Geoscience Reference
In-Depth Information
to global warming through consideration of both direct and
indirect impacts of climate change on microorganisms, and the
capacity for such effects to amplify or dampen carbon cycle
feedbacks. This is a major challenge, but we believe that prog-
ress can be made through the use of long-term multifactor field
experiments in relevant biomes, which incorporate consider-
ation of direct and indirect impacts of climate change on soil
microbes and their contribution to land-atmosphere carbon
exchange, measured at the whole ecosystem scale. Such stud-
ies require a collaborative approach to link microbial ecology
to the whole ecosystem-scale flux measures and modelling of
carbon cycle feedbacks.
There is a consensus among scientists that global climate
change is happening and that the increases in global aver-
age temperatures since 1900 can be largely attributed to
human activities. However, there remains much uncertainty
about predictions of future greenhouse gas emissions and the
response of these emissions to further changes in the global
climate and atmospheric composition. To help tackle this
uncertainty, there is a need to better understand terrestrial
microbial feedback responses and the potential to manage
microbial systems for the mitigation of climate change. There
is an urgent need to improve the mechanistic understanding of
microbial control of greenhouse gas emissions and the inter-
actions between the different abiotic and biotic components
that regulate them. This understanding will help to remove
large uncertainties about the prediction of feedback responses
of microorganisms to climate change and will enable the
knowledge to be incorporated into future models of climate
change and terrestrial feedbacks.
It is currently difficult to know whether changes in processes
that are associated with climate change are brought about by
the effect of climate change on soil microbial communities, by
changes in soil abiotic factors or by interactions between the two.
Moreover, it is unclear how microorganisms respond to climate
change and therefore what their potential is to influence climate
feedbacks across ecosystems and along environmental gradi-
ents. Another issue that needs to be taken into consideration
is that, to date, most studies have focused on one greenhouse
gas, whereas evidence suggests that microorganism-mediated
fluxes of different greenhouse gases respond differently to cli-
mate change. For example, it is assumed that conservation of
peatland will enhance carbon sequestration, but this may also
increase CH
4
fluxes, so the effect on net greenhouse gas flux is
still unclear Woodward et al. (2004).
