I’ve been going through the new report about climate change in the Puget Sound region, and I can tell you that the most optimistic chapter is the one on farming. Check out the story I wrote for the Encyclopedia of Puget Sound.
To be sure, farmers will have plenty of problems to contend with. Rising sea levels and more intense rainstorms will probably causing flooding and seawater intrusion where it has never been seen before. Some of today’s farmland could become unsuitable for agriculture, and drier summers will force much better management of limited water supplies.
But as the climate undergoes change, farmers can change with the climate, growing crops suitable for the conditions they face, said Kelly McLain, senior natural resources scientist with the Washington Department of Agriculture.
“Farmers are extremely adaptable,” Kelly told me. “I think water is going to be the limiting factor for almost all decisions.”
It’s hard to find that kind of optimism anywhere else when it comes to climate change in the Puget Sound region. The story I wrote to accompany last week’s release of the new report discusses the likelihood that landslides will increase because of more intense rainfall patterns. See “Shifting ground: Climate change may increase the risk of landslides” and the Water Ways post on Nov. 19.
My third and final story in the series, which will be published next week, talks about coming changes in habitats — and thus species — expected in Puget Sound as air temperatures increase, sea levels rise, rainstorms grow more intense and oceans undergo acidification.
I took on this writing project as part of my work for the Puget Sound Institute, which publishes the Encyclopedia of Puget Sound. PSI commissioned the climate report with funding from federal and state governments. The Climate Impacts Group at the University of Washington compiled the best scientific knowledge into a very readable report, which can be found on the encyclopedia’s website or on the website of the Climate Impacts Group.
One interesting chapter of the report, called “How is Puget Sound’s Climate Changing?” (3 mb) supports the understanding that climate change is not something we need to wait for. It’s something that scientists can measure now, although climatologists expect the changes to come faster as atmospheric carbon dioxide levels increase.
Here are a few of the changes that can be measured, along with a bit of explanation about the uncertainty:
- Average air temperatures have been increasing in the Puget Sound lowlands and are currently about 1.3 degrees higher than in 1895. Higher temperatures have been found to be statistically significant for all seasons except spring, with the overall increase shown in a range between 0.7 to 1.9 degrees F.
- Nighttime air temperatures have been rising faster than daytime temperatures. Nighttime lows have been increasing by about 1.8 degrees since 1895, while daytime highs have been increasing by about 0.8 degrees.
- The frost-free season has lengthened by about 30 days (range 18-41 days) since 1920.
- As in other areas, short-term trends can differ substantially from long-term trends. Cooling observed from 2000-2011, for example, has not altered the long-term temperature increase.
- An ongoing debate questions how much, if any, of the long-term warming trend is a result of natural climate variability. One study says up to 80 percent may be natural, caused by atmospheric circulation, not by greenhouse gas buildup. Other researchers have been unable to replicate the findings for other data sets.
- Total annual precipitation does not appear to be increasing or decreasing over a long time scale. Spring precipitation has increased at a statistically valid 27 percent for the months March through May.
- Most studies are finding modest increases in the frequency and intensity of heavy precipitation compared to historical levels, but results depend on the time period and methods of analysis.
- Ongoing variability in weather patterns related to El Nino and the Pacific decadal oscillation will continue to strongly influence temperature and precipitation for relatively short periods. It is not clear how long-term climate change will interact with these more variable climate patterns.