For a complete conference summary by Mountain Counties Water Resources Association Writer Roberta Long click here.
“Climate Change–Is the time to act now? What is the risk of doing nothing?”
Panelists: Glen MacDonald, Ph.D, Botany, Michael Dettinger, Ph.D, Atmospheric Sciences, and Michael Anderson, Ph.D, Civil and Environmental Engineering.
Moderator: Mary Aileen Matheis, Director, Irvine Ranch Water District
Glen MacDonald has studied drought conditions all over the world. He lived in Tahoe City, and is familiar with Sierra Nevada conditions. As Director of the UCLA Institute of the Environment and Sustainability, he echoes the results of scientific investigations at Fall Leaf Lake.
MacDonald’s research using tree rings indicate that local dry spells can go on for more than a decade. In the 12th century, California experienced sustained low flows in the Colorado and Sacramento rivers and low rainfall for a period of 40 to 60 years. At the same time, there was a drop in volcanic activity and a spike in solar radiance, leading to natural climate warming. It affected forests and fires. We have similar conditions today, he said.
The Palmer Severity Index measures soil moisture. The map shows that as of March, the western United States, with the exception of the Pacific Northwest, and a portion of Colorado, are in various states of drought. Northern and Central California are designated moderate drought zones, southern California as severe drought, and the northeastern area as extreme drought.
MacDonald said many people believe we can cope with climate change through technology, but the past can tell us a lot about what kinds of general strategies allowed societies to survive over time. Some previous civilizations successfully managed their resources for many centuries and some did not. We may be in for a long-term drought, and there are lessons we can learn.