We’re almost at the point of no return,” said one of the representatives at the Galactic Federation meeting.

Commander Eaton, the only human in the room inside Area 51 — an Air Force military installation in the Nevada desert — thought of this speaker as ‘the Reptile’. Naturally, the three alien representatives in the federation had complicated official names. But to Commander Eaton, they had always been the Reptile, the Green and the Humanoid.

He couldn’t help the repulsion he experienced whenever he looked at the Reptile, who had a human form but reptilian characteristics. He was grateful, as always, that it was the Green who was telepathic, and not the Reptile, who would certainly have been offended by his internal reaction to him.

“I believe Commander Eaton and his colleagues have formulated a pertinent strategy,” said the Green, now demonstrating that capacity for telepathy. Commander Eaton thought of this alien as ‘the Green’ because he, or rather it ­— since it was genderlessresembled the stereotypical representation of extraterrestrials, with a long, thin green body, an oval face and large dark eyes.

The three alien species had been visiting Earth for thousands of years and had bases all over the planet, situated deep under the ocean, where humanity had yet to explore. Their principal objective was to study and observe the human species; the Greens in particular were known to experiment on people, something Commander Eaton found extremely distasteful.

Today, they were meeting to discuss the Point of No Return, the inevitable destruction of the planet because of global warming — inevitable, unless humanity took immediate action to reverse it.

“We have made a decision,” said Commander Eaton, speaking for the human division of the federation. “We are going to reveal your existence to humanity.” He waited a moment for that revelation to sink in, then continued. “We will tell our fellow humans what you have told us, of the destruction of other planets because of conditions similar to those caused by global warming, how we must take drastic action now, before it’s too late.”

When he stopped talking, there was silence, and then the Reptile said, “Humans have been hearing that message for decades — ‘Take drastic action now, before it’s too late.’ It won’t change anything.”

Commander Eaton looked at the Reptile with a mixture of repulsion and irritation. “We are going to reveal the existence of alien species on Earth,” he said. “This will be the biggest revelation since… well, since Darwinism or the existence of the universe. It will put things in perspective. It will wake people up.”

“If they even believe it,” said the Reptile.

“That’s where you come in,” said Commander Eaton, ignoring the Reptile’s scepticism and turning to the Humanoid — so-called by the commander because it most closely resembled a human, though with vivid green eyes and almost translucent skin.

A few weeks later, the Galactic Federation published a video, sanctioned by governments around the world, of the commander and the Humanoid addressing humanity — using not the word ‘aliens’ but “friends from other planets” — and describing the self-imposed destruction of other species in the universe and the actions individuals, corporations and governments must take now to save the planet.

The response was immediate and dramatic, as Commander Eaton had expected. But it was also more sensationalised and controversial than he had hoped. In the end, instead of uniting humans through a common cause, it divided them.

There were those who believed the message was authentic, who were grateful for the warning of the visitors and dedicated to taking action to reverse global warming. But there were also many who didn’t believe aliens existed and accused the world’s governments of staging an elaborate hoax to realise some liberal agenda.

“If some green-eyed freak tries to stop my corporation drilling for oil, I’ll be waiting with my A51 assault rifle,” one high-profile CEO said in an interview that went viral.

And some political parties were using anti-alien sentiment to attract voters, with slogans like “No aliens wanted,” “The global warming lie” and “Our planet, our way.”

“In the end, humans believe what they want to believe,” said the Reptile at the next Galactic Federation meeting, a year later.

Commander Eaton didn’t have to be telepathic to sense the despair in the room, and was irritated that the Reptile had understood human nature better than he had.

“I’m sorry, my friend,” said the Humanoid. “But we are all leaving you. It’s too dangerous for us to remain here as the planet self-destructs.”

“I understand,” said Commander Eaton, who had been expecting the aliens’ departure. “But we’re coming with you, right? Or at least some of us?” The best of us, he thought but didn’t say, ashamed of the thought, which he knew the Green would sense. “There must be some planet somewhere that we can inhabit.”

“Oh, there are many,” said the Reptile, “but we’ve met with the other federations and none of them want humans in their galaxies. Your nature is too destructive. You’re on your own.”