This one stirred up many interesting and varied arguments at lunch, even spilling over to email throughout the day:
How much of the variation in earths’ temperature across the seasons is accounted for in terms of (1) the changing daylight hours (resulting in either shorter or longer exposure times) vs (2) changing altitude of the sun (resulting in more or less incident flux)? Does your answer depend on where you live? More importantly, how do you know and why do you believe?
As usual, guesses, intuition, wild speculation, careful theory, contrived experiments, and natural data are welcome.
** My bigger point in bringing this up was more to these questions: What does it mean to explain the seasons? How do we want students to approach and attempt to make sense of the seasons? **