ok, so far.. there appear to be at least two angles.. One is the factual measure of the role of carbon in various forests over time; the second is as a target for collective action.
Deforestation and forest fire are certainly significant sources of carbon emissions. Not all carbon goes into the atmosphere, however. Given current conditions and human practices, acting now to prevent deforestation and catastrophic forest fire are significant in themselves. Forests and managed forests are an important source of food and trade goods for humans worldwide. Mangrove forests are a topic in themselves.
In IPCC_SRCCL_2019/IPCC_SRCCL_05_Chapter-2:
Global models and national GHG inventories use different
methods to estimate anthropogenic CO2 emissions and
removals for the land sector. Consideration of differences in methods can enhance understanding of land sector net emission such as under the Paris Agreement’s global stocktake (medium confidence). Both models and inventories produce estimates that are in close agreement for land-use change involving forest (e.g., deforestation, afforestation), and differ for managed forest. ...
The gross emissions from AFOLU (one-third of total global emissions) are more indicative of mitigation potential
of reduced deforestation than the global net emissions
(13% of total global emissions), which include compensating deforestation and afforestation fluxes (high confidence). The net flux of CO2 from AFOLU is composed of two opposing gross fluxes:
(i) gross emissions (20 GtCO2 yr–1) from deforestation, cultivation of soils and oxidation of wood products, and (ii) gross removals (–14 GtCO2 yr–1), largely from forest growth following wood harvest and agricultural abandonment (medium confidence). {2.3.1}
Land is a net source of CH4 ... emissions for the 2006–2017 period (medium confidence). The pause in the rise of atmospheric CH4 concentrations between 2000 and 2006 and the subsequent renewed increase appear to be partially associated with land use and land use change. The recent depletion trend of the 13C isotope in the atmosphere indicates that higher biogenic sources explain part of the current CH4 increase and that biogenic sources make up a larger proportion of the source mix than they did before 2000 (high confidence).
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"Terrestrial greenhouse gas fluxes on unmanaged
and managed lands Agriculture, forestry and other land use (AFOLU) is a significant net source of GHG emissions (high confidence), contributing to about 23% of anthropogenic emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) combined as CO2 equivalents in 2007–2016 (medium confidence). AFOLU results in both emissions and removals of CO2, CH4 and N2O to and from the atmosphere (high confidence). These fluxes are affected simultaneously by natural and human drivers, making it difficult to separate natural from anthropogenic fluxes (very high confidence). {2.3} The total net land-atmosphere flux of CO2 on both managed and unmanaged lands very likely provided a global net removal from 2007 to 2016 according to models (-6.0 ± 3.7 GtCO2 yr–1)"