High in the Conwy valley, amid the rugged splendour of Snowdonia, children from a local school are measuring the depth of the peat being restored by far-sighted farmers addressing a new reality: renewing the hills and uplands to help nature's recovery.

For the young pupils from the Ysgol Ysbyty Ifan, the exercise represents science with an edge in the wild beauty of the great Welsh outdoors, beside one of the largest blanket bogs in the principality – the Migneint – where the 11 farmers have grazing rights.

In a riveting film, a nine-year-old well versed in the climate emergency describes how this bog, “vast and remote”, stores carbon on a huge scale. “But degraded peatlands damage our environment by releasing greenhouse gases like carbon dioxide into the air,” she explains authoritatively in Welsh. “This contributes to global warming.”

In this small corner of a splendid National Park, the children are raising an issue at the heart of our challenge to reverse a post-war draining programme meant to ‘improve’ our moorlands – but which, in reality, only succeeded in degrading them.

To achieve the turnaround on the Migneint, thousands of ditches – opened up to speed drainage decades ago – are being blocked as part of an extensive renewal programme. As the nine-year-old explains, in the helpfully sub-titled film, this is important to “re-wet and restore the Migneint to its natural, wet state … to tackle the climate emergency we are all facing”.

Restoring peatlands represents one of our greatest climate challenges, while also presenting cash-generating opportunities for those living near them. Covering an estimated 11,500 square miles, they are prime candidates for being returned to a near-natural state – call it ‘wilding’ if you must – with one overriding objective: locking carbon in the ground rather than letting it leach into the atmosphere. That's an urgent task because, while only 22% of peatlands are in a relatively good condition, they still account for a quarter of the UK's drinking water, filtered through the peat into streams, rivers, reservoirs – and valued at almost £888 million in 2016. And, just think: they could be delivering more.