Actual title is "America colonisation 'cooled Earth's climate'," which is a better summary of TFA.
I thought the Little Ice Age actually began several centuries before this. Maybe they lengthened it, or deepened it. But something else was happening as well. Perhaps it was part of an going process... the plague in Europe and the near east etc.
link to paper: "Earth system impacts of the European arrival and Great Dying in the Americas after 1492"