Changes in the strength of the Gulf Stream can have a large impact on the temperature of Europe. A strengthening of the Gulf Stream would warm Europe.

Changes in the strength of the Gulf Stream may be the result of changes in the thermohaline circulation. A change in the thermohaline circulation will caused by changes in the processes that cause deep water formation.

For example, the presence of fresh water from continental snow melt may create a stable layer on the ocean surface thus weakening the thermohaline circulation and heat transport towards Europe. This would be expected during the withdrawl of the ice ages such as during the Younger Dryas event.