Carbon Dioxide Emission Hit A Record High

Burning fossil fuels such as coal and petroleum is the leading cause of increased anthropogenicCO₂; deforestation is the 2nd major cause.  


Irreversibility and uniqueness of carbon dioxide

Carbon dioxide has unique long-term effects on climate change that are largely "irreversible" for one thousand years after emissions stop (zero further emissions) even though carbon dioxide tends toward equilibrium with the ocean on a scale of 100 years. The greenhouse gases methane and nitrous oxide do not persist over time in the same way as carbon dioxide. Even if human carbon dioxide emissions were to completely cease, atmospheric temperatures are not expected to decrease significantly in the short term.

Source: Carbon_dioxide_in_Earth's_atmosphere