Deforestation still progressing even if there's none

[Korian]

I am new to the Gathering the Storm DLC and I've been doing some experiment with the deforestation mechanic on a pangea duel map where I previously beat the AI (with no city states).
As many of you know, planting trees do not impact the deforestation level at all but - even worse - the deforestation level is progressing no matter what.

- Here's the value at turn 252 and a region that will be reforested later
https://zupimages.net/viewer.php?id=23/22/l8g8.png
https://zupimages.net/viewer.php?id=23/22/vai4.jpg

- And here how it looks like at turn 261
https://zupimages.net/viewer.php?id=23/22/3y1i.jpg
https://zupimages.net/viewer.php?id=23/22/ycb6.png


Note : I am using the mod "Deforestation : more gradual and severe" that adds more stage names but it's technically the same.

As you can see The Co2 malus kicked off while I was reforesting approximately 20 tiles on this image (and even more in total) and not deleting a single wood/rainforest/marshland tile.
So unless there's a glitch somewhere or something I am missing, the deforestation value is actually not based on removed forest tiles but just on time, I suppose ?
Which I found quite disappointing honestly, I dunno if this could be changed in the future or with a mod

[sauluxville]

OP, I'd like to ask you - do you have the NFP pack? From your screenshots I'd guess not, because Deforestation in your screenshots seems to progress normally, I mean, from 0 to 25% and so on.

And yes, from my observations, Deforestation also seems to progress irrespective of forest and jungle cutting.

On top of that, NFP, being such a disaster DLC pack, wrecked the Deforestation formula further, namely the Apocalypse pack. Since its release, if you have it, even if you play with no modes enabled, Deforestation progression seems to be reversed, and as soon as it kicks in, it starts with the highest value, 50%, if no mods, then it goes to 30% and probably 10%, although subsequent values do not matter. As soon as it kicks in at 50%, the existing carbon footprint is also increased by that percentage retroactively, over a turn, meaning that next few sea rising stages may and do happen in further consecutive turns, meaning the world sinks just in a few turns after that, at least on Deity.

The mod you use makes this observation even easier, when I was using it, Deforestation kicked in and went from 0 to 100% in a turn, then progressed to 75%, 50% and so on.

[Korian]

No, I only have GTS and Rise and Fall. Damn this seems very broken indeed, if I'm understanding it correctly even with the NFP pack it kicks in regarding of the actual number of deforested tiles ? And the reversing is not due to any of the player's actions (including AI) ?

[plaguepenguin]

I don't pay much attention to this climate screen, so I am far from certain that this is the explanation for the game behavior here, but perhaps the problem is the higher CO2 per turn output between your first screenshot and the second.

Having the full complement of old growth forests preserved may only totally buffer CO2 output until its per turn output reaches a certain point, then it can no longer absorb enough of it to keep the CO2 from having its warming effects. The game may also calculate the total load of CO2 that the remaining forest land can successfully compensate as a cumulative quantity, so that even if the total per turn CO2 output had not increased, enough had accumulated between your first and your second screenshot to finally start the CO2 effects on climate. Had more forests been left undisturbed, the world would have had a higher tolerance for cumulative or per turn CO2 production before it exceeded the amount that forests could get rid of. The removal of the trees may have happened a long time ago, but it only gets counted as deforestation for climate change purposes after the CO2 load reaches a certain point.

Again, this is only a conjecture. I will start to pay more attention to these dynamics to see if the theory fits the facts of how the game works.

[SLG]

Exactly in the game deforestation is removal of forest, jungle and marsh. So it is not just jungle or forest. Also jungle/forest fires I believe count as deforestation.

[Korian]

Originally posted by SLGray:

Exactly in the game deforestation is removal of forest, jungle and marsh. So it is not just jungle or forest. Also jungle/forest fires I believe count as deforestation.

Yeah I know that, as I mentioned in the Original post : "As you can see (...) and not deleting a single wood/rainforest/marshland tile" and since I only have the GTS and Rise and Fall DLCs forest fires aren't a thing.

[Korian]

Originally posted by plaguepenguin:

I don't pay much attention to this climate screen, so (...)

Well, the outputs display are not the Co2/turn but the total of the Co2 released during the game. Between the two screenshots, I released 9 units of Co2, the rest is due to the 25% "bonus" from the level of deforestation change (139*1.25 = 173).
So I released a steady 1 unit of Co2 per turn, there was no change (which is the bare minimum besides zero so if forests can't buffer that, they can't buffer anything).


But relaunching my save, I've tried to go carbon neutral and see what happens in three cases scenarios :


- (T252 to 300) Doing absolutely nothing and just passing turns
"Surprisingly", nothing happens. Deforestation level and Co2 bonus stayed the same. So the deforestation level does not change with the number of turns.


- (Restarting at T261 of the last save) Just producing builders and planting trees on every possible tiles, and this happens :
https://zupimages.net/viewer.php?id=23/22/nhca.png

Is planting woods actually makes deforestation worse ? But the Co2 bonus did not budge even though the deforestation level rose so I tried one last thing


- (T288, In the continuity of scenario 2) Starting to produce Co2 again while keep on planting woods, and after a while this happens :
https://zupimages.net/viewer.php?id=23/22/fb9q.png


So it seems that planting woods somehow makes the deforestation level goes up (???) but the bonus only kicks in if the amount of Co2 reaches a certain value. At least that's the conclusion I've reached unless there's a flaw in my little experiment.

[Aachen]

Here’s one of the civfanatics threads[forums.civfanatics.com] discussing it, if you’re interested.

[plaguepenguin]

Originally posted by Aachen:

Here’s one of the civfanatics threads[forums.civfanatics.com] discussing it, if you’re interested.

From a quick read of the civfanatic thread, it seems that these experts agree that the effect of deforestaiton is typical of the game, in that the mechanics are not documented in any human language, so you have to rely on observation of game behavior plus examination of whatever coding of the game they have made public. I can't interpret code to save my life, and I try to end the game before climate change kicks in very hard, leaving me with limited observation of how it works.

That said, some of the experts in the thread conclude that the number of turns that have passed since CO2 production started figures into the equation that controls the size of the deforestation effect. I notice that the sequence of four screenshots of the world climate screen are taken at progressively more advanced turns. The first is turn 252, while the last is turn 305. If these screen shots are from the admirably empirical trial of the three scenarios, and if the experts are right about "number of turn since first CO2 emission in the game" factoring into the equation, then the experiment failed to control for that variable. That deforestation of 0% in the first screenshot could be attributed to it being only game turn 252, so not so many turns since the first CO2 emission in the game, while the 50% at turn 305 is due to it being 53 turns further beyond the first CO2 emission. There presumably are other variables in the equation, but they were swamped by the effect of "# of turns since first CO2 emission".

[Korian]

Originally posted by plaguepenguin:

That said, some of the experts in the thread conclude that the number of turns that have passed since CO2 production started figures into the equation that controls the size of the deforestation effect (...) the experts are right about "number of turn since first CO2 emission in the game" factoring into the equation, then the experiment failed to control for that variable.

Except that in the first scenario, I went from turn 252 to 300 and there was no change in deforestation at all AND I had already emited Co2 in the 3 scenarios as you can see in the screenshots. So this explanation doesn't seem to make sense either.

Or it does, because I believe there's also a bug with the climate UI that does not seem to update correctly (scenario 2). So maybe the number of turns since first emission is part of the right explanation, but there's no way to tell because if you just skip turns without emitting anything nothing will changed on the UI.

It is still a bit fuzzy but it seems that whenever Co2 value is enough to make the global temperature changed (e.g "+X.XX°C since classic era"), it also updates the deforestation value.
Guess I will have to do other experiments on another save to be sure.

[SLG]

Are you talking about just for your civilization? I believe that graph is for global deforestation.

[Korian]

No I'm talking about global deforestation, but since I'm the only one left on the map, it boils down to the same thing