A brutal east wind is cutting across this hill country – there is nothing to obstruct it.  It is a dry day, so we call it fine, but otherwise it feels like a survival exercise. It is still winter up here, no matter what the calendar says.

I am walking with my friend David Cooke in the Cambrian Mountains: the bulging massif that fills the centre of Wales. As always the wide-open spaces bring a sense of freedom but in truth it is a dismal scene: a kind of infertile emptiness surrounds us – and it stretches for miles. The interlocking ridges are clothed in tufted grass and rushes that are so bleached they look irradiated; growing on degraded soils this vegetation is neither nutritious nor diverse. I know the weather doesn’t encourage optimism but it seems to me that apart from a lot of grass, some distant conifers, and a scatter of sheep there is nothing here. These are George Monbiot’s original ‘sheepwrecks’ and, much as I baulk at his incendiary style, it is difficult not to have sympathy with his point of view right now. These hills have been nibbled down to a thin skin that barely covers the bones of the earth. The crumbling walls of a 19^thcentury mine only add to the sense of desolation. Struggling past the beaten pewter dish of Glaslyn the wind is so strong it feels personal, as though it wants to rip me from the face of the earth. At each step my walking pole flaps uselessly like a dislocated limb.

Now for the tricky bit: we have reached the edge of the great crumbling escarpment, which reveals an enormous but hazy view to the west. To get to our destination, which is 1000 feet below us, we need to descend on a path that is both steep and loose. My knees would find that a bit of a challenge at any time but today the wind pursues us over the edge, hurtling into our backs and threatening to blow us over. It is impossible to walk upright and I proceed in a half crouching stagger, sliding across the loose shale; only my stick prevents me from falling flat on my face. I’m grateful there is nobody around to capture this for YouTube. As I struggle forward my phone keeps bleeping for attention, so when we stop for a break I check the messages. This highlights a very modern incongruity: in this wild and desolate place, where we see only one other person all day, I am receiving live feeds from friends on a raucous and crowded Extinction Rebellion protest in central London. I send a photograph of ‘here’ and receive a reply “it’s all connected” – and she is so right. I have written before how much I value the culture of the farming community which has shaped these hills for centuries but today it is hard not to agree with those who refer to this as an ‘ecological desert’. We have made it thus.

The path is easier now and David and I are glad to have got this far without mishap. And what a difference 1000 feet make. Down here the trees are coming into leaf, blackthorn foaming with blossom and primroses are posing along the path side. Most interesting of all is a half-mile long woodland on the downside of the path, which has been planted in the last ten years. Conservationists can be a bit sniffy about tree planting mainly because native trees, which will grow up spontaneously if you fence out the sheep, are very well adapted to local conditions; unlike many planted trees which often start life in a Dutch nursery. But that seems a bit picky in this instance. These trees are appropriate species (birch, rowan, hazel and oak), well spaced and not planted in regimented rows. With bracken and bramble developing underneath this nascent wood is so three-dimensional compared to the blasted heath above, which did little more than prevent sky meeting rock. It will take hundreds of years for this to become a fully functioning woodland but in the meantime it will soak up carbon dioxide from our polluted air, inhibit flooding, recondition the soil, provide increasingly good wildlife habitat and be a delight on the eye. It must have been grazing land until recently; perhaps a farmer has given it up as part of an agri-environment scheme. Would that be a better future for the more degraded areas of our hill country, where sheep farming is only kept alive with government subsidies? I find that a hard question to ask but it is becoming even harder to dodge.

Looking at this elegant young wood and hearing Extinction Rebellion’s desperate alarm calls points up this existential dilemma for the hills. How much longer can I go on saying ‘on the one had and yet on the other’?  Time is very short now.