# Presentation: 416915

## NASA VISION QUEST2010-2025: LONG-TERM CLIMATE

**LEAD: DAVID RIND (NASA/GISS)**
**C0-LEAD: RICHARD SOMERVILLE (UCSD)**
**TEAM MEMBERS**
**PETER GLEICK (PAC INST)****	****CHRIS MILLY (USGS)**
**DANIEL HILLEL (UMASS)****	****CYNTHIA ROSENZWEIG ****	****	****	****	****	****	****(NASA/GISS)**
**CHRIS KUMMEROW (CSU)****	****WALEED ABDALATI ****	****	****	****	****	****	****(NASA/HQTR)**

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## WHAT IS THE FUTURE OF WATER RESOURCES, IN THE U. S. AND THE WORLD?

**Water**** is an  essential resource whose disruption will impact the economy, the quality of human life, and the fate of the environment for both natural and managed ecosystems.**

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## POPULATION PRESSURE ALREADY PRODUCES WATER PROBLEMS

**ALREADY SUFFERING**: **Algeria, Kenya, Rwanda, Tunisia and many in the Middle East**
**WILL LIKELY SUFFER: Egypt, South Africa, Iran, Somalia and Ethiopia, among others.**
**IN THE U.S.: Conflicts among states in the SW, SE, NE**

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## Scenes like these from Africa and Afghanistan may become more common in the future.

- Afghanistan

- Somalia

- West Africa

- Kenya

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## CLIMATE CHANGE WILL FURTHER ALTER WATER AVAILABILITY 

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**CLIMATE CHANGE WILL FURTHER ALTER WATER AVAILABILITY **

**E.G., INCREASED EVAPORATION, HEAVIER RAINFALL, MELTING GLACIERS**

## Dust Bowl Analogs?   

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**Dust Bowl Analogs?   **

**Composite maps of actual and tree-ring reconstructed “Dust Bowl” years (a-b) and four possible past analogs (c-f) since A.D. 1500.  None of the past analogs are as severe as the 20th Century event, and only one wet inverse of the “Dust Bowl” (right plot) is suggested in the data. **

**Source: Cook, Purdy, and  Gatewood, 2001**

- 1761-1768

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**Frequency of severe drought (occurring once every 20 years) using the Palmer Drought Severity Index (PDSI) for the 2xCO2 climate.  Results are from the NASA/GISS model (left) as well as the Geophysical Fluid Dynamics (GFDL) Model (right).  For the current climate (not shown), all the grid boxes are green (5%); for the future climate, the frequency of occurrence increases dramatically, as can also be seen by the graph of percentage occurrences of severe drought (bottom) in the two models.**

## WATER RESOURCE CHANGES WILL IMPACT SOCIETY

**ENERGY**
**POPULATED FLOOD PLAINS**
**HEALTH IN AN AGING POPULATION**
**AGRICULTURE **
**WATER EXTREMES MAKE THINGS ****	****WORSE**

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## Percent of the continental USA with a much above normal proportion of total annual precipitation from 1-day extreme events (more than 2 inches or 50.8mm)

**Karl *****et al*****. 1996**

**BW 7**

- KARL ET AL., 1996

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## CURRENT STATUS

**Need global hydrologic components on a local level**
**Predicting areas at risk is currently impossible**
**Climate models disagree**
**Impact models disagree with climate models**

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## Precipitation change projections are inconsistent. 

**Precipitation change projections are inconsistent. **

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## Soil moisture change projections are uncertain.

**Soil moisture change projections are uncertain.**

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## Without the optimistic assumption of full CO2 fertilization (bottom) even the U.S. suffers from the effect of water stress on agricultural production (top), but 3rd World countries are most affected.

- Source:
- Rosenzweig
- and Parry
- 1992

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## Changes in Runoff by Hydrologic Region, Using Two GCM Model Results

**Changes in Runoff by Hydrologic Region, Using Two GCM Model Results**

**Source: Wolock and McCabe (1999)**

**The discrepancies in forecast runoff changes over the U.S. make regional predictions and impacts uncertain.**** **

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## WHY NASA?

- A GLOBAL PROBLEM
**HYDROLOGIC CYCLE GLOBALLY CONNECTED (E.G., EL NINO)**
**IMPACTS ARE GLOBAL AND AFFECT U.S.**
**GLOBAL GEOPOLITICAL INSTABILITIES**
- REQUIRES A GLOBAL SOLUTION
**REMOTE SENSING**

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## S

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## GPM: Constellation of  satellites including a 

**GPM: Constellation of  satellites including a **
** ****multi-channel polarized passive microwave**
** ****radiometer  and a radar system for**
** ****measuring rainfall.**

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## HOW WOULD NASA’S OBSERVATIONS BE USED?

**Improve understanding of current hydrologic cycle and processes**
**Improve climate models**
**Assess progress in prediction by comparing models and observed trends**

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## BUT NOT ONLY NASA...

**NEED A GROUND BASED NETWORK (INTERNATIONAL COOPERATION)**
**REMOTE SENSING PROVIDES AREA-AVERAGING TO LOCAL OBSERVATIONS**
**VALIDATES REMOTE SENSING RETRIEVALS**
**OTHER U.S. AGENCIES**
**USGS**
**NOAA**
**ON-GOING PROGRAMS**
**GEWEX**
**WCP-WATER**

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## Slide 20

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## WHAT ARE THE CHIEF NEEDS?

- OBSERVATIONS
- Integrated soil moisture to rooting depth - the holy grail
- Long-term monitoring
- MODELS
- Accurate depiction of future temperature gradients - governs precipitation

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**Model estimates of potential water storage must be evaluated. **

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## PRACTICAL BENEFITS

**Understanding of current water cycle**
**Improved water management**
**Better understanding of geopolitical implications of climate change**
**Better assessment of cost/benefit ratios for policy options**

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## LONG TERM CLIMATE RESEARCH IS SYNERGISTIC WITH OTHER NASA VISION QUEST TOPICS

**SEA LEVEL RISE**
**HURRICANES**
**BIODIVERSITY**
**SUBSEASONAL WEATHER PREDICTORS**

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## WATER RESOURCES ARE ALREADY AT RISK AS POPULATION GROWS

**Population growth**** will stress ****water resources**** in already vulnerable  regions.**
**Population pressures**** are already causing ****water problems**** in countries such as Algeria, Kenya, Rwanda, Tunisia and many in the Middle East.**
**Future ****population growth**** will likely cause ****water problems**** in additional countries such as Egypt, South Africa, Iran, Somalia and Ethiopia, among others.**
**Population growth**** is causing ****water problems**** in the Southwest and some Western States in the U.S.**
**These problems will likely be exacerbated by ****climate changes****.**

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## WATER RESOURCE STRESSES ARE ALREADY CAUSING CONFLICTS 

**A long history of conflicts and disputes exists over shared ****water resources**** (e.g., Middle East).**
**Environmental refugees are created by droughts**** ****in Africa and Asia.**
**Friction among states in the Western U.S. is growing due to inefficient use and growing competition for ****limited resources****. **
**Friction among farmers, cities, and the environment is growing in many regions.**
**Water allocation ****disagreements even affect states in the Northeast (N.Y., Pa., N.J.).**

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## CLIMATE CHANGE WILL FURTHER ALTER WATER AVAILABILITY

**Current short-term**** climate perturbations**** (e.g., ENSO events) alter ****water availability**
**Climate changes**** have altered ****water availability ****in North America in the past**
**Climate warming**** will affect ****water availability**** as evaporation increases and rainfall is altered.**
**Intensification of the ****hydrologic cycle**** should result in more floods and droughts.**

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## HOW WILL WATER RESOURCE CHANGES IMPACT SOCIETY?

**Water resources**** are closely related to energy cost and consumption - and energy, in turn, is reciprocally related to ****global warming**** and population growth.**
**With ****drought**** in 1988, power plants in the Northern U.S. were shut down entirely due to lack of ****water**** for removing heat.**
**Heavier rainfall events (which are already happening in the United States) will increase the risk of flooding in river basins (where ****population**** is growing).**
**Warmer climate**** and ****water stress**** will mean an increased health risk in an ****aging population****.**
**Agricultural production will be altered, with vulnerable (Third World) countries particularly affected.**

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## OUR ABILITY TO OBSERVE AND PREDICT FUTURE RISKS IS CURRENTLY INADEQUATE

**Our ability to observe global ****hydrologic components ****on a local level needs substantial improvement.**
**Our ability to predict areas at risk associated with ****climate change**** is, in general, poor.**
**Some regional impacts are more certain than others, such as reduction in snowfall**** ****at mid-latitudes, and likely increases in rainfall at high latitudes.**
**Climate models differ in their forecasts of regional ****water availability**** changes.**
**Impact models and climate models produce inconsistent results.**

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## NASA HAS AN IMPORTANT ROLE TO PLAY BY PROVIDING GLOBAL OBSERVATIONSTHIS IS NECESSARY BECAUSE:

**The ****hydrologic cycle**** is  globally connected (e.g., El Nino affects the U.S. rainfall).**
**Climate change**** impacts are global and will affect the U.S. economy.**
**Water resource ****changes are a potential source of global ****geopolitical**** instabilities. **
**Remote sensing is needed to provide global ****hydrologic****  observations.**

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## HOW WILL NASA’S OBSERVATIONS BE USED?

**To provide better knowledge of the current ****hydrologic state**** and its variability, as well as help in understanding the processes.**
**The Global Precipitation Mission (GPM) and the Gravity Recovery and Climate Experiment (GRACE) will contribute to this effort.**
**To improve climate models so as to help in predictions of future ****water availability**** being made with NASA’s GCM and other models.**
**To continually assess progress in prediction capability through comparison of forecast and observed trends. **

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## WHAT DO WE NEED TO DO?I.OBSERVATIONS

**Explicitly involve water managers in the process. **
**While some obvious measurements are already being planned (e.g., precipitation), preparatory work to define future observations includes:**
**Utilize already completed field experiments in an integrated fashion to better understand processes.**
**Establish a Supersite where observations to assess the sensitivity of needed observations and to define the required processes on the relevant scales  (watershed, ecosystem, and field) can be made.**
**Define the quantifiable criteria (e.g., precipitation, streamflow) that can be used to assess climate model hydrologic performance and improvements.**
**By 2010 be in a position to prioritize measurements and scale-sizes for both ground-based and remote sensors.**
**Establish the surface network and remote sensing capability to measure these quantifiable criteria, if not already available.**
**Continue the necessary measurements for the long-term.**

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## WHAT DO WE NEED TO DO?II. MODELS

**Improve the prediction of climate variables that affect precipitation and evaporation (e.g., sea surface and local temperatures, planetary waves). **
**Improve land surface models:**
**Define the relevant physiognomic units and properties on the various scales that must be included to make models more realistic.**
**Prepare global data bases of these relevant land characteristics.**
**Include human influence on the land surface in models.**
**Improve computer power to allow for finer-scale regional assessments.**
**Perform sensitivity analyses to quantify needed observations.**
**Make continual comparisons between the model results and observations for the quantifiable criteria for mean conditions, interannual variability, and trends.**

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## THIS RESEARCH WILL PRODUCE PRACTICAL BENEFITS, SUCH AS:

**Improved understanding of the current hydrologic cycle and water availability, at all scales.**
**Improved water management, including long-term planning (e.g.reservoir storage, water transfer or treatment facilities), and floodplain development.**
**Better understanding of the ****geopolitical implications**** of changes in ****water availability. **
**More accurate assessments of the economic costs and benefits of policy options.**

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## LONG TERM CLIMATE RESEARCH IS SYNERGISTIC WITH OTHER NASA VISION QUEST TOPICS

**Sea level rise will affect ****water quality ****and ecosystem health.**
**Improved understanding of tropical storm processes will help in forecasting how hurricane frequency and intensity will change in the future, affecting ****water availability**** along the U.S. east coast. **
**Better understanding of sub-seasonal weather predictors that affect ****water availability**** today, will allow for better forecasts of their future effects. **
**Water availability**** changes will have important consequences for ecosystems and biodiversity.**

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