Returning to the balcony, he luxuriated in the watery moonlight. The neighborhood was completely quiet this late at night, and the moon bathed the buildings and the ground in a milky, unreal, tender glow. He had the sensation of waking from a dream, or perhaps he was still dreaming.
The phone rang again. The screen showed another unfamiliar number, but as soon as he picked up, he recognized the voice of his future self. It was still distant and hollow, but the background noises were different.
“You succeeded,” his future self said.
“When are you calling from?” he asked.
“The year 2119.”
“So four years earlier than the last time you called.”
“For me, this is the first time I’ve ever called you… or calling me, I guess. But I do remember receiving that phone call you mentioned more than a hundred years ago.”
“That was just twenty minutes ago, for me. How is everything? Has the seawater receded?”
“There’s no seawater. The climate never warmed drastically, and sea levels didn’t rise. The history you heard about twenty minutes earlier never happened. In our history books, solar energy made a breakthrough in the early twenty-first century and culminated in the silicon plow, which made large-scale solar energy collection possible. In the 2020s, solar energy came to dominate world energy markets, and fossil fuels quickly vanished. The first half of your—our—life has been a brilliant rising arc tied to the silicon plow, and in three years from your time, the technology will begin to spread across the globe. However, just like the history of the coal and oil industries, the history of solar energy hasn’t generated any lasting celebrities, not even you.”
“I don’t care about being famous. It’s wonderful to have had a role in saving the world.”
“Of course we don’t care about fame. In fact, it’s good that we are not well known, otherwise we’d be treated as history’s greatest criminal. The world has changed, but not for the better. The good thing is that only one person, you and me, knows this. Even those who had devised and implemented the plan to interfere with history the last time have no memories of fossil fuel use in the rest of the twenty-first century since that timeline never came to be. I don’t remember calling you, but I do remember getting the call from the future. That phone call is, in fact, the only clue I have to that nonexistent history. Listen! What do you hear?”
Through the receiver, he detected faint cries that reminded him of clouds of swarming birds above the woods at dusk. Gusts of wind swept through the trees from time to time, overwhelming the cries with susurrations.
“I can’t tell what I’m hearing. It doesn’t sound like the ocean.”
“Of course it doesn’t sound like the ocean. Even the Huangpu River is almost dried out. This is the drought season—there are only two seasons now, drought and flood. It’s possible to cross the river just by rolling up your pant legs. In fact, several hundred thousand starving refugees have just crossed the river into Pudong, covering the riverbed like a mass of ants. The city is in disarray; I can see fires starting everywhere.”
“What happened? Solar energy should have the lowest environmental impact.”
“You’re sadly mistaken. Do you know how many square kilometers of monocrystalline silicon fields are necessary to supply the energy needs of a city like Shanghai? At least twenty times the area of Shanghai itself! During the century after your time, urbanization accelerated, and even a mid-sized city now is comparable to the Shanghai of your era. Starting in the 2020s, silicon plows transformed the face of every continent. After all the deserts had been turned into solar fields, they began to devour arable land and vegetation cover. Now, every continent is suffering from excessive siliconization. The process had advanced far faster than desertification. The land surface of the Earth is now almost entirely covered by silicon solar fields.”
“But this should be impossible under theories of economics! As land grows more scarce, the value of any unplowed land ought to rise, and silicon plows should become too expensive to be viable in the market—”
“This was no different from the history of the fossil fuel industries. By the time the conditions you describe came into play, it was too late. Shifting to alternative energy sources was no easy task, and even rebuilding the infrastructure for coal and oil required too much time. Meanwhile, the need for energy kept on growing, and silicon plows had to devour more land. Land siliconization was even more damaging to the environment than desertification. As conditions deteriorated, drought swept the globe, and the occasional rainfall only resulted in massive floods…”
Listening to this voice from a century in the future, he felt like a drowning man. Just before he was about to give up all hope, he found himself somehow at the surface. Taking a deep breath, he said to his future self, “But there is a way out! A way out! It’s simple. I haven’t done anything yet except decide on a plan for how to introduce the technology. I’ll immediately delete the email and all attachments, and go on with my life as before.”
“Then Shanghai will once more be swallowed by the sea.”
He moaned with frustration.
“We have to interfere with history again,” said his future self.
“Don’t tell me: you’re going to give me some other new energy technology?”
“That’s right. The key to the new technology is ultra-deep drilling.”
“Drilling? But the technology for oil extraction is already very advanced.”
“No, I’m not talking about drilling for oil. The wells I have in mind will reach a depth of over a hundred kilometers, penetrating the Mohorovičić discontinuity and boring into the liquid mantle. The Earth’s powerful magnetic field is generated by strong electric currents deep within the planet, and we want to tap into them. Once the ultra-deep wells are drilled, massive terminals dropped into the wells will extract the geoelectric energy. We’ll also give you the technology for electrical terminals that can function under such high temperatures.”
“That sounds… grandiose. I’m rather frightened.”
“Listen, geoelectricity extraction is the greenest technology. It doesn’t take up any land and doesn’t generate any carbon dioxide or other pollutants. All right, it’s time to say goodbye. If we ever talk again, let’s hope it’s not to save the world…. Go check your email.”
“Wait! Let’s chat some more. Tell me about… our life.”
“We have to keep contact with the past to a minimum to reduce information leakage. I’m sure you understand that what we’re doing is incredibly dangerous. Also, there’s nothing to talk about really, since whatever I’ve gone through you’ll get to experience sooner or later.” The connection ended as soon as his future self stopped talking.
He returned to his computer and saw a second email. Like the last one, it was also packed with technical information. As he browsed through the attachments, he found that ultra-deep drilling used lasers instead of mechanical bits, and the molten rock was channeled up through the drill to the surface. The last attachment was another photograph of an open field studded with high-voltage transmission towers. The lattice towers looked slender and light, perhaps constructed from some strong composite material. One end of the wires plunged into the earth, evidently to tap into the buried geoelectric terminals. The ground itself attracted his gaze, as it was the lifeless dark color of plowed silicon fields. A network of fencing divided the ground into a grid, which he decided must be transmission lines that extracted the energy from the monocrystalline silicon. Unlike the photograph from the last time, the sky was a clear azure, with not a wisp of cloud to be seen. This was an age where rain was rare, and even through the photograph he could feel the crisp, dry air.