For example, plants which leave dormancy (or proceed to a new phase such as flowering) during the unusually warm periods, only to be severely damaged when the c

For example, plants which leave dormancy (or proceed to a new phase such as flowering) during the unusually warm periods, only to be severely damaged when the cold returns. Species may be maladapted to the new weather patterns. We also see the less direct ecological effects such as new pests thriving in area -- new weather patterns create an ecosystem to which the species is no longer adapted. E.g. fungi killing trees. Or for humans, "tropical diseases" becoming common in more northern areas.