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Australia: The Land Where Time Began |
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Climate
Sensitivity to Cumulative Carbon Emissions Due to Ocean Heat and Carbon
Uptake It has been shown by climate model experiments that
transient global warming is nearly proportional to cumulative carbon
emissions on timescales that are multi-decadal to millennial (Matthews
et al., 2009; Allen et
al.,
2009; Zickfield et
al., 2009;
Zickfield et
al., 2013;
Gillet, Arora, Matthews & Allen, 2013). It is, however, not
quantitatively understood how this near-linear dependence between
warming and carbon emissions arises in transient climate simulations
(IPCC, Climate Change 2013; Collins et al., 2013). In this paper
Goodwin, Williams & Ridgwell present an equation that is theoretically
derived of the dependence of global warming on cumulative carbon
emissions over time. Their analysis, for an atmosphere-ocean system, has
identified a surface warming response to cumulative carbon emissions of
1.5 ± 0.7 K per 1,000 Pg of carbon that is emitted. By the end of the
century and beyond this surface warming response is reduced by typically
by 10-20 %. As a result of partially opposing effects of the uptake by
the ocean of heat and carbon, the climate response remains nearly
constant on multi-decadal to millennial timescales (Solomon et al.,
2009), the warming that results then becoming proportional to cumulative
carbon emissions after many centuries, as pointed out earlier (Williams
et al., 2012). When estimates of the uptake of terrestrial carbon are
incorporated (Friedlingstein et al., 2006), the surface warming response
is reduced to 1.1 ± 0.5 K per 1,000 Pg of carbon that is emitted, though
Goodwin, Williams & Ridgwell suggest it is not likely this modification
will significantly affect the way in which the climate response changes
over time. Goodwin, Williams & Ridgwell suggest their theoretical
framework may be used in climate models to diagnose and mechanistically
understand the differences between their projections.
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Author: M.H.Monroe Email: admin@austhrutime.com Sources & Further reading |