How do i raise planetary temperatures?

[Gladaed (OP)]

With the departure of safe green house gasses what gas should be used instead? Which one could be usefull but is toxic?

[johiah]

Aestusium is what you are looking for.

[Droll]

but is toxic?

Obviously Carbon Dioxide if you want a poisonous one.
Aestusium might be better received by the citizenry though.

I cant remember its name but there is one like fusilirum or something that acts as safe anti-greenhouse gas. Check the Aurora Lore thread for the actual name but it should be obvious - look for the gas that doesn't exist irl.