Final answer:
If Earth were more reflective, the global temperature would decrease due to a higher albedo leading to more sunlight being reflected away from the planet's surface.
Step-by-step explanation:
If Earth were more reflective, its temperature would go down. This is because a higher reflectivity, or albedo, means that more sunlight is reflected back into space, rather than being absorbed by the Earth's surface and atmosphere. The Earth's albedo is a crucial factor in determining the planet's climate and energy balance. A higher albedo would reduce the amount of solar energy absorbed by Earth, therefore reducing the greenhouse effect and lowering the average global temperature. For instance, if Earth's ice caps were to melt, the albedo would decrease because the ice, which is highly reflective, would be replaced by less reflective water or land. This would result in Earth absorbing more sunlight, leading to a rise in temperature. Conversely, if the Earth became more reflective, perhaps due to an increase in cloud cover or ice extent, less solar energy would be absorbed, leading to a lowering of global temperatures.