Two special features in particular make mosses an important ally in the fight against global warming: air purification and cooling. If a particular moss is found in a place, then that says something about the components of the air in that place. And if no moss is growing, that means something, too. Some mosses use the ammonia from car exhaust as a nutrient. Others bind and metabolize heavy metals or fine dust.
And mosses are little sponges. Since they draw water only from the air, they do well to absorb and store a lot of moisture. Sphagnum moss, for example, can absorb 26 times its dry weight in water. Via evaporation, a considerable cooling of the air is generated. Anyone who has taken a break in a mossy forest clearing in summer knows this refreshing effect.