Final answer:
Two environmental factors that affect the spread of a viral pathogen are temperature and moisture, which can create conducive conditions for transmission, and human behavior, particularly urbanization and travel, which can facilitate rapid viral spread.
Step-by-step explanation:
Two environmental factors that affect the spread of a viral pathogen include temperature and moisture. High temperature and moisture levels can provide optimal conditions for the transmission of certain viruses, such as those causing the common cold or influenza. Conversely, extreme cold or dry conditions may limit the spread of these pathogens.
Another key factor is human behavior related to urbanization and globalization. Urban areas with high population density can facilitate the rapid spread of viruses through direct contact, such as touching contaminated surfaces or skin-to-skin contact. Global travel enables pathogens to move quickly across large distances, potentially causing outbreaks to become pandemics if not contained early.