Final answer:
A climatologist would be most surprised by snow in Phoenix in July due to their expertise in climate patterns and the awareness that Phoenix's desert climate and current trends in climate change make such an event extremely unusual.
Step-by-step explanation:
If it were to snow in Phoenix in July, a climatologist would be most surprised. This type of Earth scientist specializes in the study of climate patterns over time, and snow in Phoenix during July is highly unusual due to the region's hot desert climate. Climatologists consider factors such as regional climate patterns, historical weather data, and ongoing trends in global climate change which currently indicate increasing temperatures, particularly in areas such as Phoenix. Therefore, an event like snowfall in July would be an extraordinary deviation from their established knowledge and predictions.