Carbon dioxide levels in the atmosphere have been rising

Why?Carbon dioxide levels in the atmosphere have been rising since the 19th century,when fossil fuel use increased.We know that from studying air bubbles trapped in Antarctic ice.This surge in carbon dioxide also coincides with a global temperature increase of nearly one degree Celsius.Ice cores and atmospheric monitoring stations show us that carbon dioxide levels are rising faster,and to higher levels,than at any point in the last 800,000 years.