A group of YouTube stars have raised more than $6m (£4.7m) to plant trees around the world by rallying their huge numbers of subscribers.

The American YouTuber Jimmy Donaldson, known as MrBeast, was challenged on Reddit in May to plant 20m trees to celebrate reaching 20 million subscribers on his YouTube channel, where he posts videos of extravagant stunts.

He then teamed up with other YouTubers to create the #TeamTrees project with a target of $20m – each $1 donation will plant one tree. Launched on 25 October, the crowdfunder raised $5m in just 48 hours, with $1.75m coming from YouTube alone, which the team claims is a new fundraising record for the site.

All donations are sent directly to the Arbor Day Foundation, a US nonprofit conservation and education organisation dedicated to planting trees. They will plant the trees around the world, starting in January, with the aim of completing the project within three years.

More than 600 creators and social media influencers have joined the initiative, many employing creative tactics to encourage donations. Jacksepticeye, the top YouTuber in Ireland with 22.9 million subscribers, hosted an eight-hour livestream in which he planted trees on the videogame Minecraft for each of his viewers’ donations, raising $153,000.

Other stunts included a gaming YouTuber donating $10 for each kill during a Fortnite tournament and a technology channel building a tree-planting cannon.

MrBeast, who has donated $100,000, admits that he has not always been the most environmentally friendly – in one of his videos, which has over 12m views, he builds a “mansion” out of cardboard boxes before setting it alight – but says now is the time to take action. In a video he said: “People keep making fun of our generation for retweet activism and not actually doing something … this is your chance to make a difference.”

Amid some suggestions that the money would be better spent preserving trees, he said: “Just to be clear we all realise 20m trees won’t fix climate change. But at the end of the day 20m more trees is better then 0! We want to take action because doing nothing is how we got here!”

YouTube has been criticised for its platforming of climate denial, as highlighted by Extinction Rebellion Youth action during the two-week October protests. A recent analysis of the site – which is the most-watched platform for 16- to 24-year-olds – found that the majority of videos about the climate crisis opposed the scientific consensus on the subject.