They used to claim that climate change wasn’t happening.

Then they accepted that it was, but said it wasn’t down to humans.

Now we hardly hear from them.

The climate change deniers are in retreat.

Footage of oceans clogged and wildlife choked by our plastic waste have brought home to many of us the effect we’re having on the environment.

So have thermometers. The 20 hottest years on record have all occurred within the last 22. The natural cycle couldn’t cause such a sudden increase.

Now 78 per cent accept of British people accept what scientists have long been telling us – that we could be heading for a climate disaster and that human activity is responsible for it. Six years ago only 59 per cent did. The age of denial may be over. But it hasn’t translated into meaningful action. Amy Bray is worried.

“We are going to reach a tipping point when we won’t be able to reverse climate change,” she warns. “That makes me really, really frightened.”

However Amy, 17, is not just worrying about it. She is doing something. Long before the world had heard of Swedish teenage climate activist Greta Thunberg, the teenager from Matterdale had been working to get the message across about the catastrophe we are facing and the need to act now.

It could have been that the warnings of a teenager wouldn’t make much difference.

But Amy is highly intelligent, articulate and well informed. So you pay attention when she says we’re nearing the point when climate change will be irreversible.

“People accept that climate change is real,” Amy finds. “The difficulty is getting people to act on that belief.”

Amy is studying for A levels in maths, chemistry and biology at Austin Friars School in Carlisle and plans to study marine biology at university afterwards.

This year she set up conservation charity Another Way, which promoting living more ethically – for the benefit of our communities and the environment.

She believes that small, considered steps can, in the end, make a big difference.

Another Way hosts talks, workshops and practical projects – such as a scheme to plant 1,700 trees between November 23 and 30.

Her parents, Chris and Emma, and business partner Zoe Hedges, were inspired by their daughter’s example to set up a zero-waste shop with a similar name in Penrith, Another Weigh.

Now that climate change denial is on the wane, most people want to do something. But few of us would be as dedicated and determined as Amy.

Where does her determination come from? She traces its origins back 10 years.

“I was about seven when I first got interested.” Amy recalls. “I think it was dolphins to start with. Sea slugs were another fascination – they are really colourful. It gradually developed into a wider understanding.

“But every time I was on a beach I’d be looking for shells or mermaids’ purses – the egg cases of sharks – but you’d see plastic everywhere.”

It was while scuba diving that she realised how far it was spreading.

“I found wet wipes on a coral reef. It was the first time I came face to face with an eco-system being damaged. Then, when I was 12, I read a book called The Ocean of Life by Callum Roberts.”

Roberts is professor of marine conservation at York University and an adviser on David Attenborough’s Blue Planet II series.

“It talked about what’s happening to the oceans, with acidification, pollution, microplastics and over-fishing. That really frightened me. It was the first time I really became aware of the threats our oceans are facing.”

Many more of us have been made aware of those threats through our TV screens. We have seen beaches on the other side of the world littered with bottles and carrier bags, many bearing the logos of British shops.

A dead sperm whale was found to have plastic sheeting in its stomach. An albatross was shown feeding plastic to its chicks, which were certain to die as a result. A third of the fish we eat contains plastic.

Amy originally set up a campaigning organisation called Devotion to Ocean, arguing for a change in our plastic habit. “It was really good timing because a few months later Blue Planet was on TV and suddenly everyone got interested.”

Another Way broadened the campaign to other aspects of environmentalism.

“Its aim is to inspire people to try to live in a more ethical way, instead of choosing what’s most profitable or easy or convenient.”

She gets the message out primarily by giving talks. The first was at her own school but others have followed at schools and community groups - not just in Cumbria.

“I do about two a week. I feel it’s part of my education too, talking about issues and topics that are going to make a difference to our futures.”

Early on Amy had sent emails to her MP, Rory Stewart, and to local businesses – but got no satisfying responses.

“When you email a business they send back this standard-issue reply with a lot of meaningless words and no action.”

So she focuses on individuals. “If one person spreads a message to 10 people, and the next day those 10 spread it to another 10, and then those people each spread it to another 10 the day after that, and that continues, then within 10 days the whole world will have got it.”

And she is ever hopeful. She is firmly of the belief that pressure from the public can ultimately lead to change. “The plastic bag tax got introduced because enough people lobbied for it. That inspired me to found Another Way.

“People can feel overwhelmed when they hear about climate change. About 50 football pitches of rainforest are destroyed every minute. But if everyone us decided to boycott palm oil, then one of the biggest threats to our rainforests would be gone. I found that individuals can make a difference. You don’t have to wait for governments to make laws first.”

There is an assumption that destruction of the environment is of more concern to the young than the old - t is younger people who will have to live with it - but Amy notes: “Among people my age there’s a certain apathy there too.

“Many teenagers care more about their appearance, or their popularity, and are scared to stand out. I don’t find the difference between young and old that you might expect.”

Her message may or may not get through to those who need to hear it. But do nothing and it definitely won’t. “Sometimes I can feel helpless and think I’m not making a difference. But then you see how people are making changes and continuing to make changes. When someone says they’re not going to fly this year, that fills me with hope.”