The reason for the acceleration is because most of the greeh house gas emissions (CO2, CH4 etc) once emitted will stay in the atmosphere for a very long time (100s of years, they accumulate). PLus we are emitting these at a much faster pace than they can be removed from the atmosphere by natural processes (we rely on nature because currently, we do not have technologies to remove GHGs from the atmosphere at scale economically). So it has a compounding effect in terms of temperature response over time...
Have tried to share some thoughts on this here, have a look if you like