Randall Dole
NOAA Earth System Research Laboratory
MTNCLIM 2006 Workshop
September 21, 2006
1

The Climate Change Science Program (CCSP) plans and coordinates
U.S. research efforts in the areas of climate and global change.
Activities involve 13 federal agencies.
• Reduce uncertainties in climate science.
• Improve global observing systems.
• Develop science-based information to support policymaking and resource management .
• Communicate findings to science and user communities.
One CCSP Near-term Priority:
Integrating Observations and Models to
Improve Decision Support.
Will illustrate with an issue of fundamental importance to the West: Drought.
2

Droughts are more than simply climate phenomena. They have profound social, environmental, and economic impacts.
North Platte river
May 22, 2002
Mean flow - 1310 cfs
Observed - 0
… the last rains came gently, and they did not cut the scarred earth … the sky grew pale and the clouds that had hung in high puffs for so long in the spring were dissipated.
John Steinbeck, Grapes of Wrath.
3

“ “ Whiskey is for Drinking and Water is for Fighting ” ” Mark Twain.
“ “ Water is life ” ” Wallace Stegner .
.
‰ There are growing concerns for the sustainability of water resources to meet future demands.
• Increasing public and media attention.
• Recognition of secondary impacts of drought.
• Concerns over how to best manage water resources and plan for the future.
4

Interior Department analysis of potential water supply crises and conflicts by the year
2025 based on a combination of technical and other factors, including population trends and potential endangered species needs for water.
Note: There is an underlying assumption of a statistically stationary climate .
5

“ Creating a National Drought Early Warning System ”
NIDIS Goal: To enable the Nation to move from a reactive to a more proactive approach to droughts.
• The Western Governors’ Association
(WGA) spearheads a report providing the vision and recommendations for developing NIDIS.
• NOAA is recommended to be the lead agency for coordinating NIDIS implementation.
• NOAA creates a NIDIS Program
Office, housed at ESRL, to coordinate NIDIS activities within
NOAA and with federal, state, and local partners.
www.westgov.org/wga/publicat/nidis.pdf
6

Observations and models show a strong relationship between western U.S. rainfall and long-term variations in ocean conditions (particularly the tropical Pacific).
Western US
Observed Rainfall
1950-2004
Forced Only by
1950 2004
7

8

Following results are courtesy of Marty Hoerling and Jon Eischeid, NOAA
ESRL.
Simulation of past climate and projection of future changes usin g
‰ Simulations of past climate for period 1895-2005
‰ Specified monthly varying GHG, aerosols, solar, volcanic forcings.
‰ Projections using A1B Scenario for 2001-2060.
‰ 18 Different Coupled Models and 42 total runs for the period 1895-2060.
‰ Experiments are part of the IPCC AR4 Suite.
Model data available from: http://www-pcmdi.llnl.gov/ipcc/about_ipcc.php
9

Observations
Simulation
Projection
2040-2060
10

Observations
Simulation
Projection
2040-2060
11

Observations
Simulation
Projection
2040-2060
12

Projected PDSI Changes for Watershed Basins
West Midwest East
13

Projected Streamflow Change at Three Gauges
West Midwest East
14

• Air temperatures are virtually certain to warm further in coming decades
• Warmer air temperatures alone would greatly increase drought severity and duration
• Warmer air temperatures would probably severely reduce the quantity of water resources
• It is unlikely that precipitation changes will compensate for surface water losses by evapotranspiration
• The semi-arid and arid West is found to be at greatest risk. It is likely that Lees Ferry flow will decline below 20th Century consumptive uses within a mere 25 years
15

• Make clear connections with CCSP strategic plan goals
• Take advantage of focusing events (Western drought)
• Emphasize key regional issues and impacts (Western water)
• Identify system relationships (drought - fire - carbon..)
• Clarify, and if possible, quantify relationships between climate variations and change and impacts (scenarios).
• Provide information on decision-relevant variables (NIDIS).
16