The UK government slashed its flagship environmental target for planting trees after lobbying by the National Farmers’ Union – which feared, among other things, that it could reduce land values.

The decision to cut the target for woodland creation in England conflicts with Britain’s net zero strategy, which includes plans for a major increase in tree planting to absorb carbon dioxide from the atmosphere.

Documents uncovered by openDemocracy through freedom of information law reveal the NFU’s efforts to convince environment secretary Therese Coffey that the original woodland target was “extremely ambitious, if not unachievable, particularly when compared against a backdrop of current planting rates”.

It said the change in land use required to meet the target, as well as others aimed at enhancing wildlife and improving water quality in rivers, would have a “significant impact on… food production, food security but also land values”.

Upland livestock farmers could be severely impacted by the woodland target, it added, and farm profitability would be reduced.

Official figures on the amount of low quality farmland available for tree planting suggest the NFU overstated the risk to food security.

A government consultation, published in March last year, had proposed a legally binding target to increase tree canopy and woodland cover from 14.5% to 17.5% of England’s total land area by 2050. It said the target would help meet net zero emissions by 2050 and provide many other benefits, including creating new wildlife habitats and reducing flooding by slowing the flow of water off hills.

But Coffey cut the target to 16.5%, with the government’s response to its own consultation claiming that “a review of our evidence” now showed this lower figure was “the most ambitious target” that could be set.

It means reducing the government’s target for the total area to be planted by 2050 by more than 100,000 hectares, and 37 million fewer tonnes of carbon dioxide being removed from the atmosphere by trees by the end of the century, according to an impact assessment by the Department for Environment, Food and Rural Affairs (Defra).

The documents obtained by openDemocracy also show Coffey chose to ignore evidence from Natural England, the government’s nature adviser.

Natural England said about the originally proposed target: “We consider this a good level of ambition to enable effective integration of trees and woodland within the landscape.”

The Office for Environmental Protection, a public body which holds the government to account on its environmental duties, had similarly commended the original 17.5% target, saying it was “coherent with the UK net zero target” and in line with Climate Change Committee advice.

Net zero target at risk

Defra identified 3.2 million hectares of “low-risk” land suitable for conversion to woodland in England – eight times more than would be required to meet the originally proposed target of increasing the area covered by trees to 17.5%. None of the land deemed available is classed as “moderate” or “good” agricultural land.

Defra calculated that meeting the 17.5% target would have required increasing the area planted with trees each year in England from an average of 1,720 hectares in the past five years to 7,500 hectares in 2025 and 16,700 hectares by 2035. Under the reduced target, tree planting in England will instead rise to 10,300 hectares a year by 2035.

This will make it much harder to reach the target in Britain’s net zero strategy that tree planting across the whole of the UK should reach 50,000 hectares a year from 2035 to 2050.

In response to the target being cut, Defra upped its recommended ratio of conifers in the overall tree planting mix. Foreign conifers make much poorer habitats for wildlife than native broadleaf trees, but they grow more quickly and in the early years can store more carbon.

Even with the extra conifers, the 16.5% woodland target will leave 1.9 million more tonnes of CO2 in the atmosphere by 2050, and 37 million more tonnes by 2100, than the plan Coffey scrapped.

Woodland Trust chief exec Darren Moorcroft said: “Slashing tree targets by a third from what was consulted on is highly disappointing at a time when ambition and action is so desperately needed. The nature and climate crises demand transformative action and now is not the time for a loss of confidence.”

Dustin Benton, policy director at Green Alliance, an environmental think tank, said: “It makes little sense to plan for fewer trees in England from a carbon, nature or rural economy perspective.

“Well managed woodland also provides habitat that will be essential to restoring nature in the UK, and our analysis shows that paying British farmers who own the least productive land to create woodland and restore peat could increase their incomes by a fifth.”

Green Alliance’s analysis suggests a further 6% of England should be covered by trees by 2050 to deliver net zero and restore nature. That’s three times the extra 2% tree cover now planned by the government.

The think tank also calculated that if the planting were targeted at the least productive farmland, an additional 6% of tree cover could be achieved with a loss of less than 1% of the calories produced across the country, which equates to less than 0.5% of the calories consumed when accounting for food imports.

Defra said it had “carefully considered all the responses to the consultation we held last year on the Environment Act targets, and as a result have set ambitious but achievable tree planting targets which will see a five-fold increase in average planting rates”.

Richard Bramley, chair of the NFU’s environment forum, said some farmers might be reluctant to convert fields into woodland because “once land is planted with trees it’s removed from any other use”.

To persuade more farmers to plant trees, the government needed to provide “a clear and easy to access, properly funded scheme”. But he said government plans to replace EU farm subsidies with payments for “public goods”, such as tree planting, had stalled.