Seed: Ghosts of Climates Past:
When we compare Earth with other planets, we see how easy it is for a planet to permanently lose a pleasant climate. Venus and Mars each started out with warm oceans and volcanoes, and the same carbonate thermostat that keeps Earth temperate was once also operating on our planetary siblings.
This article provides an excellent summary of how a planet uses carbon dioxide to regulate the surface temperatures.
As the sun slowly brightens over billions of years (by 30 percent so far over its lifetime), this thermostat gradually lowers the overall CO2 content of the atmosphere. Given enough time to respond to any provocation, our climate is stable.
There is more, the details of the methane/nitrogen based atmosphere on Titan the satellite of Saturn,
Chemically, Titan gives us a window into our organic origins, but climatically it presages our planet's ultimate fate. Such a transition is almost inevitable, more than a billion years hence, when the brightening sun overwhelms the cooling capacity of Earth's carbonate thermostat.