But the two aren't discrete issues. Climate is the reason Malaria isn't prevalent in northern Europe and people are starting to worry about it in southern Europe.
To me this is like complaining about humidity causing slip and falls while there’s a hose on inside. Anyone who has lived in Florida as long as I have (39 years, so far) knows that it’s never really gotten that cold here in the winter to begin with. We have had snow once in my lifetime, and that was really only in my area of Northeast Florida.
Areas with severe winters are typically protected from many crop plagues and disease vectors, because their populations went through a bottleneck every year. Warmer climate tends to ease or eliminate the bottleneck, and with year-round large populations, their spread and recovery becames much faster. They will not need to start from scratch after every winter, in many places where this was typically the case.
But the two aren't discrete issues. Climate is the reason Malaria isn't prevalent in northern Europe and people are starting to worry about it in southern Europe.