Liberals wanting a new way to define their sexuality and signal their green virtues can now combine the two: 2016, already seen by many as the year the world went mad, is likely also to be remembered as the year the world was gifted ‘ecosexuality’.

An attempt to catalogue all the sexualities listed on Tumblr earlier this year identified 80 different varieties including “Neu: feeling attraction towards people who are genderless”; “Iculasexual: being asexual but open to having sex” and even “Pre: a placeholder term for someone who doesn’t think they’ve experienced enough attraction to know their orientation.”

‘Ecosexual’ was not among them. Yet it’s likely to be a short-lived oversight as the movement goes from strength to strength: more than 100,000 people worldwide are now said to be identifying as ecosexual.

Amanda Morgan, a faculty member at the UNLV School of Community Health Sciences who is involved in the ecosexual movement, told Vice that ecosexuality could be measured along a spectrum not unlike the Kinsey Scale.

At one end are those who try to use sustainable sex products, or who enjoy skinny-dipping and naked hiking. At the other are “people who roll around in the dirt having an orgasm covered in potting soil,” she said. “There are people who fuck trees, or masturbate under a waterfall.”

First coined in the early 2000s when it was used mostly by people in online dating profiles, the term gained momentum from 2008 onwards when the Bay Area performance artist couple Annie Sprinkle and Elizabeth Stephens made exosexuality a personal crusade.

The couple have produced several documentaries including one depicting the “pollen-amorous” relationship between them and the Appalachian Mountain, and while touring a theatre piece across the country, Dirty Sexecology: 25 Ways to Make Love to the Earth, they officiated wedding ceremonies where they and fellow ecosexuals marry the earth, the moon, and other natural entities.

“The Earth is our lover,” their website proclaims. “We are madly, passionately, and fiercely in love, and we are grateful for this relationship each and every day. In order to create a more mutual and sustainable relationship with the Earth, we collaborate with nature. We treat the Earth with kindness, respect and affection.”

The couple have drawn up a manifesto, in which they pledge to be activists for the earth, hold being ecosexual as an identity, and exist in a community of people who “aim to buy less”. What they do buy must be “green, organic and local”.

Clause 2 is perhaps the most eyebrow-raising, however, professing: “We make love with the Earth. We are aquaphiles, teraphiles, pyrophiles and aerophiles. We shamelessly hug trees, massage the earth with our feet and talk erotically to plants. We are skinny dippers, sun worshippers, and stargazers. We caress rocks, are pleasured by waterfalls, and admire the Earth’s curves often. We make love with the Earth through our senses. We celebrate our E-spots. We are very dirty.”

Although Sprinkle and Stephens describe ecosexuality in terms of a new form of sexuality – leading a ceremony to add the letter ‘E’ to the LGBTQ2I acronym earlier this year – the pair admit that their inspiration behind the weddings was their activism on gay marriage. They wanted to harness the energy that that movement had enjoyed for environmental reasons.

Ultimately, ecosexuals believe that viewing the earth as a lover is the first step toward taking environmentalism more seriously. As Morgan puts it: “If you piss off your mother, she’s probably going to forgive you. If you treat your lover badly, she’s going to break up with you.”