Seeing (Or Not Seeing) Spots
Above is the image of the Sun's disk posted today on SpaceWeather.com. The sunspot number is 26. Here's an experiment you can do yourself: Save the image off the page to disk, bring it up in an image browser, and zoom out until it's about the size of (...a silver dollar? Nobody knows what those are anymore...) a spray can lid, or something else measuring two inches or under.
Now, how many sunspots can you see?
Imagine yourself an astronomer in 1700, using a telescope made with skills and understanding of optics available at the time, to project the Sun onto a card or a wall. How many sunspots would you see?
Be honest: Zip. Zero. None.
This is the problem we have comparing solar activity today with solar activity 200 or 250 years ago: People then did not have the instruments we have today, so the counts really don't compare. Some efforts have been made to address this, but it's really an unsolvable problem if we want accurate comparisons of sunspots in 1700 to sunspots today.
My point, which is hardly original with me, is that we see and count spots today that could not have been seen in 1700. So we may already be sliding into a Maunder-class solar minimum. If solar cycle 25 (roughly 2019-2030) is as weak as they're predicting, it may exhibit few if any sunspots that astronomers in 1700 would have seen.
Nobody knows what this means. The Sun has been slowly going to sleep since its Grand Maximum in 1958 during cycle 19. I'm not going to claim that solar activity is the sole governor of climate, but it's a major contributor. (And yes, you hotheads, I freely admit that CO2 does contribute to global warming. We're still arguing about how much. Remember that you may not use the word "denier" in my comments.) My point is that most of us will live long enough to see whether sunspot counts are in any way a proxy for global temperature.
My blood oxygen issue is the major reason we're moving to Phoenix. It's by no means the only one.