President Donald Trump took part in a tree-planting ceremony today at the White House to mark Earth Day, but was mocked for the effort amid his continued refusal to tackle the climate crisis.

Accompanied by the vice president Mike Pence and his wife Karen, the president and the first lady, Melania Trump, marked Earth Day and Arbor Day at noon on the South Lawn. Earth Day is in its 50th year, with millions estimated to take part in the annual day of environmental action to tackle the monumental environmental challenges facing our planet.

Before planting a tree day, the president said: “We’re planting 10 beautiful specimen trees. They’re specimens. All specimens. People may think that’s an exaggeration or that’s a Trump term. Actually, they’re sold as specimens. They cost more money but they are better. I buy a lot of ‘em,” CNN reported.

David Doniger, the senior strategic director of Natural Resources Defense Council’s Climate and Clean Energy programme, tweeted: “Only 999,999,999,999 to go for Trump’s Trillion Tree program announced at Davos (anyone remember that?)”

Emily Samsel, press secretary for the League of Conservation Voters, tweeted: “During the pandemic, @realDonaldTrump​ has rolled back clean car standards, undermined mercury protections, & refused to strengthen air quality rules -- all of which pollute the air & put folks at higher risk of COVID-19 complications. For #EarthDay​ Trump planted a f*****g tree.”

Aaron Rupar, of Vox, wrote on Twitter: “Trump spouts total nonsense about ‘specimen trees’ and how many of them he buys while Melania looks on.”

Trump has long denied the scientific consensus on the threat of climate change, saying at a 2015 rally: “Obama’s talking about all of this with the global warming and … a lot of it’s a hoax. It’s a hoax. I mean, it’s a money-making industry, okay? It’s a hoax, a lot of it.”​

A defining feature of the Trump administration has been its rollbacks of environmental regulations and policies, including cancelling a requirement for oil and gas companies to report methane emissions; amending rules on how refineries monitor pollution in nearby communities and gutting ambitious Obama-era vehicle mileage standards that were intended to tackle fossil-fuel emissions and reduce air pollution.

Trump has also called time on the US’s participation in the Paris climate agreement and continues to champion his allies in the oil and gas industry.

Earth Day events were upended by the coronavirus crisis, but the movement is taking 72 hours of digital action instead, focusing on the theme of climate action. It comes after the pandemic forced the UN to postpone the COP26 international climate conference set to put countries back on track to avoid climate breakdown.

Meanwhile, the lockdowns introduced across the world have seen the skies clearing of pollution and wildlife returning to deserted streets, while US oil prices plunged below zero for the first time in history.

Last night, Trump tweeted his support for the fossil-fuel sector: “We will never let the great U.S. Oil & Gas Industry down. I have instructed the Secretary of Energy and Secretary of the Treasury to formulate a plan which will make funds available so that these very important companies and jobs will be secured long into the future!”