Which of the following contributes to the greenhouse effect?

The greenhouse effect is primarily driven by the accumulation of greenhouse gases in the atmosphere, which trap heat and lead to an increase in global temperatures. Among the options provided, carbon dioxide emissions are one of the most significant contributors to the greenhouse effect.

Carbon dioxide is released from various sources, including fossil fuel combustion, deforestation, and industrial processes. Its greenhouse gas properties allow it to absorb infrared radiation, contributing to the warming of the Earth's surface. As levels of carbon dioxide rise due to human activities, the intensity of the greenhouse effect increases, leading to climate change and its associated impacts.

While ozone depletion is a significant environmental issue, it operates differently than the greenhouse effect—primarily affecting the stratospheric ozone layer rather than directly influencing the warming of the surface. Deforestation does contribute indirectly by reducing the number of trees that can absorb carbon dioxide, but it is the increase in carbon dioxide itself that is a direct and primary cause of the greenhouse effect. Thus, carbon dioxide emissions are the most straightforward answer regarding contributions to the greenhouse effect.