All players start at 20 TR. This is your basic income and VPs. You increase it every time you terraform.
Terraform Rating (TR) is the measure of how much you have contributed to the terraforming process. Each time you raise the oxygen level, the temperature, or place an ocean tile, your TR increases by 1. Each step of TR is worth 1 VP at the end of the game. Additionally, the Terraforming Committee awards you income according to your TR. During the Production phase, gain M€ equal to your TR.