Theories that the earth’s climate is changing as a result of human activity have been acknowledged as an elaborate joke perpetuated by almost all of the world’s climate scientists.

“It was good while it lasted,” said Rajendra Pachauri, chair of the Intergovernmental Panel on Climate Change (IPCC), “but it’s time we came clean. Global warming was an April Fool’s Day gag that got out of hand. We really didn’t expect it to go on as long as it did.”

The intricately crafted fabric of lies began to unwind towards the end of 2009, when hacked emails from the University of East Anglia (UEA) revealed attempts to manipulate data to fit a predetermined pattern. The emails called into question the validity of the so-called ‘hockey stick’ graph, which suggests a rapid increase in the rate of global warming during the 20th century.

Further revelations in 2010 have revealed as baseless the IPCC’s assertion that the Himalayan glaciers will melt by 2035.

“In retrospect, we perhaps should have picked a more gently curved sporting implement, like a jai-alai cesta, but we thought ‘hockey stick’ was catchier,” said Pachauri. “We can’t really blame the UEA guys for messing up. We just ended up facing so much scepticism that we were asking the scientific community to keep the joke going with more and more ridiculous ruses.

“We were always going to come a cropper one day. We were just unlucky to have come up against the scrutiny of some top-class scientific luminaries at world-renowned institutions, such as Glenn Beck of Fox News.”

The admission will also set minds at ease about repeats of catastrophic weather events like Hurricane Katrina, which Pachauri conceded was actually generated using a cunningly concealed wave machine located in the Gulf of Mexico. Scientists, meanwhile, no longer distracted by their climate japery, are expected to return to their core business of developing biological weapons.