How useful can Carbon dioxide be to man?

A partial list is given here: Carbon dioxide - Wikipedia The utility of any compound depends on its chemical and physical properties, availability and cost. Carbon dioxide is readily available, and relatively low cost. read more

As an inert gas - CO2 is the most used compressed gas for pneumatic systems, in welding (to exclude oxygen), inflatable life jackets, airguns, as explosive (via rapid vaporization of liquid carbon dioxide), food drying, and decaffeination of coffee beans. read more

Exhaust from one cycle of electricity production could be used immediately to deliver another flow of power to the grid. By Tim Radford. Dutch scientists have thought up a new use for all the carbon dioxide that pours from the chimneys of fossil fuel-burning power stations: harvest it for even more electricity. read more

In addition, carbon dioxide is sometimes used as a gaseous blanket to prevent substances from decaying. In rare circumstances, carbon dioxide can be a threat to life. In 1896, a huge cloud of the gas exploded from Lake Nyos, a volcanic lake in northwestern Cameroon, a nation in western Africa. read more

Carbon dioxide is the lasing medium in a carbon dioxide laser, which is one of the earliest type of lasers. Carbon dioxide can be used as a means of controlling the pH of swimming pools, by continuously adding gas to the water, thus keeping the pH from rising. read more