Bob marray

I read this book about the construction of China's railway line to Tibet. "Methods included using pipes called thermosiphons along the sides of the tracks to refrigerate vulnerable parts of the soil along the highest parts of the plateau, an area that comprises the largest continuous sub-Arctic permafrost region on the planet. These cooling sticks are 7.6-meter-long steel tubes drilled into the soil; they contain ammonia, which draws latent heat out of the soil as it evaporates. " Might this be an alternative to that hole/trench? It has no moving parts.

I think the point about greenhouses overheating is a good one.

And I think the point about attempting to mitigate that based on human discipline is an even better point.

With the exception of railroad ties and telephone poles, most treated lumber doesn't used creosote anymore, thankfully. It's still something to be wary of when using reclaimed wood though.