Climate Change UnderGround Cynthia Valle

1
Climate Change UnderGroundCynthia Valle

• OUTLINE
• What is Climate Change?
• Where does Groundwater fall?
• How do GCMs contribute?
• What are there setbacks?
• How does regional modeling assist?

2
climate change global warminggreenhouse warming
Svante Arrhenius (1896) was first scientist to
study effect of increased CO2 on surface
Temperatures.
3
GLOBAL CIRCULATION MODELS

• Formulated to simulate climate sensitivity to
  increased concentrations of greenhouse gases,
  primarily carbon dioxide .

4
GCM Predictions

• Precipitation by 2080s
• Increases in Winter Precipitation, 15 to 62
• Divergence in Summer Precipitation, -36 to 54
• Precipitation Extremes during late Summer
  through Winter
• Evaporation by 2080s
• Increases in Winter by 3 to 9
• Increases in Summer by 5 to 16
• Temperature by 2080s
• Increase of 2-4 degrees Celsius

5
UnEqual Distribution of Climate Changes Effects

• Areas where precipitation unaffected
• Increased evapotranspiration
• Reduced watershed yields.
• In Tropical Latitudes, mean temperatures will
  remain relatively high and uniform throughout the
  year
• water resources will not be affected due to the
  assumption of increased hurricane activity.

6
FEEDBACKS

• GCM predictions based on feedbacks
• derived from simulations

7
Cloud

• Global mean net cloud forcing -16 Wm-2
• Negative Forcing
• Causing a 10ºC to 15ºC cooling effect at surface
• Doubling CO2 to 600 ppm
• Positive Forcing 4 Wm-2
• 2ºC to 4ºC increase in surface temperature
• Cloud Cover Reduction

8
Surface Albedo

• Warmer Climates
• - Melting of Ice
• - Lower Planetary mean Albedo
• - Increase in Incoming Solar Radiation
• - Increase in Surface Temperature.

9
Vegetation

• Plant Growth and Respiration critically depends
  on atmospheric and land variables
• CO2 Concentrations, Temperature
• Soil Moisture
• Warmer Climates Causes
• Change in Vegetation
• Rise in Surface Albedo

10
Ocean-Atmosphere

• Warmer Climate
• - Increased Precipitation
• - Greater Fresh-Sea Water Mixing
• - Lower Ocean Density
• - Decreased Ocean Circulation
• - Decrease in Temperatures
• at High Latitudes
• - Decreased Evaporation
• - Reduced Salinity

(Loaiciga et al, 1995)
11
Soil Moisture
(Loaiciga et al, 1995)
12
GCM Uncertainties

• Miscomprehension of how systems are coupled
• Future GHG emissions and conversion to
  atmospheric concentrations
• Too Simplistic in Parametrization
• e.g. Cloud Feedback Not address possible
  diurnal/seasonal cloud shifts, changes in
  latitudinal cloud cover, cloud cover shifts from
  albedo variations, changes in cloud optical
  thickness
• Difference in Measuring Scales of Atmosphere
  (days) and Oceans (up to 1000 yrs)

13
GCM Limitations

• Predictions can not be confirmed until mid 21st
  century since Climate is so Sensitive and
  Variable
• Affects are not Distributed Equally
• Lack of Data
• Leads to paleoclimatic reconstructions which
  allow for more uncertainity
• Buttefly Effect
• Anthropogenic Influences

14
Multi-Scale ModelingRegional Macro
Vorosmarty et al, 2000)
15
CLASP II

• Uses GCM outputs for watershed scale simulations
• Nests groundwater models (i.e. MODFLOW) within
  watershed scale system
• Allows for focus on aquifer-stream interaction in
  physically-based manner
• Classified as an aquifer-vegetation-atmosphere
  model
• Distinct from other Models
• Decadal Timescalecan study impacts of global
  climate change on watersheds
• Converted to represent Long-Term Groundwater
  Feedbacksappropriate to infer Groundwater
  Implications on Climate Change
• Done by Studying Change and Interaction between
  Water Table and Latent Heat Fluxes
• Must be Simplified to get long-term timescale

16
CLASP II Predictions
(York et al, 2001)
17
Compared to Other Simulations

• (York et al, 2001)
• Clasp II simulation including an aquifer compared
  to one excluding an aquifer, proves how
  groundwater has an effect on climate change
  and/or vice-a-versa.

18
CLASP II Limitations

• Characterizes atmosphere as a single column
• Denies horizontal heterogeneities
• Abundance of fixed variables
• Aquifer surface and base elevation, hydraulic
  conductivity, storage coefficient, and soil
  density and heat capacity
• Hydraulic head is set to be constant
• Homogeneous vegetation cover
• Climatic feedbacks may distort hydrological
  systems, in turn altering parametrization
• Limited to inaccuracies of the larger scale model

19
INDIRECT IMPACTSof Climate Change on Groundwater

• Melting of Ice Caps causes Sea Level Rise which
  leads to Seawater Intrusions
• Population Growth
• Land Use Efficiencies (Urbanization)
• Deforestation

20
STRESS TODAY
(Ranjan et al, 2006)
21
(Ranjan et al, 2006)
22
CONCLUSION

• Models having taken a multiple-scale approach by
  nesting a subgrid model within a GCM, allow for
  more realistic insight on how hydrological
  processes are affected as a function of
  climate change.
• Models also open our eyes to how much we have
  yet to understand about the interactions in
  coupled systems.

23
References

• Bloomfield, J.P., Williams, R.J., Gooddy, D.C.,
  Cape, J.N., and P. Guha. (2006) Impacts of
  climate change on the fate and behavior of
  pesticides in surface and groundwater- a UK
  perspective. Science of Total Environment 369,
  163-177.
• Holman, I.P. (2006) Climate change impacts on
  groundwater recharge- uncertainity, shortcomings,
  and the way forward? Hydrogeology Journal 14,
  637-647.
• Karl, T.R. and Kevin E. Trenberth. (2003) Modern
  climate change. Science 302, 1719-1723.
• Liang, X. and Zhenghui Xie. (2002) Important
  factors in land-atmosphere interactions surface
  generations and interactions between surface and
  groundwater. Global and Planetary Change 38,
  101-114.
• Loaiciga, H.A., Valdes, J.B., Vogel, R., Garvey,
  J., and Harry Scwarz. (1995) Global Warming and
  the hydrological cycle. Journal of Hydrology
  174, 83-127.
• Ranjan, P., Kazama, S., and Masaki Sawamoto.
  (2006) Effects of climate change on coastal fresh
  groundwater resources. Global Environmental
  Change 16, 388-399.
• Vorosmarty, C.J., Green, P., Salisbury, J., and
  Richard B. Lammers. (2000) Global water
  resources Vulnerability from climate change and
  population growth. Science 289, 284-288.
• Wilby, R.L., Whitehead, P.G., Wade, A.J.,
  Butterfield, D., Davis, R.J., and G. Watts.
  (2006) Integrated modeling of climate change
  impacts on water resources and quality in lowland
  catchment River Kennet, UK. Journal of
  Hydrology 330, 204-220.
• York, J.P., Person, M., Gutowski, W.J., and
  Thomas C. Winter. (2001) Putting aquifers into
  atmospheric simulation models an example from
  the Mill Creek Watershed, northeastern Kansas.
  Advances in Water Resources 25, 221-238.

24
? QUESTIONS ?