This research report for a regional study on the impacts of climate change on the spread of pests contributes to FAO’s normative work, as a milestone for 2020–2021 under the Regular Programme. The year 2020 was designated by the United Nations as the as the International Year of Plant Health (IYPH), with the aim of reducing crop loss from pests, which is estimated at 40 percent. In the current report, agricultural pests as any organism harmful to plants, including viruses, bacteria, fungi, nematodes, insects, etc are defined by the authors. We include those that cause direct damage as well as disease-causing organisms. Climate change is projected to worsen crop losses by another 10–25 percent, which in some regions would emanate from associated pests. Central Asia, the Caucasus and Southeastern Europe are under the research area.