Which of these human activities has directly contributed to global warming?

Question

Quizplus · Accepted Answer

Burning of coal releases greenhouse gases, primarily carbon dioxide, into the atmosphere which is a major contributor to global warming. Building of greenhouses and development of solar energy may have indirect effects on global warming, but they are not the primary culprits. Planting of trees may help to reduce global warming by absorbing carbon dioxide, but human activities are still the major contributor.

Which of These Human Activities Has Directly Contributed to Global