Image copyright Matthew Horwood/Getty Images

Some of Wales' biggest emitters of greenhouse gases have been urged to join together to help tackle climate change.

More than 300 businesses, public sector bodies and community leaders are meeting at a conference in Cardiff.

Extinction Rebellion campaigners have also been invited by the Welsh Government to share their ideas.

Environment minister Lesley Griffiths said she hoped for a "collective response" to cut emissions.

Wales is set to put a new target into law next year for a 95% reduction in greenhouse gases from 1990 levels by 2050.

It follows advice by experts at the Committee on Climate Change, who said it would be an appropriate contribution to the UK hitting a so-called net zero target by the same year.

Net zero means effectively eliminating greenhouse gases from our economy and way of life - not pumping out any more than we can absorb back from the atmosphere through trees or new technologies.

But Ms Griffiths cast doubt on the feasibility of calls from within her own party for swifter action.

Speaking to reporters ahead of the conference she was asked about a motion passed at the UK Labour party conference, backing a net zero target by 2030.

"I personally at the moment don't think it is (doable)," she said.

"The UK Committee on Climate Change are telling me that Wales can't even do it by 2050, at the current time - and that's why were set a target of 95% reduction in emissions by 2050."

"However we've said that we have the ambition to be net zero."

Media playback is unsupported on your device Media caption The 10-year-old girl inspired by Greta to save the planet

The inaugural Climate Change Conference is being hosted by the Welsh Government' after it declared a climate emergency in April. It is set to become an annual event.

Ministers say it will help inform Wales' response to future UN summits on global warming and "an ambitious All Wales Delivery Plan in 2021".

But business leaders said companies needed more support and advice on the issue.

Ben Francis, policy chairman of the Federation of Small Business in Wales, said small firms were taking really innovative steps to reduce their carbon impact - from donating off-cut fabrics to colleges to giving staff reusable drinks bottles to cut down on single-use plastics.

But he said businesses also needed advice and guidance on where to go when making big decisions on environmental issues, such as buying a vehicle or looking for premises.

"Having declared a 'climate crisis' governments now need to engage business to explain what will be done differently as a result of that in a conversation which not just about obligation but also opportunity for businesses and the wider Welsh economy," he added.

Deeside-based supermarket chain Iceland agreed there could be more advice, with carrots as well as sticks - including tax breaks for innovation around food waste.

It said as well as eliminating palm oil from the shelves it had a pledge to eliminate plastic from its own label packaging by 2023 - and wants other retailers to follows its lead.

"Ultimately our customers are telling us they want us to do these things," said managing director Richard Walker. "Eighty per cent of them said we should lead on these activities but we're also looking at reducing our carbon and food waste."

Image caption Extinction Rebellion protestors dressed in red outside Cardiff City Hall

As well as attending the conference, Extinction Rebellion activists intend to stage a demonstration outside it.

During the day extreme endurance athlete and former Welsh rugby player Richard Parks will be announced as a climate change ambassador.

He said he was excited to be working with the Welsh Government in the run up to the UN COP 26 summit on climate change in Glasgow next year.

Greenhouse gas emissions in Wales CO2 totals and forecast, 1990-2050

"From Antarctica to here in Wales, I have undertaken expeditions across the globe," he said.

"Having experienced first-hand the impact climate change is having on our world, now is a critical time to protect our planet for our children."

Image copyright Richard Parks Image caption Richard Parks says his "expeditions across the globe" mean he has seen climate change first-hand

When asked on BBC Radio Wales' Breakfast with Claire Summers what changes he had made to help the environment, he said: "It's a number of things. The decision that we make about where we shop, around the clothes that I purchase, the choices I make around recyclable containers.

"These all might seem obvious and trivial but they're a way we can all become part of the solution and we can all become accountable.

"One of the things my family and I have done over the last few years is make a conscious decision not to use the car on weekends. Sometimes we have to, we all lead normal lives… I've made a conscious decision in the last five to 10 years to use public transport."

Siân Stephen, of Extinction Rebellion said: "We're delighted that the government has taken the move to hold this conference, bringing together the business sector and third sector to discuss ways of decarbonising."