A primary school teacher in the United Kingdom came under fire last week over his decision to ban Christmas cards. The teacher argued that the cards, exchanged at the school for over 170 years, have a toxic impact on the environment.

According to a report by the Daily Mail, British teacher Jonathan Mason of Belton Lane Primary School is facing international criticism over his decision to essentially ban Christmas cards in his classroom this year. Mason told students and their parents that Christmas cards are harmful to the environment.

In a letter sent to parents, Mason told parents that concerned students had encouraged him to place a restriction on the distribution of Christmas cards. Mason said in the letter that Christmas cards contribute to “ever-growing carbon emissions.”

I have been approached by a number of children recently who are concerned about the impact of sending Christmas cards on the environment. Throughout the world, we send enough Christmas cards that if we placed them alongside each other, they’d cover the world’s circumference 500 times. The manufacture of Christmas cards is contributing to our ever-growing carbon emissions. So in order to be environmentally friendly in school we will not be having a post box for Christmas cards from this year onwards. Instead, can we encourage you to save money and the environment buy not sending cards to all of the children in a class individually but instead, if you want to send a card please send one card to the whole class. Teachers can then display the cards in the classroom for everyone to see.

Students at Belton Lane Primary School, which is in Grantham, Lincolnshire, have distributed Christmas cards to their peers for over 170 years. Students and parents were quick to accuse Mason of ruining the tradition.

“I know we have to protect the environment, but these are a few Christmas cards once a year and to be told about this on a piece of paper seems contradictory,” one parent said.