A trend on the photo-sharing app Instagram that promises to plant a tree for every photo of a pet shared has "spread out of control" according to its organisers after it was shared millions of times.
The post - which has now been shared by more than four million people - reads: "we'll plant 1 tree for every pet picture".
But questions were raised over where the post came from, and whether whoever started the trend will be able to honour the commitment of planting four million trees.
The photo sharing app Instagram - which is owned by Meta - allows users to start trends, which can involve using certain labels, soundbites, and stickers.
The trend can then be shared by users across the platform.
The tree-planting trend in question came in sticker form. It asked users to post a picture with their pet, and promised to plant one tree for every picture.
The trend was started by a group called PlantATreeCo - an environmental organisation that was set up with the aim of planting a million trees by the end of 2021.
PlantATreeCo aims to raise awareness of environmental issues by starting social media campaigns.
The group started the "pet picture" campaign with honest intentions, but said they didn't realise quite how popular the trend would be.
In a statement on Instagram, PlantATreeCo thanked users for sharing their pet pictures, but said they immediately realised the post would "grow too big" and that they didn't have the resources to plant that many trees.
It then deleted the pet picture post, but all this did was remove the PlantATreeCo credit from the trend. This means that the post can still be shared by users.
Although the group can't plant four million trees immediately, it says it will use the publicity generated from the post to find financial backing to follow through on its promises.
"Even though we deleted [the post], the stories continued to spread out of our control", PlantATreeCo wrote on Instagram.
"We want to use this awareness for lasting impact, so we created this fundraiser.
"Please share this post and the fundraiser on your story, and tag all your friends, celebrities, and Instagram so they can see this and so we can ACTUALLY plant 4 million trees".
Instagram distanced itself from the post, but said the fact that four million people shared it shows how effective the app can be.
“The ‘we’ll plant one tree for every pet picture’ trend shows the power of the Instagram community to raise awareness on important topics”, Instagram said.
The company said the trend was started by an independent Instagram account, and not Instagram itself.