Background Information: Pests and Disease

The increased prevalence of pests and diseases is a second-order, or indirect, climate hazard. This means that the changing climate does not cause more insects, fungi, or other disease vectors, but that the conditions brought about by climate change are more favorable for these pests. For example, some tree species in our region are in decline because they are stressed due to drought, increased temperatures, and other changing weather conditions. Trees that are stressed are more vulnerable to insects, fungus, and other disease. Additionally, pests that were traditionally limited or kept in check by colder winters are moving into our region as winters warm. Trees and plants are not the only organisms at risk – pathogens that impact humans and animals, such as ticks and mosquitos, will also spread.