[thaumasiotes]

This isn't as clear-cut as you might like if you're interpreting it as climate evidence. Warm-weather crops were grown in cold areas in the past by setting up artificial environments such as walls built close to the plants to absorb sunlight and radiate heat. We have many ways of modifying the climate to suit our needs, and even if that's not economical today (with cheap international shipping), that doesn't mean it wasn't economical in the past.