carbon dioxide

noun

1. The normal oxide of carbon, CO₂; a colorless, odorless gas formed during respiration and combustion and consumed by plants during photosynthesis.

   “There were dozens of presentations in 2008, including: […”

   “Oxygen levels on Earth skyrocketed 2.4 billion years ago, when cyanobacteria evolved photosynthesis: the ability to convert water and carbon dioxide into carbohydrates and waste oxygen using solar energy.”