Why does heat generation cause global warming?

Can the Earth transfer heat to outer space?

If yes, what in outer space can receive heat from the Earth?

We know that there are three ways in heat transfer; conduction, convection and radiation. Conduction and convection are the transfer of heat from hot to cold substances. The Earth cannot transfer heat to outer space by conduction and convection, because there is no material in outer space around the Earth. Only radiation can remove heat from the Earth.