The substance primarily responsible for the greenhouse effect is carbon dioxide (CO₂). This gas traps heat in the Earth's atmosphere, leading to a rise in global temperatures. While natural processes contribute to CO₂ levels, human activities such as burning fossil fuels and deforestation have significantly increased its concentration. The greenhouse effect is essential for maintaining Earth's temperature; however, excessive CO₂ exacerbates climate change and disrupts climatic patterns. Understanding the greenhouse effect is vital in addressing environmental issues and developing strategies for sustainable practices to mitigate its impact on global ecosystems.