However the biomass is consumed - energy production or lawn fertilizer - the net result would appear to be (especially in the case of slow growing hardwoods) that hundreds of years of slowly grown dense wood have been consumed in the past few years.
Frankly, understanding the whole carbon cycle in forests is a little daunting. I do actually believe that for the sake of the environment, we should be returning a considerable amount of our cleared lands to forest biomes. In the coastal areas of Lake Michigan I am focussed on, there are some quite attractive parcels that are fundamentally second growth forest. These were clear-cut in the early 19th century from primordial forests of mixed hardwoods and evergreens. Then they spent decades - sometimes more than a century - as cattle pastures producing dairy products. This caused more rapid erosion on the Western banks of the Lake. As populations grew in the MidWest, these areas became more valuable as homesites - thus the second growth forests. Not enough of them - I'd prefer that we had a solid mile or so of forest around the lakes - but a fair amount.
Now for some speculation. The use of human wastes for fertilizers is a dangerous practice, as they contain traces of heavy metals and antibiotics and a whole slew of other substances. It is probably not a sound practice to use such wastes for the fertilization of food crops. Is there not an opportunity here to re-grow forests and replenish soil carbons from human-sourced fertilizers?
OTOH, we do produce things such as maple syrups and honey from forests, and I for one love such naturally flavored sugars. I don't know if it's a sound long term practice, but even if we only did so for a short while, we could give reforested areas a jump start with human fertilizers. Once we have a sustainable form of forestry going, we could use the wood ashes from energy production to amend the soils and stimulate continued growth.