Melting ice reveals a Viking-era pass in Norway’s mountains
It was warmer at that time than now.<p><a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/medieval-warm-period" rel="nofollow">https://www.sciencedirect.com/topics/earth-and-planetary-sci...</a><p>The medieval warm period coincides with the viking expansion and contraction.<p>Edit: see response, below