A report by the British government's official climate change advisory committee has recommended people reduce their intake of beef, lamb and dairy produce by one-fifth, with the possibility of taxes on meat and dairy products to encourage people to change their habits.

The recommendation is the stand-out observation from the Committee on Climate Change, or CCC's, suggestions as to what can be done meet the government's climate change targets, which also include ideas for how to revise farming activities.

"We can't meet the government's 2050 Net Zero target without major changes in the way we use the land, the way we farm, and what we eat," CCC's Chief Executive Chris Stark told the BBC.

"But it's very important that we don't then replace that with the importation of higher greenhouse-gas-intensity meat from abroad. We will need a strong trade policy to make that happen."

Committee Chairman Lord Debden backed his comments, saying it was time for deeds not words.

"Changing the way we use our land is critical to delivering the UK's net zero target," he said.

"Doing so can provide new revenue opportunities for farmers, better air quality and improved biodiversity. But major changes are required and action from government is needed quickly."

The report comes at a time when many Britons change their dietary habits to make up for Christmas over-indulgence. This year, the concept of Dry January, when people refrain from drinking alcohol, has been joined by Veganuary, with widespread campaigns to get people to eat differently.

The report's authors call for the promotion of plant-based alternatives to meat products, and say reducing meat and dairy consumption would cut the amount of carbon dioxide produced by farms, and also free up land currently used by livestock.

It is estimated that over the last two decades, there has been a 20 percent drop in the number of sheep and cattle in the United Kingdom, with numbers expected to fall further in the years to come.

The National Farmers' Union, also known as the NFU, welcomed some of the suggestions, but warned that there were areas of thin soil where livestock was the only effective way of utilizing the land.

"Of British land, 65 percent is only suitable for grazing livestock and we have the right climate to produce high quality red meat and dairy," said NFU President Minette Batters.

"Therefore it makes sense that, when talking about environmental impact, the public continues to support British livestock production. Plant-based products do not always necessarily have a lower impact on the environment."

Organic agriculture campaign group the Soil Association called for "less but better meat, sourced from organic and agroecological farms, and an end to intensively farmed meat".

Vicki Hird of food quality campaign organization Sustain said she was worried people might just eat more pork and chicken instead, without consideration for animal welfare. "We need to see more focus on genuinely agroecological and mixed farming, diversifying production, nature restoration and sustainable diets," she said.