Carbonyl sulfide: a new tool for understanding the response of the land biosphere to climate change.

The global climate is changing mostly because of the
anthropogenic emission of greenhouse gases, especially
CO2, into the atmosphere. The rate of atmospheric CO2
growth in the future will depend on the balance between
emissions and sink strengths. The importance of land
photosynthesis in dampening the CO2 increase in the
atmosphere is now well recognized and both climate and
global carbon (C) models incorporate photosynthesis-
climate feedbacks. However, we still lack robust tools for
partitioning different component fluxes (e.g. photosynthesis,
respiration, decomposition) and for assessing the effects
of climate change and atmospheric CO2 increase on the
C-sequestration potential of the biosphere. The paper by
Stimler and coworkers in this issue of New Phytologist (pp.
869-878) shows that carbonyl sulfide (COS) represents a
useful tracer of gross photosynthesis. This offers the
perspective of an additional independent tool to study the
terrestrial C cycle and to investigate ecosystem responses
to global change.