What is the main cause of the greenhouse effect?1 markVolcanic activityDeforestation Industrial emissions Solar radiation

The main cause of the greenhouse effect is Industrial emissions.

Explanation

1. Volcanic Activity: While volcanic eruptions can release greenhouse gases, their contribution to the greenhouse effect is relatively minor compared to human activities.

2. Deforestation: This contributes to the greenhouse effect by reducing the number of trees that can absorb CO2, but it is still not the primary cause.

3. Industrial Emissions: These are significant sources of greenhouse gases like carbon dioxide (CO2) and methane (CH4) due to the burning of fossil fuels, chemical production, and other industrial processes. This makes industrial emissions the leading cause of the greenhouse effect.

4. Solar Radiation: Although it is the source of energy for the Earth, it does not cause the greenhouse effect; rather, it is the trapped heat from solar radiation that leads to the greenhouse effect.

In conclusion, the correct answer is Industrial emissions, as they are the predominant contributor to the enhanced greenhouse effect observed in modern times.