THE UK Government's plans to reduce carbon dioxide (CO2) greenhouse gas emissions to net zero by 2050 will result in 20 per cent of agricultural land being shifted from food production to tree planting, peatland restoration and energy crops.

The Government initiative will double the amount of woodland being planted within the next four years to 75,000 acres per annum. The number of trees planted to achieve this figure will rise to 80 million per year. From 2025 to 2035, the number of trees being planted annually will further increase to 143 million.

The Government’s 2025-2035 carbon emissions target will require an area of 125,000 acres per annum of woodland being planted, almost doubling the first four-year phase annual target. According to the Climate Change Committee, the body that advises the Government, UK woodland cover will require a landmass between 18 per cent and 20 per cent.

UK woodland cover is currently estimated at 13 per cent of landmass, almost half the woodland of France and Germany – 30 per cent and 31 per cent, respectively. The controversial UK proposals to sequester sufficient carbon out of the atmosphere by 2050 has been legally enshrined in law.

In early May, the Government announced an “urban tree challenge fund” targeting the planting of 44,000 trees close to schools and hospitals. While urban targets are realistically more achievable, mass planting in rural areas is set to be more controversial with financially under-pressure farmers facing the brunt of the proposals.

Vast areas of farmland, as well as national parks and areas of outstanding beauty will require tree planting in order to meet the targets. Sheep farmers are likely to face severe pressure to transition their businesses from meat production to forestation over the next 50 years.

Financial packages have not yet been laid out to farmers and landowners as to how this will be achieved nor, the payment lifetime, possibly until the end of the 21st century. The UK leaving the EU and the Common Agricultural Policy (CAP) provides the opportunity to move from production-based subsidies to environmental, nature and land management payments.

Another aspect not yet defined is the life-span of forestation that will result in millions of trees turning productive farmland into forests. The Government target of zero emissions runs for 30 years and the Climate Change Committee estimates a tree planting mix at one-third broadleaf and two-thirds conifer.

UK native broadleaf trees such as oak, chestnut and ash are slow-growing tree varieties compared to conifers. The Forestry Commission estimates the normal lifespan of an oak tree is 150 years (or more) and has an annual growth rate of 0.5 metres. Plantation-rate is 1,600 oaks per hectare with annual storage per hectare of middle-aged trees estimated at 118 tonnes.

The lifespan of more densely populated spruce and pine trees is 55 years, with phase one plantations reaching maturity by 2075 and second phase by 2090. These more commercially-viable trees have an annual growth-rate of 1.5 metres and can be planted at a rate of 2,500 trees per-hectare. Annual carbon storage per-hectare of mixed-age spruce is estimated at 78 tonnes.