There are many counteracting natural processes on Earth that keep the climate relatively stable in all directions. For instance, oceans can just absorb quite a large amount of CO2, thus preventing a greenhouse gas effect from occurring in the atmosphere. Polar icecaps also melt and that absorbs a huge amount of energy, stabilizing the temperature.
Eventually, many of these processes become depleted and global average temperature starts to rise.
Eventually, many of these processes become depleted and global average temperature starts to rise.