If there is a reduction in the scientific
research in uncertainty then it will stimulate the scientists to perform the
new scientific research. As it is difficult to define uncertainty and it is
also not easy to calculate the quantification of uncertainty. But there are
also some projections.
Followings are the summarized projections
about the climate change by the IPCC-ARA for the year 2100:
Ø It is projected that
there will be an increase in global mean average temperature on the earth
surface is between 1.1 and 29 degrees, according to the lowest projection in
greenhouse gas emission in 2100 and there will be an increase in global sea
level between 0.18-o.38m.
Ø But according to the
highest emission scenario it is projected that due to greenhouse gas emissions,
the increase in temperature of the globe will between 2.4-6.4 degrees and the
increase in mean sea level globally will between 0,26 and 0.59m.
Both of the above projections based on the
increase in temperature and due to the lower and higher scenario of greenhouse
gas emission and sea level increase is due to the melting of ice sheets in
Firstly, the uncertainty in increase in
temperature and sea level rise can be quantified by two model projections by
observing the situation. Second the greenhouse gas emission range shows
our knowledge about the emission of
greenhouse gases due to human activities. The dependence of greenhouse gas
emissions is on decision that happen outside the physical science realm. Third,
due to the rise in sea level there may be an uncertainty in projection that
there are the processes that are happening poorly in the climate models are
important and represented poorly or not represented.
Finally, Farber’s argument discussed
above represents a fourth evaluation of uncertainty, when he concludes that the
IPCC process increases the certainty of climate projections because its
completeness and openness reduces the possibility of fundamental flaws in the
conclusions of global warming. This type of judgment by people outside the
community of climate scientists is an important indicator of the robustness of
knowledge. It addresses, with a documented method of evaluation, whether
nonscientists who are users of the knowledge generated by the scientific
investigation of the Earth’s climate find the information convincing. These
distinct nuances of uncertainty just begin to span the spectrum of uncertainty
that both scientists and decision makers must face. This wider spectrum would
include, for instance, the uneven and inconsistent expression of uncertainty by
Sources of uncertainty in CMIP5
recent discussion on the source of uncertainity in climate projection by IPCC
AR5 (Fig. 11.8, section 220.127.116.11).
In which updates earlier analyses using CMIP3 (temperature, precipitation)
to the latest CMIP5 simulations. The main source of uncertainty depends on
time, variable and spatial scale.
three main sources of uncertainty in projections of climate are: future
emissions (scenario uncertainty, green), internal climate
variability (orange), and inter-model differences (blue).
Internal variability is roughly constant by time. And the other uncertainties
grow with time. But at different rates. Although there is no perfect way to
cleanly separate these uncertainties. And different methods have given similar
the discussion from CMIP5 are not much changed from CMIP3. For global
temperature, the spread between RCP scenarios is the dominant source of
uncertainty at the end of the century. But internal variability and inter-model
uncertainty are more important for the near-term. For the next decade and
internal variability is the main source of uncertainty. A small caveat is the
role of anthropogenic aerosols. In which are assumed to decline quite rapidly
in all RCPs in the next 20 years. And so this scenario uncertainty may be
smaller than it should be.
global temperature, the figures below show two different representations of
this information. Either as a ‘plume’ (Fig. 1) and as a fraction of the total
variance (Fig. 2).
picture can be very different for other variables and on regional spatial
scales. For example, for European winter temperatures, the more
importantvariability component is internal component (Fig. 2). And, for
European winter precipitation, scenario uncertainty is almost irrelevant.
Because the internal variability and inter-model differences are relatively
much larger (Fig. 3). In fact, for precipitation in all regions, of the RCP
scenario uncertainty is relatively small. When they compared to the other
sources of uncertainty.
key messages are that resolving inter-model differences could reduce
uncertainty significantly. But there is still a large irreducible uncertainty
due to climate variability in the near-term. And, particularly for temperature,
future emissions scenarios in the long-term.
1: The sources of uncertainty in global decadal temperature projections. Expressed
as a ‘plume’.with the relative contribution to the total uncertainty coloured
appropriately. The shaded regions represent 90% confidence intervals.
Sources of uncertainty in global decadal (top). And European decadal DJF
(bottom) temperatureprojections, expressed as a fraction of the total variance.
Uncertainties in Projecting Climate
Change Impacts in Marine Ecosystem:
change has major impacts on the marine ecosystem, accounting variations in
biogeochemical cycles, trophic levels species life history and their
distribution. These changes in return impacts the factors on which society
relies factors from they are provoked either negatively or positively on their
food webs and ecosystem. For instance it is assure that the roles of ocean in
generating food for humans and skin for carbon dioxide are changed because of
climate change and these changes have great impact on the results of
in an ecosystem the variations that matter are mainly biological components and
the way they responds as a result of variations in environment that is result
of climate changes. As if how fishery yield will be effected if any change in
temperature or pH occurs. In order to resolve this issue it is important to
combine oceanic components with models of special ecology, population dynamics
including their all food webs. As consequences the uncertainty obtained in
physical climate models is taken to ecological models.