When the fleet of huge alien spaceships arrived in the solar system, the most surprising thing was that they ignored Earth for years, and focused on Mars.
For years scientists on Earth watched the spaceships with excitement, using high-powered telescopes. Some of the alien spaceships kept traveling back and forth between Mars and the moons of Jupiter. Some of the spaceships released smaller shuttle craft, and those craft then landed on Mars, later to return to the spaceships from which they had come. There was one network of traffic back and forth between Jupiter's moons and Mars, and another network of traffic back and forth between the surface of Mars and the spaceships orbiting Mars. Then scientists on Earth noticed that the spaceships were building giant mirrors in orbit around Mars.
A few years later the scientists noticed that the surface of Mars started to change dramatically. Much of Mars' frozen carbon dioxide started to melt. Scientists speculated that the giant mirrors were being used to beam solar energy at Mars, and that this was why the frozen carbon dioxide was melting. The melting of the frozen carbon dioxide produced a rise in the temperature of Mars, due to the same greenhouse effect that was happening on Earth to warm its temperatures.
When the latest United States space probe landed on Mars, it found that the surface was much warmer than it had been when previous space probes had landed. A few years later, scientists detected that liquid water had appeared on the surface of Mars.
The President of the United States called a meeting at the White House to discuss what was going on.
“What the hell are they up to?” asked the President.
“Apparently they are trying to terraform Mars,” said the President's chief science adviser. “They are trying to gradually make Mars more and more earth-like, to give it a higher temperature and surface water. They seem to be bringing various elements from the moons of Jupiter to Mars. The next step will probably be to introduce plant life. Once that gets going, the plants will release a lot of oxygen that will make the planet pretty much like ours.”
“Why do you think they want to do this?” asked the President. “Do you think they want to live on Mars?”
“I think we should assume the worst,” said General Jenkins, the head of the Joint Chiefs of Staff. “During World War II, do you remember what happened before D-Day? The United States spent years building up its forces in England, in preparation for an invasion of France. These aliens are probably doing something similar. They're probably using Mars as a great big staging area, as a place where they will build up their forces, to prepare for an invasion of Earth.”
“So we'll build up our forces to get ready for a fight,” said the President.
The alien activity on Mars intensified, and eventually astronomers noticed the first green specks on their photographs of Mars. Gradually more and more of the surface of Mars become the green color of vegetation and the blue color of liquid water. Anxiety about the intentions of the aliens grew even greater.
Then finally one day a large fleet of spaceships began traveling from Mars towards Earth. The spaceships went into orbit around Earth. Landing craft emerged from these spaceships, and the craft landed on the surface of Earth. From those landing crafts emerged robots, which began working on some form of construction.
“We need to destroy those things,” urged General Jenkins.
“All in good time,” said the President. “But let's wait a while to see what they're working on.”
After a few weeks it became clear what the alien robots were working on. They were building space elevators, gigantic devices for rapidly moving cargo or people from the surface of the Earth to an orbit in space, or the inverse. Once a space elevator was built, people could go from Earth into space without using a rocket, and could also come back from space to Earth without using any spacecraft.
“This confirms my suspicions,” said General Jenkins darkly. “They're building these space elevators so they can rapidly move an army from space to the surface of our planet. Once they're done with that, their invasion should begin. We have to destroy those space elevators.”
The President authorized an attack, and the US Air Force got busy assembling aircraft to be used for the bombings. But then an alien spacecraft landed in New York, in front of the United Nations building.
After three extraterrestrials emerged from the alien spacecraft, they were approached by the US ambassador to the UN.
“We know all about your plans for conquering us,” said the ambassador. “We will fight you with all our might.”
Then the largest of the extraterrestrials spoke.
“You are wrong,” he said in a strange, deep voice. “We are not here to destroy you. We are here to save you.”
Inside the UN Building the three aliens told the full story of why they had come from a distant star. Their race had discreetly visited the Earth years ago, and had found scientific proof that Earth was doomed to an ecological catastrophe that would make it unlivable. There was a huge amount of frozen methane in the Arctic and the tundras of Siberia. Global warming on Earth would cause that methane to melt. Being a greenhouse gas twenty times more dangerous than carbon dioxide, the methane would cause a super-acceleration of global warming, which would raise the planet's temperature to a level that would make the planet uninhabitable.
“We have been terraforming Mars so there could be a planet that your race could escape to,” explained the extraterrestrials, “after the temperatures on your planet grow too high.”
“And what about the space elevators?” asked the ambassador.
“They are not for bringing our people down to your planet,” said the extraterrestrial. “The space elevators are for bringing your people into space, so that we can take them to the newly habitable planet Mars.”
The news of the alien announcement spread around the globe. Commentators lamented that mankind had got itself into such a mess. Why had so many people continued to pursue high-consumption lifestyles with a high carbon footprint, long after the scientists had sounded the warning bells? If only people had lived more simply, with less waste and extravagance, the coming disaster could have been avoided.
For a while many did not believe the aliens. But soon the frozen methane in Siberia and the Arctic started to melt, causing temperatures around the world to skyrocket. It was just as the aliens had predicted. The governments of Earth embraced the alien plan for migrating humans to Mars.
Then the first people starting using the space elevators to go into orbit, where they would board the alien ships to go to Mars. But the space elevators did not have the capacity to take all those who needed to go. The US government estimated that only one tenth of Earth's population could be saved before the planet got too hot to support life.
A lottery system was set up to determine who would be allowed to go to safety on the new Mars, and who would have to stay and die on the quickly warming Earth.
After getting the bad news that they would have to stay on Earth, a group of very wealthy industrialists decided to form a lobbying group that might change this result. They hired Daniel Black, the most expensive and well-connected lobbyist in Washington D.C. With a suitcase of cash and a bag of gold, Black was able to gain a meeting with Peter Baker, an official at the White House.
Baker listened to Black's slick lobbying presentation on behalf of his wealthy clients.
“Well, I see the group of people you represent are very, very special,” said Baker. “I checked out twenty of them. Lots of big factory owners, and some incredibly successful people. Globe-trotting billionaires with huge, sprawling mansions, big fleets of cars, huge yachts, and private jets. Shades of Jay Gatsby and William Randolph Hearst.”
“They're just the type of super-successful people we'll need on Mars,” said Black. “So I'm sure you'll agree that we need to make a special exception to allow my clients to be part of the humans taken to Mars. What a waste to let them die when Earth gets too hot.”
“No way,” said Baker coldly. “The people you work for each put thousands of tons of carbon dioxide into the atmosphere, by wastefully pursuing extravagant high-consumption lifestyles. They've already helped to ruin one planet, and I'm not going to help them get their hands on another one. Tell your billionaire buddies: you've made your bed, now lie in it. Or should I say: fry in it.”