Shooting or hanging..
Both are equally bad and proportional to how large the changes are. We had a "mini" ice age in medevial times, and that was bad enough. If the change is large enough..

There is a small study on the "mini" ice age here: http://www2.sunysuffolk.edu/mandias/lia/little_ice_age.html

It dont matter if it heats up or cools down, both are equally bad in my opinion.