Some facts about CO2
CO2 is a colourless and odourless gas. We are not witnessing CO2 emissions when we see smoke coming from factory chimneys and automobile exhaust pipes – that smoke is caused by other gases or water vapour. CO2 does not pollute locally.
Being or living close to an emission source is not detrimental to your health. The problem, however, is that increasing CO2 emissions are raising the atmospheric CO2 levels, which in turn is intensifying the greenhouse effect. The effect on global warming is not dependent on where carbon dioxide is emitted. What counts is the total amount of global CO2 emissions.
CO2 is not toxic, unless you are locked inside a room full of CO2, which can lead to suffocation by the displacement of breathable oxygen. CO2 is added to soft drinks to make the bubbles (‘carbonated drinks’). In its solid state, CO2 is called dry ice, which is widely used to cool food, drinks, etc. CO2 is also used in greenhouses and fire extinguishers. Currently, the use of CO2 for heating and air-cooling of cars is being tested.
At normal temperatur es and pressure, CO2 is a gas. Under normal atmospheric pressure, it goes directly from gas to solid (‘dry ice’) at −78.5 °C. Liquid carbon dioxide forms only at pressures above 5.1 atm. CO2 gas is heavier than air, but when discharged in air it mixes thoroughly with air within a relatively short time.