The city council will not be seeking costs from a group of youth demonstrators who unwittingly caused a public stir by writing messages in chalk around Nelson.

The chalk slogans, including one on the Church Steps, appeared on Friday to promote a demonstration on Saturday in support of environmental causes. They triggered complaints from the public which prompted the council to have them removed.

City council network services executive manager Alec Louverdis said on Friday that the council had instructed contractors to remove the messages, which people thought had been done in paint. He said it was possible the council would look at recovering costs from the people who put them there.

Nelson Mayor Aldo Miccio said on Saturday the group would not be fined or charged for the chalk sign on the steps.

"I think it's fantastic that young kids are taking initiative to make a difference in the world we live in."

The group of young Nelsonians gathered in Trafalgar St on Saturday morning to demonstrate that local and national solutions to climate change exist.

The event was part a week-long, nationwide launch of the "100% Possible" campaign which aims to spread the message that moving New Zealand beyond fossil fuels is 100 per cent achievable. The event was being co-ordinated by climate change groups 350 Aotearoa and Generation Zero.

Councillor Kate Fulton, who was at Saturday's demonstration, said it was important that young people were allowed to have their say.

"Freedom of expression is very important. They didn't think they had done anything wrong."

Generation Zero Nelson co-ordinator Rachel Ward said the reaction surprised them but did not dampen spirits on the day. The group was sorry people might have got the wrong idea, and that the council supported the campaign.

Public response on Saturday had been very positive.

"A lot of people congratulated us for our efforts," Ms Ward said.

She said the message they aimed to get across was that there are alternatives to the use of fossil fuels in renewable energy sources such as solar, wind, hydro, tidal and geothermal.

Ms Ward also said the Government's plans to spend billions on new roads would be better spent on developing more walkways and cycleways and public transport options.

"We realise it's our future these decisions will impact on," she said.

- © Fairfax NZ News