Carbon is the main culprit of global warming.

CO2 is a greenhouse gas, which absorbs and radiates heat. Surfaces of Earth's land and oceans radiate thermal infrared energy (heat) when they are heated by sunlight. In contrast to oxygen and nitrogen (which make up most of our atmosphere), greenhouse gases absorb heat and release it gradually over time, much like bricks in a fireplace that gradually cool after a fire is extinguished. The annual average temperature on Earth would be below freezing if not for this natural greenhouse effect. As a result, increases in greenhouse gases have tipped Earth's energy balance disproportional, trapping more heat and causing Earth's average temperature to rise.