UNIT 5 The Villain in the AtmosphereThere is one gas present in the air we breathe that is essential to life. Unfortunately,one can have too much of a good thing and the growth in carbon dioxide threatens towarm up our to a dangerous extent. Isaac Asimov introduces us to this villain inthe atmosphere, explaining how it works and what can be done about villain in the atmosphere is carbon does not seem to be a villain. It is not very poisonous and it is present in theatmosphere in so small a quantity — only percent — that it does us no ’ smore, that small quantity of carbon dioxide in the air is essential to absorb carbon dioxide and convert it into their own tissue, which serve as the basicfood supply for all of animal life (including human beings, of course). In the process theyliberate oxygen, which is also necessary for all animal here is what this apparently harmless and certainly essential gas is doing to us:The sea level is rising very slowly from year to year. In all likelihood, it will continueto rise and do so at a greater rate in the course of the next hundred years. Where there arelow- lying coastal areas (where a large fraction of the world ’ s population lives) the waterwill advance steadily, forcing people to retreat the sea will reach two hundred feet above its present level, and will besplas