The article discusses how human activities like burning fossil fuels, clearing forests, and making cement release carbon dioxide into the atmosphere. When we burn fossil fuels, carbon stored in the earth is released as CO2. Cement production and forest clearing also contribute to CO2 emissions. For example, making one ton of cement releases 0.136 tons of carbon as CO2. Burning timber releases 0.26 tons of carbon per cubic meter. These activities are adding more CO2 to the air, which can contribute to climate change.