Japanese singer Ayaka urged people to do what they could. "We can start helping by doing something small," she said.
"I started to carry my own eco-bag so I don't have to use plastic grocery bags, and use my own chopsticks instead of disposable ones."
...10,000 fans packed the main arena at Tokyo's Makuhari Messe complex to hear Linkin Park, R&B diva Rihanna and a multitude of Japanese artists.
...Some fans conceded, however, that they were more interested in the music than the message.
"I came here for Linkin Park and Linkin Park only," Masato Nakajima said.
"But I think this is a good event. If Linkin Park tells me to go eco-friendly, I will do it. Absolutely," he added.
Would he listen to the self-obsessed, god complex suffering Madonna? I mean, she'll be disappointed if he doesn't:
Madonna's carbon footprint is dwarfed only by her ego - she has vowed that she will 'speak to the planet' at Wembley.
Not all rock stars are so self-obsessed; some of them are seemingly intelligent:
Roger Daltrey, of the Who, said another concert would simply waste fuel; Bob Geldof, who helped to organise Live Aid and Live 8, said people were already aware of the greenhouse effect; while Matt Bellamy, front man of the rock band Muse, labelled it "private jets for climate change".