The UK needs to take urgent action to reduce greenhouse gas emissions from land use by two thirds to deliver on its economy-wide pledge for carbon neutrality by 2050, government advisers have warned.

In a report published on Thursday, the Committee on Climate Change (CCC), the UK government’s official climate adviser, has called for rapid and major shifts to farming practices, agro-forestry and consumer behaviour to decarbonise the UK’s land sector.

Emissions from land use have risen since the 1990s to represent 12% of the UK’s total greenhouse gas emissions in 2017. The CCC outlined what it would take for the UK to reduce emissions from land use by 64% by 2050.

The CCC has previously warned that achieving carbon neutrality in the UK would need to involve all sectors of the economy but that not every sector would individually need to achieve net zero emissions. Instead, negative emissions technologies, such as carbon capture and storage, could be used to offset remaining emissions.

Under the CCC’s latest recommendations, a fifth of all agricultural land needs to be used to suck carbon from the atmosphere, by planting trees, restoring peatlands and soils and growing bioenergy crops with carbon capture and storage (BECCS). Growing timber and bioenergy crops would also generate further emissions cuts in other sectors of the economy when used with carbon capture and storage.

The advisers said this would enable the use of land to reduce carbon emissions while also balancing other priorities for land use, such as food production and flood protection.

Among recommendations, the report urged a cut in consumption of carbon-intensive food such as beef, lamb and dairy by at least 20% per person and a reduction in food waste by 20% by 2050. Such changes would help reduce methane emissions from livestock and release land for tree planting and growing bioenergy crops, the report said.

This dietary change would imply reducing cattle and sheep numbers by 10% compared with 2017 levels by mid-century – less than the 20% decline experienced in the UK in the past 20 years.

The report comes days before the UK’s first climate citizen assembly is due to gather on Saturday to thrash out solutions to achieve the net zero emissions goal by 2050. The UK is also in the midst of reviewing its agricultural policies as its prepares to pull out of the EU’s Common Agricultural Policy (CAP) as part of Brexit.

Last year, the UK was the first major economy in the world to set a carbon neutrality goal in law. Much of the country’s credibility as host to this year’s critical UN climate talks in Glasgow in November lies on the ability of Prime Minister Boris Johnson’s Conservative government to come up with a concrete plan to achieve its 2050 target.

CCC chairman Lord Deben said the report was one of “the most important” pieces of work produced by the committee. “Changes to land use are absolutely essential” for the UK to meet its climate goal, he said, citing the critical role of farmers and land-managers in delivering the changes.

“These are major changes and cannot be delivered in the normal course of business,” he warned.