More than 1m trees have been pledged for Trump Forest, a bid by environmentalists to offset the US president’s curtailing of Obama-era clean energy initiatives by planting 10bn trees around the globe.

“US president Donald Trump doesn’t believe in the science of human-caused climate change,” reads the website for the project, launched before Trump withdrew the US from the Paris climate accord.

“So we’re planting a forest to soak up the extra greenhouse gases Trump plans to put into our atmosphere. We’re planting a global forest to offset Trump’s monumental stupidity.”

The project was launched last March and in less than a year over a million trees have been pledged from people around the world, but particularly in the US and Europe.

The donated trees are to go towards offsetting the 650m tonnes of CO2 that will be released into the atmosphere by 2025 if the president’s plans to backtrack on US climate commitments go ahead, organisers say.

The figure of 650m tonnes – equivalent to the annual carbon footprint of 33 million Americans – is calculated from Trump’s decision to roll back the US 2015 Paris agreement pledge to lower emissions by at least 26% below 2005 levels by 2025.

It would take 10bn trees – covering a landmass roughly the size of the state of Kentucky – to offset the full amount.

“We’re really pleased at how quickly it happened,” co-founder Adrien Taylor told Newshub.

“We’re just pleased to see we’re not the only people in the world who care about climate change, because sometimes it can feel like that.”

The project’s co-founder, British climate scientist Dr Dan Price, said: “In 30 years from now, when people look back on the Trump presidency as an attack on the planet and on rational thought, it would be pretty cool if the history books say his actions were negligible because the global community offset the administration’s additional emissions.

“It’s clearly a big challenge, but only recently the world record was broken when India put 66m trees in the ground in a day. If we all chip in, it is a completely realistic goal.”