Farmers have criticised Cambridge University's decision to drop beef and lamb from its catering outlets in a drive to reduce emissions.
The university said that removing red meat from its menus has cut food-related carbon emissions by a third.
Plant-based substitutes have replaced the meat in its 14 outlets since October 2016.
Prof Balmford, of Conservation Science at the university, triggered the changes.
He said: "It is hard to imagine any other interventions that could yield such dramatic benefits in so short span of time."
But the NFU said the ban is 'too simplistic'. Instead, the union highlighted the sustainability of British-produced beef and lamb.
NFU Vice President Stuart Roberts said: “Reducing greenhouse gas emissions is a challenge for each and every one of us, but banning all beef and lamb, regardless of where and how it is produced, is too simplistic an approach.
“British beef and lamb is among the most efficient and sustainable in the world due to our extensive, grass-based systems, meaning our greenhouse gas footprint is 2.5 times smaller than the global average.”
He said British farmers are aspiring to produce the most climate-friendly food in the world as the industry looks to become net-zero by 2040.
Mr Roberts added: “It is good that schools and universities are looking at how they can play their part in the climate change challenge, but it is not a case of simply removing meat from the menu.
“Instead, they should be considering their sourcing; where their produce has come from and the sustainability of production.”
Farmers on social media also criticised the university's move. Welsh farmer Gareth Wyn Jones, who has appeared on numerous television programmes, said Cambridge should 'get its house in order and back local grass-fed livestock'
Perthshire farmer Finlay McIntyre said it is a 'sad situation' when the 'great bastions of learning' are 'ignorant'.
"Beautiful mountain bred and heather-fed cattle, sustaining fragile ecosystems and fragile economies. What’s not to like?" he said on Twitter.
Over 3000 students from outside UK all traveled to @Cambridge_Uni— Llyr Derwydd ?????????????? (@LlyrDerwydd) September 10, 2019
How environmentally friendly is that????
I know my beef burbs but not as much as 3000 students flying.
5.3t of carbon for 1 single flight London to Heathrow to Beijing
Come on Cambridge!! pic.twitter.com/Htyc27Mhkq
Goldsmiths, University of London has also announced it will stop selling products containing beef at campus food outlets as part of a wider move to become carbon neutral by 2025.
Farm groups widely criticised the ban as 'misunderstanding' the differences between British beef and beef produced elsewhere.