IMPACTS OF CLIMATE CHANGE ON WORLD WIDE WATER AVAILABILITY

1. TERM PAPER PRESENTATION
ON
“CLIMATE CHANGE AND GLOBAL
WATER RESOURCES”
SHYAM MOHAN CHAUDHARY
17AG62R13
Land and Water Resources Engineering
Agricultural and Food Engineering Department
IIT KHARAGPUR

2. CONTENTS
• INTRODUCTION
• HISTORICAL PERSPECTIVES• HISTORICAL PERSPECTIVES
• METHODOLOGY
• CURRENT STATUS & FUTURE SCOPE

3. INTRODUCTION
• Few years ago, climate change was just an
opinion with no significant proofs.
• Some harbingers to climate change were :
– Spreading of diseases like malaria, dengue,– Spreading of diseases like malaria, dengue,
cholera etc.
– Changes in flora and fauna population
– Heavy downpours, flooding, droughts and forest
fires in some places across the globe.

4. Evidences of climate change
Global temperature Glacier meltingGlobal temperature
rise
Glacier melting Ocean warming
Ocean acidification Severe droughts Severe floods

5. What will climate change do…..??
• Climate change will not change the existing
volume of H2O globally, but changes will be in its
form and quality in an unwanted manner which
may become a cause of future casualties.may become a cause of future casualties.
• Quantitative estimates of changes in major long
term climatic variables such as air temperature,
precipitation etc. are needed in order to provide
reliable forecasts of water availability.

6. HISTORICAL PERSPECTIVES
• AAAS panel on Climate Change in 1990
200% increase in
CO2 concentration
20% change
in rainfall
50 % change
in soil moisture

7. (Rosenberg et al., 1990) found that increase in CO2
concentration will increase stomatal resistance thus
decreasing transpiration.
If CO2 concentration
is doubled
Global transpiration
will get halved
result

8. Keynotes from the Fifth assessment report of IPCC, 2014
A warming of 0.65 to 1.06°C in land and ocean surface
temperature for the period 1880 to 2012.
Between 1971 to 2010 about 90% of energy has been
stored in oceans.
From 1971 to 2009, global rate of glacier melting ranged
from 91 to 361 Gt/yr and from 1993 to 2009 it ranged from
140 to 410 Gt/yr.
The radiative forcing due to human activities for the year
2011 ranged from 1.13 to 3.33 W m−2 which is 43% higher
than in 2005.

9. The concentration of the greenhouse gases in the
atmosphere after industrialization has increased by
150% (methane), 40% (carbon dioxide), 20% (nitrous
oxide) due to human activities. In 2011, concentration
of these gases was as CO2 (391 ppm), CH4 (1803 ppb)
and N2O (324 ppb).

10. METHODOLOGY
• For predicting climate globally generally GCMs
(General Circulation Models) are used.
• GCMs are mathematical climatic models
which use the Navier Stokes Equation onwhich use the Navier Stokes Equation on
rotating sphere to simulate general circulation
of dynamic atmosphere and ocean.
• Outputs from GCMs are input to any
hydrological model to simulate water cycle
components.

11. Use of GCMs to predict future climate
• Inputs to GCMs are SSTs (sea surface
temperatures). These inputs represent the four
initial conditions (members) and one ensembled
mean condition.mean condition.
• To generate some future climatic scenarios, each
model simulation runs under scenarios like SRES,
RCPs

12. Model calibration and validation
• Parameters involved in GCMs are cloud fraction,
albedo, land surface processes etc.
• Test procedure used for calibration and• Test procedure used for calibration and
validation can be
– Split sample test.
– Differential split sample test.
– Proxy catchment differential split sample test.

13. Outputs as Inputs … then results
• Outputs obtained from GCMs are future
predicted values of precipitation,
temperature, relative humidity, wind speed
etc. as time series.etc. as time series.
• Output is then used as input to hydrological
model which then simulates components like
runoff, ET, snowfall etc. which is then used to
assess water availability in future.

14. Current status and future scope
• Since the GCMs work at very low resolutions, RCMs
(regional climate models) are in use but these
models require very high computational
requirements.
• Climate modeling is implementing a major focus on
the actions of aerosols on climate and also focus on
the processes which lead to ozone layer depletion
using ESMs (Earth system Models)
• Now some models have also started making efforts
to represent air and water quality.

15. # unavoidable facts
• WMO in Paris Climate Agreement on 30th Oct 2017,
stated that, “CO2 in atmosphere up 145% over pre-
industrialization (403.3 ppm in 2016), methane up by
257% since 1750 and N2O up by 122%”.
• The amount of CO2 in the atmosphere has become so
high that even planting trees can NOT save us because
there is not that space available on earth to plant the
number of trees it would take to prevent the climate
from warming at current rate.
- source: European Commission Climate Action

16. THANK YOU