Weather
The one thing that in my mind ties everything together is the weather. The first thing I do in the morning is to check the weather. I have a rough idea what the forecast is for the new day but I need to confirm it then plan my day. Wind is major thing to think about. high winds may shut down the windmill and if they are really gusty I lower the tower. The solar cells too are vulnerable on the roof of my barn. I could have put them at ground level but they would have missed quite a long period of sunshine in the morning on the west side of my barn. So I put them horizontal in very high winds and tie them just to make sure.
Knowing the weather is very useful. By looking at the high and low pressures I am able to predict the direction of the wind and the speed and prepare for it. I can easily see the cold and hot coming as well as rain and snow.
Those who want to live sustainably need to know the weather well.