Compared to prehistoric times, the level of oxygen in the earth's atmosphere has declined by over a third and in polluted cities the decline may be more than 50%. This change in the makeup of the air we breathe has potentially serious implications for our health. Indeed, it could ultimately threaten the survival of human life on earth, according to Roddy Newman, who is drafting a new book, The Oxygen Crisis.
Read more: https://www.theguardian.com/commentisfree/2008/aug/13/carbonemissions.climatechange