Council leaders have been accused of missing a golden opportunity to promote their commitment to the green agenda by failing to work out the carbon footprint of Birmingham’s first climate change festival.

West Midlands Friends of the Earth said the city council would be unable to plan properly to reduce environmental damage in future if it did not have an accurate understanding of carbon emissions created by today’s leisure events.

The festival, organised by the council and CABE, the Commission for Architecture and the Built Environment, was attended by thousands of visitors and ran from May 31 to June 8. It was billed as a world first by the council.

A steel electricity pylon constructed in Victoria Square outside the Council House was described by organisers as the centrepiece of the event and a “reminder that our consumption of power is an issue, but so too is distribution”.

The festival website added: “The climate change festival has been designed to make the (invisible) carbon emissions visible, and the idea lies at the heart of our problem with energy: we are rarely conscious of how much we use.”

Friends of the Earth spokesman Chris Crean said: “Clearly, the pylon had to be constructed and brought to Birmingham, then dismantled and taken away. That will have had an impact on carbon emissions, along with other activities at the festival.

“The important thing is that the council reduces carbon output next year, but you can’t do that if you don’t know the footprint this year.

“This is a lesson that has to be learned from what was an ambitious and imaginative event.”

Mr Crean is urging the council to routinely calculate the carbon footprints of major events – including this year’s Conservative Conference in Birmingham, football matches at Villa Park and St Andrew’s, ArtsFest and the Clothes Show at the NEC.

He said: “We have to start working this out today in order to make sure we have a true carbon reduction strategy for the city.”

Deputy council leader Paul Tilsley, who has cabinet responsibility for sustainability, denied that organisers had forgotten to work out CO2 emissions.

He insisted that a carbon footprint calculation would be part of a “post-event evaluation exercise by CABE”.

Coun Tilsley (Lib Dem Sheldon) added: “CABE are the experts in this field and you can only do these things in hindsight.

“We know the list of activities that were involved in the festival and we can get a reasonable idea of the carbon footprint. We will then have a baseline, a framework, which we can work against when we have a similar event in future.”

A council spokesman added: “While it is impossible to say exactly how much carbon was emitted during the festival, we can say with certainty that over the long-term it will have saved infinitely far more than it produced.

“Not only did the event put the issue of climate change at the forefront of the political and public agenda, but thousands of residents took a direct part in the week.”

Achievements at the festival, according to the council, included:

* 1,500 people signed pledges to cut their individual footprint by 100kg over the next 12 months

* 2,000 plastic carrier bags exchanged for long-life green alternatives

* nearly 100 individual items of IT equipment dropped off for recycling

* 1,000 schoolchildren visited the event to learn about climate change issues

* all official festival material was produced on recycled paper.