Dairy Farming in Iceland

Shellfish could supplant tree-ring climate data : Nature News: "For example, in early Norse Iceland — part of the 2,000-year era spanned by the study — farmers were dependent on dairy farming and agriculture. 'For a dairy culture, summer is by far the most important,' he says. 'A one-degree decrease in summer temperatures in Iceland results in a 15% decrease in agricultural yield. If that happens two years in a row, your family's wiped out.'"

Very interesting. Sure, climate changes but I never hear them talking about this.