What would happen to the convection currents in the mantle if earths interior cool down

If the earth’s interior cools down then the convection currents will not be produced in the mantle and geologically leads to dead earth.

Explanation:

Convection currents is the process by which the heated fluids will be made to float on the surface while the cooler fluids will get precipitated in the mantle. The high amount of heat in the earth's crust leads to transfer of them as magma on the surface of the mantle and then it will lose its energy and precipitate as tectonic plates.

So, convection currents leads to the movement and production of new tectonic plates. If the earth's interior gets cooled down, then the creation of convection currents will cease leading to a geologically dead earth.