Neither H2O (water) nor CO2 (carbon dioxide) are pollutants.

CO2, carbon dioxide:

• Is essential for all life on earth;
• Is just 0.04% of earth’s air – four one hundredths of a per cent;
• Is scientifically classified as a trace gas because there is so little of it
• Is non-toxic; not noxious;
• Is highly beneficial to, and essential for, plants;
• Is colourless, odourless, tasteless;
• Natural – nature produces 97 per cent of the carbon dioxide produced annually on Earth;
• Does not discolour the air;
• Does not impair the quality of water or soil;
• Does not create light, heat, noise or radioactivity;
• Does not distort our senses.
• Does not degrade the environment nor impair its usefulness nor render it offensive;
• Does not make land water or air dirty or unsafe to use;
• Does not cause disease;
• Does not harm ecosystems and is essential for ecosystems;
• Does not harm plants &animals. Essential for plants and animals;
• Does not cause discomfort, instability or disorder;
• Does not accumulate;
• Does not upset nature’s balance;
• Remains in the air for only a short time before nature cycles it into plants, animal tissue, and natural accumulations;
• Does not contaminate apart from nature’s extremely high and concentrated volumes from some volcanoes and then only locally and briefly under rare natural conditions when in concentrations and amounts far higher than anything humans can produce;
• Is not a foreign substance;
• In past more than 130 times higher in conc’, in air than today.

In some locations within nature other atoms can be included with hydrocarbons as impurities in the resource deposit. These can include for example, Sulphur (S) and Nitrogen (N) among others. When these are burned in oxygen they produce sulphur dioxide (SO2) and nitrous oxides (NOx).

Along with particulates that are small particles of soot or smoke, these are real pollutants. Fortunately, real science has led to technology that removes virtually all such pollutants at the source or after combustion of the hydrocarbon fuel.  This is why modern cities in developed countries have clean, healthy air.