What is the primary greenhouse gas emitted by human activities?

The primary greenhouse gas emitted by human activities is carbon dioxide (CO2). This gas results mainly from the burning of fossil fuels such as coal, oil, and natural gas for energy and transportation. Deforestation also contributes significantly to CO2 emissions, as trees that absorb CO2 are removed, and the carbon stored in trees is released back into the atmosphere when they are cut down or burned.

CO2 is particularly effective at trapping heat in the atmosphere, making it a critical factor in global warming and climate change. It represents the largest share of greenhouse gas emissions from human activities, which is why it is often the focus of climate change discussions and policies aimed at reducing emissions. Other greenhouse gases, while significant, are produced in smaller quantities compared to CO2. For instance, methane and nitrous oxide, while potent greenhouse gases, have a lesser overall contribution to total annual emissions when compared to carbon dioxide.