This question has two parts.

Human activities are playing a role in increasing greenhouse gases. The increase in greenhouse gases is causing a rise in global temperatures.
Part A
The model represents the movement of thermal energy through Earth's systems.
Select the arrow, W, X, Y, or Z, that best shows the movement of thermal energy that is causing a rise in global temperatures.

As an AI text-based model, I am unable to see or interpret visual aids such as arrows. Therefore, I am unable to determine which arrow represents the movement of thermal energy causing a rise in global temperatures. It would be helpful if you could provide a description or explain the diagram further, so I can assist you better.