You referenced Climate Change Advisory Council chairperson Marie Donnelly rightly highlighting the absence of guidance to Irish suckler farmers on a “low emissions farming future” in your editorial last week.

We have little or no Irish peer-reviewed research on how to graze poorer-quality land producing meat, whilst doing what are the now golden four goals that will be paid on in the new CAP.

They are maximising biodiversity, carbon sequestration and water quality, while minimising methane production.

What we do know, from British research, is abandoning that land to be “left idle”, as you suggest, is inevitable and will not achieve those four goals.

It won’t lead to a reversion to a “natural vegetation”, but only leads to a monoculture of purple moor grass on hills, as deer prevent the natural succession of shrubs or trees.

Drive along such a monoculture of 20 miles of deer-grazed abandoned lands from Lough Barra to Gartan Lake as an example.

Or worse, drive to other abandoned lands in Donegal from Pettigo to Laghey or from Dunlewey to Crolly and see how a monoculture of Rhododendron has wiped out all other vegetation.

Such unchecked land abandonment has a societal impact, an exodus of farm families to the towns will devastate the west.

With global warming bringing droughts and high temperatures in temperate countries, it is vital to plan for a resurgence and retain farming skills that will be needed to meet future demand to feed a 10 billion population by 2050.

Such skills for example are gone, never to return, on the abandoned farms of Gaoth Dobhair and the Rosses in Donegal.

A vacuum of knowledge allows management practices by State bodies, based on no research, to go unchallenged as somehow optimal, and farm families are outbid by Coillte or the National Parks and Wildlife Service (NPWS) for upland farms to abandon to deer.

The NPWS grazes 16,000ha and An Taisce 2,000ha respectively in Donegal, solely with red deer. Coillte has over 40,000ha of land unplanted and unplantable in Ireland, again mainly grazed by deer.

Where are the publications showing this is best practice for biodiversity? On what published Irish research can we guide the Irish hill farmer on the optimum stocking rates, grazing season and mix of livestock species which will both achieve food production and draw down supports to achieve these new golden objectives in a future CAP?

Scottish research at Scotland’s Rural College (SRUC) emphasises land abandonment is detrimental to biodiversity and suggests the ideal is a mixture of cattle and sheep, not deer, or indeed the water buffalo provided for on wetlands in the Nature Restoration Act.