A Scottish estate that became a lightning rod for disputes over wealthy “green lairds” buying up the Highlands has been unexpectedly put up for sale. The Far Ralia estate in the Cairngorms has gone on the market for £12m, three years after it was bought for £7.5m by an investment trust run by Standard Life, now Abrdn, as a way to offset carbon emissions from its properties. Its purchase led to a row with land reform campaigners, who argue this approach treats the Highlands as a commodity for wealthy absentee investors, driving up land prices while exploiting public subsidies and tax breaks for private gain. The estate, a former grouse- and deer-shooting estate covering 1,462 hectares (3,613 acres) in the Cairngorms national park, was bought by the trust as a long-term carbon offsetting, sequestration and nature recovery project. Now known as Abrdn Property Income Trust, it has so far planted 1.2m native trees including Scots pine, birch, oak, rowan and aspen, after winning £2.56m in public subsidies to help cover its costs. It has a further 200 hectares of damaged peatland to restore. In an effort to demonstrate its environmental credentials and counter criticisms of its construction work, the trust hired biodiversity specialists at the Natural History Museum to evaluate the project’s biological benefits. The museum’s team said Far Ralia’s “biodiversity intactness index” would increase from 51% at present to 94% in about 75 years – a figure land reform campaigners with Parkswatch Scotland decried as crude and badly evidenced. The estate agency Knight Frank has told potential buyers they can use it to sell carbon credits, a mechanism corporations use to continue emitting CO2. A Guardian investigation last year found most carbon offset projects were “likely junk”. Knight Frank forecasts that up to 1.5m trees can be planted, offsetting 346,000 tonnes of carbon over the next 100 years. Unusually, the estate’s next owner will have very little work to do to earn the carbon credits because nearly all the planting is completed or under way. The trust is selling all its properties and investments after a steep fall in profits from property and rising costs. Abrdn and its predecessor Standard Life had run the trust for 20 years. It was seen as one of its flagship investment vehicles. Fraser Green, Abrdn’s head of natural capital investment, said: “Stakeholders of all kinds, including investors, are increasingly conscious of the need to better manage their carbon footprint and investing in environmentally beneficial projects can play a useful role in helping them do that.” Andy Wightman, a land reform campaigner, said the sudden sale suggested Far Ralia was simply “another get-rich-quick scheme”. “National parks should be centres of excellence in nature restoration but this is best done by placing legal duties on all landowners to restore nature rather than relying on financial schemes by offshore property investors.”