This is a poor title because it reads as though it’s the dust that is emitting longwave radiative heating (“exerts … radiative heating”) which might imply less heat trapped in the atmosphere if it has more opportunity to be radiated back out, but the abstract says:

we show that scattering and absorption of longwave radiation by dust heats the planet by +0.25 ± 0.06 W m⁻² (90% confidence)

The dust is absorbing and scattering (reducing the amount of heat reflected back out of the atmosphere), not radiating.

Naturally