Weird pollution bug?

[jordissim]

I've been playing the Romans on Emperor level and expanded very aggressively over a customized earth with big continental plates. Now I dominate 4/5 of the landmass, I signed peace treaties with all other civilizations (4 remaining) and I'm concentrating on building the biggest empire I've ever built, while winning through reaching Alpha Centaury. I've got 44 cities with a total population of over 224,000,000, and my pollution production is zero.
And suddenly, I start getting polluted tiles all around each of my cities (which by now are about 31 in size, on average)!
Is it a bug, or is there a reason for this sudden change?
Now I'm forced to use Terraform every 3 turns to get rid of all the garbage at once, since most of my cities are fully grown and cannot support a Settler... and even with the "rework" trick, so much pollution is unmanageable anyway. So my best play till now has been completely spoilt by all this.
Someone with the same problem (and hopefully, a solution as well)?

 

[Valen]

Much has been written about the so-called pollution bug. The prevailing theory is the pollution is triggered when science reaches a certain level. Can you estimate your last scientific discovery when the pollution started?

 

[jordissim]

Much has been written about the so-called pollution bug. The prevailing theory is the pollution is triggered when science reaches a certain level. Can you estimate your last scientific discovery when the pollution started?

I was definitively in the high numbers of future tech, so it would make sense... Thanks a lot for your answer!

 

[Dack]

... pollution bug ...

Can you upload the current MAP & SVE file with the pollution bug?
I have a hypothesis about the pollution bug that I would like to test.
I would really appreciate the files. Thanks

 

[Tenochtitlan]

I think the pollution 'bug' has to do with over-population. Once you pass a certain population, you start getting pollution everywhere.

 

[Valen]

It's also interesting to note that the pollution bug strikes at different times depending on the difficulty level.
Future Tech 64 triggers pollution at Emperor.
At Prince, it's somewhere around Future Tech 216.
It has just occurred to me that it would be interesting to play at king level to determine when pollution strikes.
As far as I know, the pollution bug has never been observed at Warlord or Chieftan.

 

[jordissim]

It's also interesting to note that the pollution bug strikes at different times depending on the difficulty level.
Future Tech 64 triggers pollution at Emperor.
At Prince, it's somewhere around Future Tech 216.
It has just occurred to me that it would be interesting to play at king level to determine when pollution strikes.
As far as I know, the pollution bug has never been observed at Warlord or Chieftan.

In my gaame, the pollution bug only started around Future Tech 120' on Emperor, so I think it must be a combination of population AND tech. I've played games with a higher population and no bug, and since you say in your experience Future Tech 64 triggered it in your case, I think that would be the most reasonable explanation. Weirdest of all bugs for sure...

 

[InnateGamer]

I think you're more likely to get pollution the more tech you have, that's the basic assumption I always assumed.

 

[Valen]

Here is my test game for the King level. The last discovery was future tech 103. There has been no pollution so far, but I think the pollution bug has already been triggered.
If you leave the research rate at 0%, you make only one discovery and there will be no pollution. If you set the research rate up to 80%, you make several discoveries and pollution from cities showing no smokestacks starts after future tech 107 or 108.

So why do I think the pollution bug has already tripped? Any city showing any smokestacks at all has a very high probability of polluting - not just the 1 or 2 percent.
You can test this by occupying mountains in Herakleia, Utica and Sydney. Occupying plains in Las Vegas and Rhodes will push those cities over the edge.

 

[Valen]

Okay, I have experimented a little more. It appears that at King level, Future Tech 106 is the last safe discovery as long as no cities show any smokestacks. Cities showing no smokestacks but sitting right on the borderline will start polluting once you discover Future Tech 107.
As you continue making more discoveries, the pollution threshold gets lower. Eventually every city regardless of population, production, mass transit and recycling has the possibility of generating pollution.