Question

what impact can a volcanic eruption have on climate?
climate is warmed as dust increases the greenhouse effect.
climate is cooled as dust falls from the sky.
climate is cooled as dust blocks incoming sunlight.
climate is warmed from the heat of the eruption.

Explanation:

Volcanic eruptions release ash and dust into the atmosphere. These particles can block incoming sunlight. When sunlight is blocked, less solar energy reaches the Earth's surface. This leads to a cooling effect on the climate. The greenhouse - effect - related warming (due to dust) is incorrect as volcanic dust is mainly reflective. Dust falling from the sky does not directly cause cooling in the relevant sense here. The heat from the eruption is a local and short - term effect, not a major factor in long - term climate impact.

Answer:

Climate is cooled as dust blocks incoming sunlight.