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Yes, California has had droughts lasting ~220 and ~140 years before. The findings suggest, in fact, that relatively wet periods like the 20th century have been
by simonsarris 4y ago
Yes, California has had droughts lasting ~220 and ~140 years before.
The findings suggest, in fact, that relatively wet periods like the 20th century have been the exception rather than the rule in California for at least the last 3,500 years, and that mega-droughts are likely to recur.
The South American drought was of "horrendous proportions," said Dr. Kolata, and it destroyed Tiwanaku's agricultural base. The empire's cities were abandoned by about 1000. Dr. Kolata believes that the raised fields could no longer support the cities, and archeological evidence shows that the fields were abandoned between 1000 and 1100. The political state collapsed, the population dispersed and, with agriculture no longer possible, the people relied on raising alpacas and llamas.
https://www.nytimes.com/1994/07/19/science/severe-ancient-droughts-a-warning-to-california.html https://www.nytimes.com/1994/07/19/science/severe-ancient-dr...
- kokanee 4y agoIs the implication here that we should wait another 3,500 years for our reservoirs to return to their former peak levels? I'm not sure that trends from a geological time scale are helpful in current public policy debates on natural resource shortages or climate changes.
- antognini 4y agoOne of the root causes of the dysfunction of water policy in the West is that expectations around water availability were set in the early 20th century which turned out to be historically anomalous. Long term water agreements between states and with Mexico were based on assumption that those water levels would continue. Now we are seeing reversion to the mean, but it takes a long time for water policy to be updated. There is a saying that water policy in the West is 21st century needs on top of 20th century infrastructure and 19th century law.