By Daniel W. Nebert

Summer solstice is that time of year when our sun is “closest to directly overhead”; the next day it begins its gradual march toward winter solstice, when the angle of the sun is most oblique (for us in the Northern Hemisphere). Between June 14 and 28, Portland sees 17 hours from sunrise to sunset, give or take a minute or two. This all has to do with the tilt of Earth, combined with its orbital movement around the sun.

During the summer solstice 2021, Portland saw consecutive high-temperatures of 108^oF, 112^oF, and 116^oF; this became known as the “2021 Western North America Great Heat Wave.” Of course, the news media (and even Wikipedia) declared this freak weather event as a harbinger of the coming “gloom-and-doom end, of the world as we know it” — due to “human-caused climate change.” [However, “climate” is measured in decades and centuries; “weather events” are measured in days, weeks and months.]

During this first week of summer solstice 2023 (June 15 and 20), Portland has had highs between 55^oF and 77^oF — i.e., 39^oF to 61^oF cooler than our record 116^oF two years ago! Earth’s “five most important naturally-occurring greenhouse gases” include carbon dioxide (CO₂), ozone (O₃), nitrous oxide (N₂O), methane (CH₄), and water vapor (H₂O). Which one might be the most critical in causing differences in our surface temperatures between summer solstice 2021 and 2023?

To read the newspapers, watch television, or attend Oregon’s schools, our indoctrinated citizens would promptly vote for “the evil CO₂.” But — is it fair to blame “industrial pollution’s CO₂” as the cause of the 2021 Western North America Great Heat Wave? Between June 2021 and June 2023, what differences can we see among the five most important greenhouse gases? There has been far less than one percent change in CO₂, O₃, N₂O and CH₄.

So, what is different between these two years? If you answered “clouds,” go to the head of your class! The Jet Stream is the immediate cause of the differences between these two weather events.

In 2021 there was a massive “heat dome” centered over the northeastern Pacific Ocean; this diverted the Jet Stream far to the north. In summer solstice 2023, the Jet Stream is displaced further to the east, causing substantial cloud cover with an intermittent barrage of thunderstorms, hail, and on-and-off showers in the Pacific Northwest.

Therefore, instead of hysterical terms such as “decarbonization,” “carbon footprint,” “carbon-neutral companies” and “carbon net-zero plans,” might we suggest (tongue-in-cheek) that climate alarmists change their nonsense terms to “dewaterization,” “water footprint,” “water-neutral companies” and “water net-zero plans”? In summary, H₂O vapor elicits hundreds of times greater effect on our daily weather than the other four greenhouse gases, combined!

Daniel W. Nebert is professor emeritus in the Departments of Environmental and Public Health Sciences, University of Cincinnati College of Medicine; and Pediatrics and Molecular & Developmental Biology at Cincinnati Children’s Hospital. He now lives in Oregon.

This commentary was first published at The Northwest Connection, June 21, 2023, and can be accessed here.