This is what I think explains varying temperatures over a 100 year+, long time span.Sibelius Hindemith wrote: ↑Tue Jul 13, 2021 6:00 amThe tilt and wobble of the axis are two causes of large-scale climate trends such as ice ages, along with orbital variations due to the pull of Jupiter which are on a 96k year cycle.gil wrote: ↑Mon Jul 12, 2021 1:20 pmInteresting stuff. But does it explain increased temperature on a world-wide scale? Change in the axis of rotation would seem to make some places warmer and others cooler (not an overall increase in temperature).Sibelius Hindemith wrote: ↑Sun Jul 11, 2021 5:10 pmThe Earth's axis of rotation wobbles.
One wobble involves the axis (relative to space)on a 26,000 year cycle where it moves along an angular radius of 23.4 degrees..
https://en.m.wikipedia.org/wiki/Axial_precession
There are also changes in the location of the axis relative to fixed points on Earth's surface which have periods of one year and 433 days..
https://en.m.wikipedia.org/wiki/Chandler_wobble
There are other smaller deviations in the axis described here..
https://www.jpl.nasa.gov/news/nasa-stud ... ling-earth
That is just the current arrangement. The Earth's orbit varies from near-circular to elliptical over a cycle with a long time span of tens of thousands of years. I'm not sure if the figures you quoted are nearer to the circular extreme or the elliptical extreme of this cycle.gil wrote: ↑Mon Jul 12, 2021 1:20 pmAs to distance from the sun:Obviously this would suggest that the average temperature in January is warmer than in July.At different times of the year, the Earth either moves closer or farther away from the Sun. At perihelion, the Earth’s closest distance to the Sun, the distance between the Sun and the Earth is 91.4 million miles. The Earth is closest to the Sun in early January. At aphelion, when the Earth is furthest to the Sun, the distance between them is about 94.5 million miles. The Earth is furthest from the Sun in early July. https://www.worldatlas.com/articles/how ... e-sun.html
Yes, there is a correlation between atmospheric CO2 levels and average global temperature but it isn't clear with regard to causality. For instance, when oceans are shallower due to more land ice they lock up more CO2 and when they are deeper due to melting ice they circulate more and release CO2. Also, other gases like methane seem to have a greater impact. I agree though that continuing to pump carbon dioxide into the air at this rate is unwise if not dangerous for the long term, but the only practical alternative to burning fossil fuels currently is nuclear power.gil wrote: ↑Mon Jul 12, 2021 1:20 pmAgain, I understand that these phenomena exist and I understand that there is natural variation and things must be looked at over time. One heat wave or one rainy month do not prove anything. But there is pretty strong evidence of increased temperatures, and I don't know of an explanation that is better than increased carbon dioxide concentration.
Similar to how the moon is closer at times, there are times we're relatively closer to or further from the sun. Maybe in 1900 we were 94.5 million miles away and now we're 94.4 million miles away on the 10,000 year cycle (or whatever it is).