Aurora v1.12.0 Patch Notes - October 11th 2020

Change to Greenhouse Gas and Dust Mechanics

The new mechanics for the effect of greenhouses gases and dust on temperature are calculated using the following formulae:

Greenhouse Factor = 1 + (Atmospheric Pressure / 10) + Pressure of Greenhouse Gases
If Greenhouse Factor > 3 Then Greenhouse Factor = 3

Anti-Greenhouse Factor = 1 + (Dust Level / 20000) + Pressure of Anti-Greenhouse Gases
If Anti-Greenhouse Factor > 3 Then Anti-Greenhouse Factor = 3

Surface Temperature (K) = (Base Temperature (K) * Greenhouse Factor * Albedo) / Anti-Greenhouse Factor

Note
*This change was made because in v1.11, anti-greenhouse pressure is deducted from greenhouse gas pressure. However, this gives anti-greenhouse gas a potentially much greater impact than greenhouse gas. For example, assume a planet with no atmosphere to which is added 1 atm of anti-greenhouse gas. The calculation would be:

Greenhouse Factor = 1 + (1/10) -1 = 0.1

In other words, 1 atm of greenhouse gas would reduce the temperature to just 10% of the base temp. Adding 1.2 atm would reduce temp below 0K. The root cause of this problem is that temperature has a minimum value (0K) but no maximum. The new mechanics avoid this by making anti-greenhouse gases a divisor, rather than a subtraction. As dust is effectively a temporary anti-greenhouse gas, it makes sense to treat it as such for the new mechanics. However, that doesn’t mean that terraformers can remove dust.*