A sink does not have to be an "ultimate sink", you can think of it as a temporary storage subsystem. Individual trees take carbon from the atmosphere, put it in

A sink does not have to be an "ultimate sink", you can think of it as a temporary storage subsystem. Individual trees take carbon from the atmosphere, put it into their body mass, and release it years/decades later on their eventual death. As others have pointed out, a "steady state" forest would be carbon neutral. In any given year all the surviving trees add as much body mass as that of the fewer dying trees. However, steady state is usually not how things work out in practice. AFAIK, most years forest are carbon negative - slowly building up wood mass - and then there are specific events that make for big releases of carbon (big fires, blight that affects multiple trees, etc). Not sure if you can say that evens out to neutral in longer time frames. The problem in Brazil seems to be that illegal loggers are much more efficient than isolated release events for cutting down trees, so the normal tendency to sequester carbon is being overwhelmed. The "sink" in those terms gets turned into a "source". Not that new carbon atoms are getting created, but it's more like the buffer has now a tendency to grow smaller instead of bigger over time. btw. I don't understand why the down votes, so +1.