Coldplay: Are the band's fans as eco-conscious as them?

Coldplay have entertained Cardiff for the past two nights as their "eco-friendly" tour hit the Welsh capital.

But how environmentally friendly are the fans of the band and what impact do these tours have on the city?

More than 100,000 fans descended on the capital to see the band perform, including 23-year-old Sarah Owens, who went to celebrate her birthday.

She said it was amazing to see the gig was environmentally friendly.

"Before the gig they played a film showing how the ticket sales went to good causes like saving the ocean and planting trees.

"Inside all the cups were paper, there was no plastic, the confetti as well, it was all paper - including wristbands."

She added that Coldplay's sustainability message was important and was really making a difference.

Samantha Thomas is a senior cleansing officer for Cardiff council and it is her job to make sure the streets of Cardiff are clean during and following events.

She has a team of eight people who clean up the entire city after a gig like Coldplay and they have a system that means they know exactly when to go in and clean.

"There are two different ways that we do it, so we work very closely with the Highways Department to make sure that the teams can come in when the streets are clear.

"So this evening [Tuesday] the main act is due to go on around nine-ish, so we know most people would be in the stadium around 8pm, so the teams are ready to go once highways tells us the roads are clear enough to operate, and we only work within the road closures."

She said the teams then go in and do a full sweep, empty the bins and remove all the waste so when people come out of the concert everything is relatively clean.

"When the event finishes, and everyone leaves, a different team then comes back in at 11pm and does a full clean again, and they will be done around three or four in the morning."

Ms Thomas said this team operated from the outside in, so they would work on the outer town and progress into the pedestrianised shopping areas such as Queen Street and the Hayes.

Finally they clean Caroline Street - also known as Chippy Lane - where many of Cardiff's takeaways are based and which tends to be more strewn with litter.

"We look at the dynamics, we look at the genre of music or the sporting event," said Ms Thomas.

"We look at how many people, the capacity, so we know exactly what resource we need to make sure we can get the city clean for the next day."

Ms Thomas added when it is a sell-out rugby event, like the Six Nations, they are aware people will be out drinking or hanging around the streets and the stadium, so each event is judged differently.

"You need to be more aware and conscious of the people, making sure that we clean up around and within the areas that are going to be more populated when the gig is over."

Ms Thomas said she was quite shocked when she came in to do her checks.

"I was surprised at how clean it was. Unbelievable, in comparison to more recent events that we've had in the city, it is very clean.

"It's been a lovely atmosphere and not that dirty, which is nice for the teams."

So how much waste does an event like this generate and what happens to it?

"We'd be looking at around three to four tonnes, but that's from start to finish," Ms Thomas said.

She added what happens to the waste depends on where it has come from.

If it is street sweeping, it is contaminated so this goes to a waste transfer station and sent onto to Viridor for incineration.

This means waste is burned at very high temperatures creating two by-products: Bottom ash - materials that do not burn - and fly ash - residue that is collected through the air clean up technology.

Both of these by-products are recycled with zero waste disposed in landfill.

The commercial waste is separated and then recycled.

"Well as I said the audiences and the music genres for each gig differs, so we are thinking the next one will be very different."

So, the three principles that Coldplay are being guided by on this tour of reduce, reinvent, restore can be seen across the city of Cardiff, with their fans seemingly just as environmentally friendly as the band, but will other artists follow suit?