What could cause an Ice age?
Surprisingly, global warming could cause an ice age. The melting of the Iceland and Greenland ice caps which would put enough fresh water into the north Atlantic ocean to shut down the global Thermohaline current that moves heat from the tropics to the northern and southern sub-artic and sub-antarctic regions. Without that heat, England would freeze. Summer would disappear from Norway and Sweden. Greenland, Iceland, and Canada would be in year-round winter. The snow would no longer melt in the summer and glaciers would start to form. .