Sir, – re 'Forestry carbon fail', your front page article of May 27 edition. This illustrated perfectly what is wrong with the carbon code and the way additionality is calculated.

As Pat Snowdon said, the additionality test would fail if planting a woodland is more profitable than previous land use. But the calculation included planting grants, ie government subsidies. This is an appalling misuse of government money.

The plantation should be able to claim carbon units, but only qualify for planting grants if the project does not exceed the profitability of previous land use, ie the reverse of the current situation.

This would reduce the cost to government, replace the certainty of planting grants with the risks of the carbon market, but also increase the likely rate of return and because of the lack of certainty of return, probably reduce the escalating price of forestry land.

It also might avoid the necessity for Andrew Thin (in another article in the same issue) to go back and study early-learner economics. He clearly doesn’t understand that, if the money supply is exponentially expanded by 'quantitative easing' into an economy which is flat on its back due to Covid, the money has to go somewhere.

So it goes into asset prices, including land, which is precisely what happened between 2012 and 2020. Granted, the recent price rise in forestry land was exacerbated by the government’s policy on carbon credits but that was not, as he suggested, the main cause of the general escalation in the price of land.

Farmland prices in fact rose exponentially during the period of lax monetary policy only beginning to fall after our decision to leave the EU. That fall continued unabated except for 2020-2021 when the attraction of forestry became apparent and the incentives for City institutions to fulfil their sustainability targets began to bite.

Mark Tennant, Chairman of Scottish Land and Estates