All of the global climate models incorporate albedo (reflectivity) of the planet.
James Lovelock wrote about 'Daisy World' in 1983 - a hypothetical self-regulating planet covered with growing flowers. He noted that if temperatures were to cool for whatever reason, darker flowers would have an advantage, their would be random mutations towards darker flowers, they would multiply faster, absorb more light, and the planet would ultimately become warmer. And if the planet became hotter, lighter or white flowers would be less prone to overheating, they would be selected for and breed faster than overheated dark flowers, and eventually the planet would reflect more light and be cooler.
Lovelock is all for re-forestation as best I understand, but he doesn't see that as more than a drop in the bucket compared to the massive geochemical changes we are subjecting the planet to. We are at the point where the Arctic region is ice free for much longer portion of the summer, and this means less light is being reflected back into space and more is being absorbed there... a thinner layer of ice reforms in winter, but the Arctic winters only get a few hours of indirect light - summer ice is the critical factor.
Wikipedia Page on Daisy World
Think about it, vegetated surfaces will create chemical energy from sunlight through photosynthesis. unvegetated surface (concrete, pavement or bare soil alike) will turn the sun's energy in to warmth/heat*. We all know how significant this can influence microclimate by experience, several degrees in temperature from a well vegetated area to a bare soil or concrete area.
Yes, plants tie some of the energy into a chemical form via photosynthesis (3 to 7%), and this energy is potential and not reactive until the plant material is burned or metabolized by other life forms. But most of the cooling comes from shade and evapotranspiration of water. With evaporation, the air temperature is reduced but the heat is still 'latent' in the atmosphere. On a local scale, that may not be an issue, but on a regional or global scale, it is very important. The 'effective temperature' is what is important to most life forms, 90 degrees F in the dry desert is very different from 90 degrees F in a moist tropical area (they have very different 'effective temperatures'). If the air is dry we can cool ourselves by sweating or misting and we benefit from the evaporation. If we raise the humidity for a larger area, we don't benefit the same way.
Vegetation is a partial solution, not a panacea. But many partial solutions are all that we have, they will have to do.