List ways to reduce the concentration of carbon dioxide in the atmosphere.

Reducing vehicle emissions. One of the largest CO2 producers that saturates our atmosphere are the cars that many of us use every day.
Reduced energy consumption. The only aspect of our current society that produces more CO2 emissions than transportation is electricity generation.
Reducing waste consumption. If we can recycle many of our products, less energy will be needed. Be sure to always recycle anything you can with paper and plastic.
Restoration of natural effluents. The oceans play a vital role in absorbing carbon dioxide present in the atmosphere.