It is known from a comparison of the natural and anthropogenic fluxes of sulfur
that the total amount of sulfur entering the atmosphere had doubled owing to
human activity, but it is not known yet what the impact will be.
What are the effects of increased levels of sulfate in precipitation?
How do the effects vary?
What is the role of sulfur in upland and tropical soils?
Are these soils a source or sink for trace sulfur gases?