps that reduce their environmental impact, and aims to sign up 100,000 in three days.
More than 135,000 people will descend on the Somerset venue from 22-24 June.
Everybody arriving at the festival will be given a special wristband with the I Count slogan "We can stop climate chaos".
Festival organiser Michael Eavis explained: "We've put a lot of effort into focusing Glastonbury on the environment and climate change this year.
"We hope to see at least 100,000 new supporters sign up to the I Count campaign - and I'll be the first to put my name down."
The campaign is supported by the Stop Climate Chaos coalition of more than 50 organisations, as well as the three main causes supported by Glastonbury - Oxfam, Greenpeace and WaterAid.
Other green initiatives include supplying each festival-goer with their own roll of recycled toilet paper.
Among acts already confirmed to play include the Arctic Monkeys, The Who, Kaiser Chiefs and Dame Shirley Bassey, with the full-line expected to be announced soon.