London (CNN) Up to one quarter of UK land would be left to nature if a new plan to reduce the country's carbon emissions were introduced.

The proposal comes in a report from environmental group Rewilding Britain , which recommends restoring and protecting woodlands, peatbog, heaths and grasslands as a way to naturally absorb CO2 from the atmosphere.

It targets a total of more than 6 million hectares of land for the scheme, which its says could remove 47 million tons of CO2 from the atmosphere each year -- more than a tenth of current UK emissions.

It estimates the cost at £1.9 billion ($2.4 billion) a year, and suggests a new subsidy system could pay landowners to restore ecosystems and increase carbon sequestration.

"Our report demonstrates how land use change with nature at its heart can play a major role in our efforts to meet our targets and address climate breakdown," said Rewilding Britain chief executive Rebecca Wrigley, in a statement.