October 21, 2015
California Weather Headed For Greater Precipitation Swings
The hot September 2015 weather continues a trend in the year toward making 2015 the warmest year on record. If green house gas emissions continue at current or even higher rates then California will experience greater swings between very wet and very dry weather with less moderate weather in between.
The models showed that in the future, assuming emissions continue to increase, California seasons will exhibit more excessively wet and excessively dry events. These results suggest that the frequency of droughts could double and floods could triple between the early 20th century and late 21st century.
"By 2100, we see more -- and more extreme -- events. Flooding and droughts will be more severe than they are currently," said Yoon.
What's less clear: the impact on average precipitation. But even if it stays the same on average warmer weather will cut storage of water as snow and therefore reduce availability of water in spring and summer. Plus, warmer temperatures will cause water to evaporate from soils more quickly. This all will reduce the amount of water available for agriculture unless a large amount of water released in deluge years can be captured and stored.
The El Nino Southern Oscillation (ENSO) will cause the more severe swings in precipitation in California.
Without El Nino and La Nina, the frequency of extreme precipitation in California stayed constant for the simulation's century and a half. With ENSO, simulated California experienced wide swings in rainfall by the end of the period.
On the bright side, advances in technologies useful for climate engineering could help. I can even conceive of robots employed to do massive tree planting in order to suck CO2 out of the atmosphere.
Randall Parker, 2015 October 21 07:32 PM
The satellites, which actually measure temperatures over the whole earth, not merely urban airports, show essentially no increase in mean temperatures for the last 19 years or so. 1998 is the warmest year in that record because of the unusually strong El Nino. We're about to enjoy another one.
The surface records produced by NASA are widely thought to be fabrications. The raw data show little trend over the 20th Century; all the warming comes from adjustments made to the raw data. That itself is suspitious. But in addition, most rural weather stations were shut down in the 90's for cost cutting. Also, airport stations, which is essentially all that remains, are increasingly influenced by the urban heat island effect. Some airports like the one at Columbus, Ohio, have gone from being in the very rural outskirts of a small city to being in the middle of a large conurbation. Surely, one would think, the modern temperatures reported there should be corrected downwards.
Historically, world temperatures have been sliding down for the last 10,000 years or so because of orbital mechanics. Excursions like the Minoan Climate Optimum, the Roman Climate Optimum, the Medieval Climate Optimum and the current Optimum are likely due to variations in solar output. Go look at the Vostok ice cores: temperature leads carbon dioxide by 400 to 800 years. If the official estimates of carbon dioxide over the last 200 years are correct, temperature has led carbon dioxide during the recent warming, also.
By the way, they are called climate optima because a warmer Earth is better for humans and other life.
"The models showed" indicates that the author needs to take or retake basic logic and proof within science. A computer model enables more intricate computations with more elements than would be possible with paper and pen, but is still subject to the basic principle of "Garbage In, Garbage Out." The model provides predictions not proof and must be compared to reality just like any other theory's prediction.
Here's my pitch for a great movie:
The vast majority of earth's scientists cook up a scheme to convince everyone of a lie that the earth is warming due to human action. Because they're all secret communists.
Only a small group of plucky billionaires, with minor help from the world's oil companies, can stop them...
Yes, I stole that, I wish I could remember from where.