Truth is preferable to falsehood, for sure. But it can be damn depressing at times. That's how I felt today while listening to a Salem City Club talk about climate change from an Oregon perspective.
The speaker was Erica Fleishmann, Professor, College of Earth, Ocean, and Atmospheric Sciences, who is the Director of the Climate Change Research Institute (CCRI), a network of researchers and professionals that is housed at Oregon State University in Fleishmann's college.
One of CCRI's missions is to research and monitor the state and regional climate. Every two years CCRI publishes an updated Oregon Climate Assessment. The 2025 assessment can be downloaded via the CCRI web site. There's a two-page Executive Summary. This is the not-so-cheery section on Temperature and Precipitation.
Temperature and precipitation. Oregon’s annual average temperature increased by 2.2°F per century since 1895. Without considerable reductions in greenhouse gas emissions, annual temperature in Oregon is projected to increase by at least 5°F by 2074 and 7.6°F by 2100, with the greatest seasonal increases in summer. Precipitation is projected to increase during winter and decrease during summer, and the intensity of heavy winter precipitation events is projected to increase. Furthermore, the proportion of precipitation falling as rain rather than snow is expected to increase. Increases in extreme temperatures contributed to recent revisions of the national Plant Hardiness Zone Map.
This is the section on Drought.
During 18 of the years from 1999–2023, Oregon’s precipitation was below average. The average temperature was warmer than normal in 21 of those years, which contributed to higher rates of evapotranspiration and more-frequent drought. Drought risk likely will increase over the twenty-
first century on the western slopes of the Cascade Range and the southern Coast Range, decrease in the Deschutes and John Day basins in north-central Oregon, and change little elsewhere. Drought risk during summer is likely to increase statewide.
Fleishmann showed some slides that echo the most recent Oregon Climate Assessment.
The red bars on the chart above indicate periods between 1950 and the present when the annual average temperature in Oregon was greater than the 1950-2014 baseline. It's clear that the early part of this period had mostly blue bars, meaning a temperature less than the baseline, while more recent years have been largely above the baseline.
From here on out, the orange'y shadings show various warming scenarios, with the most likely being an 8 degree increase over the baseline by 2100 in the annual average temperature .
You can see that from 1990 to 2020, Salem averaged 15 days a year with a heat index of 90 degrees or above. The index is a blend of temperature and humidity, but since our summers usually aren't humid, Fleishmann said that the heat index basically is based on temperature.
The projected extreme heat index for 2070-2099, when, thankfully, I'll be dead and gone, shows that Salem is expected to have 53 days a year of 90 degrees or above, over three times what we have now.
Regarding precipitation, there isn't as clear a trend as there is with temperature. There have been more drier than normal years since 2000 compared to wetter than normal years. The long term trend is very uncertain, as shown by the large width of the right side of the slide. By 2100 the most likely scenario is a fairly small increase in annual precipitation, around 7-8 percent.
However, some areas are expected to get an increase in extreme precipitation.
More precipitation is expected to fall as rain rather than snow in those mountainous regions.
Another slide showed how the causes of wildfires differ in various parts of Oregon. Most wildfires on the west side of the Cascades are caused by humans, while most wildfires on the east side of the Cascades are caused by lightning.
In the Q&A part of the program, Fleishmann said that carbon capture is still in the research and development stage so won't be able to quickly reduce greenhouse gases; that while Oregon is warming, we're better off than some other areas, like Arizona, so may see some climate-caused migration to our state; that while climate change initiatives are being rolled back at the national level, we will continue to stand with like-minded states; that frequent wildfire smoke inhalation has some negative long-term health effects, including premature birth.
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