Each thousand feet of elevation shifts climate roughly a hundred miles northward.

Evidence

Moving up the mountainside was the ecological equivalent of walking to Canada. The warm valley floor could give us a Georgia summer, while the five-thousand-foot summits are akin to Toronto. “Bring your warm jackets,” I told them. An increase of one thousand feet is equivalent to moving a hundred miles northward and therefore many steps back into spring. The dogwoods on the lower slopes were in full bloom, creamy-white sprays against the emerging leaves. Moving upslope they reversed like a time-lapse camera running backward from open blossoms to tightly bound buds not yet awakened by heat. — Robin Wall Kimmerer, Braiding Sweetgrass, 788

Categorization

• SHARE: The ‘one thousand feet equals one hundred miles north’ rule and the upslope time-lapse of blooming reversal is exactly the vivid eco-fact a landscape-reading friend would enjoy.
• CANDY: A walkable, tweetable fact: climb a thousand feet and you step a hundred miles north — with dogwoods reversing from bloom to bud like a time-lapse running backward.