Geoscience Reference
In-Depth Information
role of information on observed changes in climate and the effects of past
climate change in natural the NSS;
causes of change considering both natural and anthropogenic drivers of climate
change;
future climate change and its impacts;
adaptation and mitigation options and responses related with sustainable
development;
the long-term perspectives and analyses scienti
c, technical and socio-economic
aspects relevant to adaptation and mitigation; and
robust
findings and key uncertainties.
Analysis of the observational data as contained in TAR led to the conclusion that
global climate change is taking place. The Reports IPCC (2001, 2005, 2007) give a
detailed review of the observational data of the spatial-temporal variability of the
concentrations of various GHGs and aerosols in the atmosphere. The adequacy of
numerical models was discussed from the viewpoint of the climate-forming factors
and the usefulness of models to predict climate change in the future. The main
conclusion about anthropogenic impacts on climate was that
there is new and
stronger evidence that most of the warming observed during the last 50 years has
been determined by human activity
“
”
. According to all prognostic estimates con-
sidered in TAR, both surface air temperature (SAT) increase and sea level rise
should take place during the 21st century.
When characterizing the IPCC data for the empirical diagnostics of climate,
Folland et al. (2002) drew attention to the uncertainty of the definitions of some
basic concepts. According to IPCC terminology, climate changes are statistically
substantial variations of an average state or its variability, whose stability is pre-
served for long time periods (for decades and longer). Climate changes can be
natural in origin (connected both with internal processes and external impacts) and/
or may be determined by anthropogenic factors, such as changes in the atmospheric
composition or land use. This de
nition differs from that suggested in the Frame-
work Climate Change Convention (FCCC), where climate changes are only of
anthropogenic origin, in contrast to natural climate change. In accordance with the
IPCC terminology, climatic variability means variations of the average state and
other statistical characteristics (MSD, repeatability of extreme events, etc.) of cli-
mate on every temporal and spatial scale, beyond individual weather phenomena.
Hence, climate variability can be both of natural (due to internal processes and
external forcings) and anthropogenic origin: possess both of internal and external
variability. As Folland et al. (2002) have noted, seven key questions are most
important for the diagnostics of observed changes and the climate variability:
(1) How signi
cant is climate warming?
(2)
cant?
(3) How rapidly has the climate changed in the distant past?
(4) Have precipitation and atmospheric water content changed?
(5) Do changes in the general circulation of the atmosphere and ocean take place?
Is currently observed warming signi
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