Short answers, pulled from the story.
Jan Baptist van Helmont first described carbon dioxide as a discrete gas in 1640, calling it spiritus sylvestris. He observed the missing mass from burning charcoal transmuted into this invisible substance.
The concentration of carbon dioxide in the Earth's atmosphere reached 428 parts per million as of July 2025. This level represents a rise from pre-industrial levels of 280 parts per million driven primarily by the burning of fossil fuels.
Carbon dioxide deposits directly from a gas to a solid at temperatures below 194.6855 Kelvin, which equals minus 78.4645 degrees Celsius. This solid form is commonly known as dry ice and was first described by Adrien-Jean-Pierre Thilorier in 1835.
A catastrophic release of carbon dioxide from Lake Nyos in Cameroon in 1986 killed 1,700 people and thousands of livestock. The gas settled in low-lying areas and suffocated everything in its path because it is heavier than air.
The largest commercial use of carbon dioxide is in the production of urea for fertilizer, accounting for 130 million tonnes annually. Enhanced oil recovery follows as the second largest use, consuming 70 to 80 million tonnes of the gas each year.