The excerpt uses a cause-and-effect text structure to explain how climate change could affect the spread of infectious diseases. The paragraph first identifies how the warmer winter temperatures due to climate change could allow ticks and mosquitoes to survive longer and expand their ranges. This leads to the effect of more people being at risk of diseases that these insects carry, with malaria being a specific example.
The paragraph then transitions into discussing actions that individuals and communities can take to address the issue, indicating that these actions could have a positive impact on controlling the spread of diseases. Finally, the paragraph ends by stressing the importance of doctors being aware of the symptoms of such diseases so that they can diagnose and treat their patients. The use of cause-and-effect text structure in this paragraph allows the author to explain the relationship between climate change and the spread of diseases in a clear and concise manner.