On a remote patch of land in the south-west of Ireland lies a precious fragment of a lost world – owned and managed by one man. Eleven years ago, Eoghan Daltun sold his house in Dublin and moved to his new home, an old farm on County Cork's rugged coast. The farm, on the Beara Peninsula, included a strip of native woodland, something that is now incredibly rare in Ireland, as well as Europe. Daltun saw that 32-acre (13-hectare) patch of ancient trees as his very own temperate rainforest – a type of mossy forest once far more common in Britain and Ireland, made possible in part thanks to moist island air.
By pulling out heaps of non-native plants, including rhododendron, and erecting a fence to keep sheep and deer from grazing the area, Daltun gave his forest a chance to flourish and expand. Life has, in fact, exploded.
In late spring, the forest becomes a sea of flowers. "It's just, it's really beautiful," Daltun says. He calls it an "ecological resurgence", explaining that there's been a noticeable increase in the presence of birds and insects, too.
The picture elsewhere is less than leafy. The Republic of Ireland has the lowest forest cover of any country in Europe. It wasn't always that way. Once, 80% of the land here was covered by native trees – the figure now just 1%. Farmland dominates, covering 72% of land in the Republic and 75% of land in Northern Ireland. For an island so often referred to as "green", there's a striking lack of wilderness.
Ireland's dearth of biodiversity has long been noted, and it is getting worse. A 2019 report found that 85% of Ireland's habitats had "unfavourable" conservation status, and nearly half of habitats were in decline.
It's difficult to put into words the sheer joy and pleasure of seeing a wild native ecosystem return on its own steam – Eoghan Daltun
One option to redress this loss is "rewilding" – the process of returning human-altered land to a more natural, ecologically-rich state. Rewilding could even act to counter climate change, through establishing ecosystems that lock in carbon and reduce greenhouse gas emissions.
Across Ireland, rewilding projects, including Daltun's, are now springing up. But these schemes are sometimes controversial and can prompt heated debates – for example, when environmentalists suggest the reintroduction of large predators, like wolves. Many wonder to what extent Ireland's biodiversity can really be rescued through rewilding. Is it even possible to bring back a long-lost wilderness in the 21st Century?
The artist Julian Friers imagines what large animals would have looked like roaming Ireland's prehistoric landscape (Credit: Julian Friers)
Daltun's Atlantic rainforest is full of native tree species including oak, birch, willow and hazel. He says by simply clearing out competitive, non-native species and protecting the forest in order to allow it to grow, nature has done a lot of the rewilding work for him. He says he would like the place to serve as an example for other such projects around Ireland.
"It's difficult to put into words the sheer joy and pleasure of seeing a wild native ecosystem return on its own steam," he says.
The term "rewilding", because of the "re" part, conjures up the romantic thought of returning ecosystems to a prior, ideal condition that has since been denuded. While we know that there was significantly more forest cover in Ireland just a few centuries ago, the specifics of ancient ecosystems are often unclear. For instance, there's no evidence of beavers in Ireland but many ecologists argue that wild Irish habitats would suit them. But to what extent? Plus, if rewilding is the goal – what is the target era? The resurrection of wildlife as it was 200 years ago, or 2,000?
If I were to focus my efforts on one thing, I would talk about wolves – Pádraic Fogarty
For many, the conversation starts with the lost native animals that could in theory be reintroduced. Julian Friers is an artist living in the north of Ireland who has pictured what lost ecosystems looked like – literally. His paintings of extinct Irish animals show long-departed creatures in familiar places. Some are gone forever, such as the woolly mammoths who once plodded around what is now County Antrim in Northern Ireland.
"Whenever I started looking into how many things had become extinct, it just got more and more interesting and took me further and further back, timewise," explains Friers.
Some of his paintings, however, depict potential candidates for reintroduction – including the lynx, which still exists in some parts of Europe, such as Spain. Those paintings act unintentionally as prompts: "Look at this unexpected Irish creature! That's what a successful reintroduction programme could look like." Friers said it would be "fantastic" if his work were used to inspire reintroduction projects.
"It would be just great [to have] things like the lynx back," he says.
Only rare scraps of Ireland's previously widespread temperate rainforest remain (Credit: Eoghan Daltun)
But returning large carnivores to the wild in Ireland is a divisive idea. The Green Party in the Republic of Ireland has called for wolves to be reintroduced after 250 years of absence, though there are no official plans to do so yet. It's possible that wolf reintroduction could help in the fight against climate change. Perhaps through controlling non-native deer populations, the grazing of forested and mountainous areas would reduce. That in turn might increase levels of vegetation and the amount of stored carbon, for example.
But no-one really knows whether this benefit would arise and some say bringing wolves back could be dangerous for people and livestock. Ireland, after all, does not have a vast expanse of wilderness akin to the Yellowstone National Park in the US, where conservationists successfully reintroduced wolves in 1995.
And yet for some environmentalists in Ireland, there's no better topic of discussion.
"If I were to focus my efforts on one thing, I would talk about wolves," says Pádraic Fogarty, author and campaign officer for the Irish Wildlife Trust. He argues it's important not to shy away from tricky conversations – and he thinks the very notion of wolf reintroduction gets people thinking about restoring biodiversity, generally.
But there are other, less emotive species, that Fogarty thinks could be reintroduced. These include the corn bunting, a small light brown and rather plump-looking bird, and sturgeon, a large river-dwelling fish that has been extinct in Ireland since 1967.
However, as Neil Reid at Queen's University Belfast points out, it's not always clear what groundwork is needed to ensure reintroduction programmes will go to plan. In 2001, golden eagles were brought back to Ireland in County Donegal's Glenveagh National Park. Although the birds have sustained a population there ever since, their numbers have not grown as expected.
"It was predicted that by now we should have 50 to 60 pairs," says Reid. "We are well short of that." There are, in fact, just 25 known pairs. Reid says surveys by his student have found that there is not enough prey for the eagles in the area, such as hares and red grouse. That might be because the park is being over-grazed by deer and sheep, suggests Reid.
This is why habitat management is so important for any rewilding effort. Fogarty has visited Daltun's reinvigorated forest in County Cork and describes it as "amazing". He says that, on the road to species reintroductions, conservationists could start by following this example of preparing suitable habitats, encouraging fragmented patches of native forest, peatland and wetland around Ireland to expand.
The vast majority of the trees that do exist in Ireland today, explains Fogarty, are actually in non-native commercial plots, such as dense pine tree plantations. "Which is mostly very low biodiversity," he says, adding that he would like to see 30% to 40% of the island carpeted in native forest or wetland.
Peat has historically played an important role in Ireland's energy, but this carbon-intensive fuel is now being phased out (Credit: Getty Images)
There are schemes afoot in this vein. Take the 11,000 hectare (42 sq mile) wilderness area in the Nephin Beg mountains of County Mayo. Here, 4,000 hectares (15 sq miles) of non-native pine are to be transformed into a patchwork of native trees and wetland. And there are tree-planting efforts, too. The devolved government in Northern Ireland currently plans to plant 18 million new trees by 2030. Half will be native species and, among those, one million are to be planted by Northern Ireland Water.
Then, of course, there are the bogs. Ireland is famous for its once plentiful peatlands – notable because this type of wetland can store more carbon than similar-sized patches of forest when left intact. More, even, than tropical rainforest such as the Amazon. But Ireland's pristine raised bogs have dwindled to just 1% of the area they used to cover.
Huge volumes of peat were extracted and burned as a means of generating heat or electricity. The use of peat as an energy resource will end in the Republic of Ireland by 2028 but large tracts of exploited peatland have been left barren, says Catherine O'Connell, who was chief executive of the Irish Peatland Conservation Council until December. In winter, these areas become muddy and treacherous, with little or no plant life. And in the summer, they dry out into great seas of dust.
"It's a desert – it's a brown desert," says O'Connell.
There are efforts to re-wet some peatlands and encourage the sphagnum moss that grows on them to flourish again. This would benefit a variety of insects and birds. But in 21st-Century Ireland, simply giving land back to nature is sometimes unpopular. People, understandably, don't want commercial opportunities to go to waste. O'Connell thinks compromises are possible.
"Develop windfarms and wetlands together on these sites," she says. "You can have your windmills but they're going to be in a wetland."
There are examples of windfarms that have been designed in exactly this way – such as the 80 megawatt Mount Lucas Wind Farm in County Offaly. O'Connell describes this as "probably the best attempt" to allow exploited peatland to return to a more natural state, while retaining some commercial function.
Reinvigorated wetlands and peatlands could attract tourists, local school groups, or people looking for somewhere full of wildlife in which to exercise – if managed properly, such attractions could be part of how rewilding projects sell themselves to the public, adds O'Connell. (Read more on County Offaly's plans to put drained bogs to new uses)
When peatlands are left to regenerate, they can become a haven for biodiversity (Credit: Getty Images)
But peatlands are, in land-area terms, a relatively small part of the puzzle. With such vast areas devoted to farming in Ireland, reintroducing wilderness to farms is one of the greatest challenges ahead.
Reid says getting to grips with this issue is crucial. He points to the fact that significant proportion of Irish farms are not economically viable. Research from the Republic of Ireland's agricultural research agency Teagasc suggests that a third of farms are in this situation. Because government subsidies are already used to keep some farms afloat, Reid and others wonder why the money could not instead be used to pay for rewilding projects on economically defunct farms. Food production could be intensified, if necessary, on more successful farms.
"The only equation that works is to release that land that is suboptimal, to allow nature back into those parts," says Reid.
But rewilding schemes that affect farmland are not welcomed by some farmers, as they may hinder their ability to work. There's also little clarity on how sustainable such projects might be – would they always guarantee future income for former farmers whose land is now subject to rewilding efforts?
Jane Stout at Trinity College Dublin thinks the way forward might be to allow farmers to take control of the solutions themselves. She points to The Burren Programme, a scheme in the west of Ireland that has channelled public funding to farmers who themselves nominate and manage conservation projects on their own land, such as wildlife habitat restoration.
Government subsidies could encourage this sort of practice on farms all over the country, suggests Stout. Most farms have hedgerows, lands, ditches or even patches of wetland and forest. At the moment, however, farmers have little incentive to conserve them.
"These things that are part of the traditional farmed landscape are really high-quality elements for biodiversity," says Stout. "I think it's really important that in the next round of farm subsidies and payments, there is proper recognition for the value of these non-farmed habitats."
Andrew Bergin is a farmer in County Kildare. He produces cereals, legumes such as peas and other crops. He also belongs to a group of farmers aiming to reduce their dependency on pesticides while taking better care of wildlife habitats, such as hedgerows.
Nature-friendly farming can help protect the wildlife that remains in Ireland (Credit: Alamy)
For the past six years or so, Bergin has experimented with a 10-hectare (25-acre) plot on his farm. His experiment involves using fewer chemicals and monitoring the microbiology of the soil.
"We're trying to stimulate the biology in the ground," he says. "We haven't used an insecticide in, I think, at least five years."
He's almost stopped cutting back hedgerows, too – except for when growth presents an obstruction to vehicles on farm tracks, for example.
It's still early to say whether switching to more nature-friendly farming is sustainable and effective but Bergin has been encouraged by a noticeable boom in birdlife on his farm. "You have larks by the dozen here," he says, full of enthusiasm.
The more you look at it, the more rewilding, in practice, looks less like a throwback to the past and more like a vision of a very different future. Ireland is an island that has been drastically changed by humanity but it is nonetheless a place packed with wild potential. Unlocking that potential could drastically improve biodiversity on the island and that, in turn, could help Northern Ireland and the Republic of Ireland meet their various climate targets. Targets that are, incidentally, still a long way from being met.
A few pioneers are showing the way. As Eoghan Daltun says, "I do think that we need to start looking to strike a different kind of balance.
"We need nature, you know, on all sorts of different levels."
The emissions from travel it took to report this story were 0kg CO2. The digital emissions from this story are an estimated 1.2g to 3.6g CO2 per page view. Find out more about how we calculated this figure here.
If you liked this story, sign up for the weekly bbc.com features newsletter, called "The Essential List". A handpicked selection of stories from BBC Future, Culture, Worklife, and Travel, delivered to your inbox every Friday.