Environmental Engineering Reference
In-Depth Information
TABLE 1.1 Continued
Higher temperatures/early snowmelt/early run-off in U.S.
Southwest
NA
Maurer et al., 2007;
Barnett et al., 2008;
Bonfils et al., 2008,
Hidalgo et al.,
2009; Pierce et al.,
2008
Arctic and Antarctic temperature increases; Arctic seaice
decrease; Arctic precipitation increase
NA
Gillett et al.,
2008a; Min et al.,
2008.
Increased atmospheric winter (JFM and JAS) storminess in high
latitudes
NA
Wang et al., 2009
SSTs warming in cyclogenesis regions of Atlantic and Pacific
oceans
NA
Gillett et al., 2008b
Increased ocean salinity in Atlantic Ocean
NA
Stott et al., 2008
NOTE: The degree of confidence is noted when available from the expert judgment by the IPCC AR4 authors.
More recent results (indicated by the light blue background) have appeared in the peer-review literature, but
their degree of confidence has not been assessed and thus does not appear in our table.
a
See Figure 9.16 of IPCC AR4 WG1 (Chapter 9).
b
Consistent with theoretical expectations of the effects of anthropogenic forcings but have not been
detected and/or attributed, due to modeling uncertainties or lack of skill, and poor quality/limited extent of the
data record.
1. a change in the system impacted is first associated with climatic
factors, and, separately,
2. the climatic factors are shown to be attributable to
anthropogenically caused changes.
In order to link the two steps formally, a measure of significant positive
spatial correlation between changes in the impacted system and changes
in climate was primarily used in the IPCC WG2 report to summarize many
studies of impacts all over the globe. This correlation-based argument was
also supported by the existence of several studies that performed formal
D&A through modeling of specific systems or domains, and, importantly,
by scientific understanding of the reasons why the impacts are consistent
with warming of the climate system.
In summary, most of the attribution of impacts that has taken place
thus far has relied on the documented attribution of the warming patterns
of the physical system coupled to the scientific understanding of the effects
of such warming on natural and human systems, together with significantly
