Islington's eco chief refused to answer questions relating to the new incinerator being built in north London during an interview about the council's eco festival – held to reduce CO2 emissions.

The council's festival, Islington Together: Let’s talk about a greener future, which launched this week, is organised in the run-up to the United Nations Climate Change Conference (COP26) to encourage residents and businesses in Islington to reduce their carbon emissions.

But in an interview to discuss green issues, Cllr Rowena Champion would not address questions around the controversial rebuild of the Edmonton incinerator.

Cllr Champion told the Gazette the climate emergency has plunged us into an "existential crisis".

But while the latest figures available indicate Islington's entire annual output is 680,000 tonnes of CO2 each year, some estimate the incinerator will emit as much as 700,000 tonnes if it runs at full capacity.

Cllr Champion and Cllr Satnam Gill represent Islington and sit with 12 councillors from other local authorities on the board of the North London Waste Authority which is pushing forward plans to rebuild the incinerator at a cost of £683m – despite opposition from campaigners who are calling for a rethink, amid reports from the Mayor of London that it is surplus to London's waste requirements.

Cllr Champion told this paper she was "not happy" discussing the incinerator and that she "would like to have thought about it a little bit more".

"If you want to talk about the incinerator I think we should do that somewhere else, because it's pretty complicated, and at the moment, I think it is very absolutely certain to say we will have a lot of waste to get rid of in the world for sometime to come," she said.

"Landfill is not good, we know that. The NLWA is run by seven local authorities, all of whom are highly accountable to local people and the incinerator will be of the highest quality it can be."

The Gazette requested a follow-up interview but instead, more than a week later, received a statement as it was going to press.

Cllr Champion had already refused to be pushed on campaigners' questions about the incinerator at a public meeting held in March, instead saying that she would respond by email – but only replied this week after being prompted by the Gazette.

The questions included whether the case had been considered for removing recyclables and anaerobic waste from black bags before incineration, which would drastically alter the incinerator capacity needed.

The capacity is currently set at 700,000 tonnes a year – more than needed if recycling targets are met – and the reason it might now have to truck in waste from elsewhere in London.

Only one bidder is left in the race to win the contract to rebuild the incinerator, raising questions about the tendering process.

When pushed about Islington's air pollution and CO2 emissions aims, in light of the the effect that burning Islington's waste might have on Edmonton's population, Cllr Champion said: "The incinerator will be of the highest standards around."

She cited carbon capture storage – "once it becomes available" – as a mitigating factor.

Moving on to the eco festival, which runs until October 29, she said: "There's really quite an interesting range of topics that people can take part in.

"In my own ward we are going to do a walk between green spaces, and prepare some tree pits and as people walk in between the spaces we are going to get them to plant some bulbs in the tree pits, so that come spring we have a nice corridor, because of biodiversity."

Details can be found via islingtonlife.london, the council's in-house magazine.

Following the interview, the council provided a statement in which Cllr Champion claims the energy-from-waste incinerator – which will produce heat and hot water for 50,000 homes – is the "most environmentally-friendly way to deal with the non-recyclable waste that north London is expected to produce in the future".

She added: "If the situation changes, and the amount of waste is significantly less than expected, it can run at reduced capacity, without the need to import waste from outside north London boroughs, so north London is able to manage its own waste in line with the mayor’s objectives."

The Gazette was told to contact the NLWA about any "technical questions".

The NLWA has said claims about emissions from the incinerator are "misleading" but has not provided its own figure. It has said a new incinerator would still be needed even if a pre-sorting process is in place.