In early 2076, a club of amateur astronomers pointed their telescopes at Venus and made an astonishing discovery, one so unexpected that they initially assumed their equipment was wrong. There was no mistake though: Venus was cooling at a rapid rate. The fact that the cooling had begun recently, was accelerating, and that there was no known natural explanation for the cooling, led them to one conclusion: it was caused by humans.
The outcry was immediate. Who would want to cool Venus? How had they done it? How had they managed to keep it secret for so long? And why hadn't the Venusian satellites, stations, and unmanned outposts spotted the cooling effect earlier?
The latter question was answered with a set of very thorough diagnostic tests run on all relevant scientific hardware on or near Venus. The tests uncovered an exceptionally elegant virus that had infected every single instrument, causing them to ignore or misreport spectra, radiation, and temperature change data. It's thought that the amateur astronomers were able to spot the cooling because their hardware was too old to be infected, and because they hadn't previously shown any interest in the planet.
Within days, brand-new flyers and landers were jury-rigged together from orbiting platforms. Descending through the thick Venusian atmosphere, they discovered clouds of tiny reflectors floating in the air and spreading over the surface. On its own, each reflector only increased the planet's albedo — its reflectivity of sunlight — by a minuscule amount, but in their billions they had a significant cooling effect.
Thankfully, the reflectors weren't self-replicating — a nightmare scenario bandied around by irresponsible pundits — but were instead produced by minifactories trundling around the surface, extracting silicates. I have a replica of one such minifactory here. It turned out that the minifactories were, in fact, self-replicating, but their comparatively large size and slow replication rate helped soothe fears.
The investigations widened amid concerns that the 'rogue terraformers' responsible for the cooling may have employed other strategies besides the reflectors. Researchers looked into whether anyone was currently manipulating the orbits of asteroids to introduce water and hydrogen to the planet (alarmingly, yes); growing tweaked organisms to remove carbon dioxide from the atmosphere (no, probably because they would be too unreliable); and deploying an enormous solar shade at the L1 point (no, much too obvious).
Multiple groups claimed responsibility, with the most credible being the Farronite biome, a group that had long experimented with rapid terraforming simulations and had the requisite engineering and AI know-how to pull something like this off. However, beyond their very curt statement ("Yes, we did it"), the Farronites provided no hints towards their motives. But they were very clear on one thing: they were intent on continuing their experiment.
There was little anyone could do to stop them, since Farronite was a self-sufficient asteroid biome. Sanctions wouldn't affect them. Military action was extremely dangerous and generally frowned-upon. Appeals to more capable AIs fell upon deaf ears. The sole remaining option was rooting out their various robot and AI agents. This proceeded reasonably well until like-minded groups joined with the Farronites in the terraforming effort, resulting in a rapidly proliferating battle of wits and bots in the Venusian area.
But what lay at the root of this oddly frantic urge to terraform our system's second planet? Professor Russell from the Echus Overlook Institute explains:
"Let's say you wanted to aggressively terraform Venus at the fastest possible pace. You'd need a few centuries before you reached a shirtsleeves environment, and you'd still be saddled with a day/night cycle lasting almost four months. Given that in the same amount of time you could construct millions of tailor-made biomes, it's fair to say that the Venusian terraforming effort was more ideological than practical.
"One school of thought was that the Farronites believed a total civilisational collapse was imminent, so it would be wise to have a second, backup planet available for humanity. Something with an atmosphere more reliable than biomes and more stable than Mars. In that respect, their actions almost seem prudent, although I'm sure most biomers and Martians would disagree.
"Another theory was that the Farronites would eventually try shifting Venus' orbit away from the Sun, almost as a practice run for moving Earth away in a couple of billion years’ time as the Sun grows old and expands. Frankly, this strikes me as extremely fanciful, and I'm sure that it would be shut down immediately due to the danger it would cause to other bodies in the system.
"The most intriguing theory to my mind is that the terraformation effort — at least in part — was an elaborate exercise to pull humanity's fragmented attention away from the solipsism of sims and virtual universes and back towards 'base reality'; a genuinely shocking event that concerned everyone but didn't involve any deaths.”
If that's what the Farronites had in mind, they failed. After just a few months, the terraforming ‘war’ had devolved into a fairly pointless detente with neither the pro- nor anti-terraformers getting anywhere, and most people simply stopped paying attention. But even today, the Farronites continue their efforts. They seem intent on winning the argument by virtue of outlasting everyone else.