It's even worse than the article suggests. Roman times as well were as warm or warmer than recent temperatures. These warmer periods were not characterized by catastrophic weather conditions but by longer growing seasons and increased agricultural production. See: Esper et al (2012, 2014)
Small time frame in the bigger picture... Solar insolation started to decrease about 8,000 years ago, we are just now catching up to the residuals of the thermal mass heat. In the longer time frame we are about to go back to “normal”. “Normal” is 80% Glacial to 20% interglacial...