Russ Steele
The Department of Interor, Bureau of Reclamation has released a report on the inpact of climate change risks on and how these risks could impact water operations, hydropower, flood control, and fish and wildlife in the western United States. This report to Congress represents the first consistent and coordinated assessment of risks to future water supplies across eight major Reclamation river basins, including the Colorado, Rio Grande, Klamath, Missouri, Sacramento-San Joaquin and Truckee river basins.
For now lets just focus on the Sacramento and San Joaquin River Basins, examine how they arrived at the figures below.
According to the report the Sacramento-San Joaqun basins will face the following:
• Temperature is projected to increase by roughly 5-6 °F during the 21st century, with precipitation slightly increasing in the northern Central Valley and slightly decreasing in the southern Central Valley. The projections also suggest annual precipitation in the Sacramento and San Joaquin River Basins will remain quite variable over the next century with a slight increase of 0.6% over the Sacramento River Basin and a decrease of from 4.2 to 5.3% over the San Joaquin River Basin by 2050.
• The basin's annual runoff is projected to increase very slightly during the first half of the 21st century and slightly decline in the latter half of the century.
• Mean annual runoff is projected to increase as much as 2.5% in the Sacramento River Basin and decrease by 8.7% in the San Joaquin River Basin by 2050.
• Moisture falling as rain instead of snow at lower elevations will increase wintertime runoff and decrease summertime runoff.
Future Impacts for Water and Environmental Resources
These historical and projected climate changes have potential impacts for the basin:
• Due to early snowmelt and relatively higher winter rains from warmer conditions, the system's ability to provide effective flood protection will be reduced.
• Warmer conditions might result in increased fishery stress, reduced salmon habitat, increased water demands for instream ecosystems and increased invasive species infestations.
• Climate change-related surface water decreases are likely to significantly increase future groundwater demands.
How did they arrive at these conclusions? Computer models. Crude General Circulation Models that were rescaled to reflect regional climate variation. If you start will a group of GCMs that have little or no proven projection skills and then rescale them, you end up with unproven parts of unvallidated computer models.
According to Dr Spencer, no one has yet found a way with observational data to test climate model sensitivity. This means we have no idea which of the climate models projections are more likely to come true. Climate researchers talk about probable ranges of climate sensitivity. Whatever that means!…there is no statistical probability involved with one-of-a-kind events like global warming.
If the climate sensativity of the GCMs are unknow, how can the sensitivity of down scaled GCMs to regional models be known? They cannot, and that means the information above, which is based on models, is nothing more than a wild ass guess. But, Interior want goverment agencies to make policy decisions based on those wild ass guesses. Are you up for that?
From the historical data in the southern Sierra, Dr John Christy found no significant trend in the snow pack from 1916 to 2009. Here is a temperature plot for California, no significant trend over 80 years.
Here is a plot of percipitation from 1895 to 2008 and there is not dowward or upward trend in the data.
It is time the folk at Interior put their play models away and do a real data reality check.
