Complex sentence: This cooling is offset somewhat by the greenhouse effect of clouds which reduces the outgoing longwave radiation by about 31 W/m², so the net cloud forcing of the radiation budget is a loss of about 13 W/m² table 3.1.
Split into simpler sentences: This cooling is offset somewhat by the greenhouse effect of clouds which reduces the outgoing longwave radiation by about 31 W/m². Thus the net cloud forcing of the radiation budget is a loss of about 13 W/m² table 3.1.