The Gulf Stream plays a significant role in maintaining the climate of the US East Coast and Western Europe. “We conclude with a high degree of confidence that Gulf Stream transport has indeed slowed by about 4% in the past 40 years.” The full study is Here
East coast of Canada and US will become arid. Caribbean will become hotter and storms will become more severe. Scotland, Ireland, Iceland, and Norway will be substantially colder (compare latitude of UK with Northern Canada) and with less precipitation. Basically, everywhere that relies on warm tropical moist air currents will drastically change.