List of functional global warming terrain transformations?

[Camber]

I don't have answers for all of these, but I'll give the few I know.

I do know that when I gave 100 nukes to a test player and launched half of them into the sea, it made the global warming indicator go red. The player also had a couple of cities that were size 3, so I can't tell you what portion of the global warming was caused by the nukes. I can also tell you that at that point, on a small map, I had over 20 tiles transforming each turn (I had reveal map turned on). Some tests on the exact dynamics of these factors would be interesting.

It appears that clearing a forested Tundra or Plains tile will reveal Tundra or Plains underneath. But Hills, Jungle, Mountain, Volcano, and Wetlands all have Grasslands as the base underneath. Once a Forested Tundra or Forested Plains tile turns to one of these (Hills, Jungle, Mountain, Volcano, or Wetlands), I think you lose the Tundra or Plains properties of that tile permanently--the base is now Grasslands. Some confirmation tests would need to be made; I'm still a little fuzzy in my memory of whether or not Grasslands can be made to turn into Plains.

I had never heard before that you can assign the "clear wetlands" or "clear forest" jobs to Hill, Mountain, or Volcano terrain. But if it is true, it would undoubtedly result in a Grasslands tile, as this is the base for these types of terrain.

 

[KrikkitTwo]

I do remember testing a while back in which I found that
The Plains was not part of the "Grassland group" and

Desert and Flood Plains had a cycle of their own (where they could Terraform to each other with Desert counting as the Base Terrain for Flood plains...although, as I remember, it didn't work for Floodplains that actually bordered on a river)

I'd imagine the Water tiles might also be part of a group (although I'm not certain what Coastal Tiles that are actually coastal would do if set to change into Ocean or Sea..whether they would resist it, do it , or start eating into coastlines while doing it)

 

[DJ Bonebraker]

Well, In my Tweaked Out mod, I had Forest go to Rain Forests (in my mod, jungles were re-named rain forests and started as 1 food, 1 shield and 1 commerce (to represent the scientific breakthroughs from studying rainforest plants)), and rain forests go to grassland. In addition, I had tundra change to grassland.

In the course of a long playtest game where I was playing as the Ottomans, I was running my country with my usual put greenpeace to shame game style (I'd added an additional pollution reducing city improvement for the late industrial era, and I'd build all pollution reducing buildings before building a single factory or hospital), but the AI went with their typical slash & burn policies, so the sun was orange by 2000, and I personally witnessed grasslands changing into plains, plains into deserts, one of my forests (and my small empire had about 90% of the world's forest acreage) turned into a Rain forest, and one of my Rain Forests turned into a grassland. I've never seen whether or not the Tundra to grassland worked or not.

 

[KrikkitTwo]

Did some testing and here are results

Terrain change is only allowed in 3 ways [a series of Comprehensive tests in each I had starting nukes, 3x3 blocks of each terrain, including Forested Plains and Tundra, and would make All terrains globally warm to one type (except for the terrain itself which would warm to none)]

1. "Grassland group" (Grassland, Forest, Jungle, Marsh, Hill, Mountain, Volcano) The Base Terrain here is grassland and so these can be Chopped/Cleared into grassland, have Forest planted on them, and all Globally Warm to each other

2. Plains+Tundra are two parts of the Non-Grassland group that can be Forested, they Keep their Base Terrain. However, If they are forested, and the forest globally warms to another part of the grassland group, the base terrain changes. Also Forest can globally warm to either of them in which case the base terrain is changed...NOTE: even if the Base Terrain changes, the GRAPHICS of it don't change, so you can have a white grassland or a green tundra.

3. Desert, Floodplains, Desert is the Base Terrain for Floodplains (note this test was done without any rivers, so I think Rivers may Force the Desert to be Floodplain) but Desert CAN warm to Floodplain and non-river Floodplain can be Warmed, Cleared, or chopped to Desert

4. Water Tiles cannot terraform to or from anything (I didn't try 'Clearing/Chopping them' but no global warming transforms worked)


On actual rates
2 tests each had 100 pollution from cities (from a building), and a size 2000 map
1 had 2000 globally warmable squares Jungle<->Marsh interchangeable starting all jungle
The other had 25 Jungle and the rest of the map Plains (which were set to Warm to none)

It seems the chance of a square globally warming is determined for each square, because the block of 25 Jungle had 3 squares warm in ~200 turns, wheras the pure Jungle Map had about 121 including returns over 80 turns (about because that involved counting the global warming messages each turn)

This means that the chance of an individual square globally warming (not including Nuclear effects) is

(Total Pollution/Map Size)^2 *0.3

OR to put another way

Number of Squares that will globally warm / turn=
(Total Pollution^2)/Total Map Size * Fraction of squares on Map that will pollute * 0.3

(the 0.3 is an estimate it could probably be anywhere from 0.2 to 0.5 ..also in the first test I had 15 cities to be able to monitor all the Global Warming going on, but only one had the Polluting building)... Also the Sun was Yellow the whole time for both of those tests.

 

[Pounder]

Great work. Thanks alot for the effort. This is very useful info.

 

[WildWeazel]

Wow, it looks like we finally know basically how it works. Thanks Krikkitone

 

[KrikkitTwo]

Bit more Testing it seems the number of Squares that Transform in a turn are

(Pollution/Total Map squares)^2 * Pollutable Squares * 0.3
OR
% chance of a square polluting = (Pollution/Total Map squares)^2 * 30
I'm pretty sure that this determines the Sun Color

Nukes are permanent (or at least the color of the sun caused by nukes won't change for ~300 turns)...on a size 2000 map, 16 Nukes turned the sun light orange, 23 turned it dark orange and ~150 more than that didn't change the color.