title: The human physiological impact of global deoxygenation.
abstract: There has been a clear decline in the volume of oxygen in Earth's atmosphere over the past 20 years. Although the magnitude of this decrease appears small compared to the amount of oxygen in the atmosphere, it is difficult to predict how this process may evolve, due to the brevity of the collected records. A recently proposed model predicts a non-linear decay, which would result in an increasingly rapid fall-off in atmospheric oxygen concentration, with potentially devastating consequences for human health. We discuss the impact that global deoxygenation, over hundreds of generations, might have on human physiology. Exploring the changes between different native high-altitude populations provides a paradigm of how humans might tolerate worsening hypoxia over time. Using this model of atmospheric change, we predict that humans may continue to survive in an unprotected atmosphere for ~3600 years. Accordingly, without dramatic changes to the way in which we interact with our planet, humans may lose their dominance on Earth during the next few millennia.
authors.affiliation: UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, University College London Centre for Altitude Space and Extreme Environment Medicine, First Floor, 170 Tottenham Court Road, London, W1T 7HA, UK. daniel.martin@ucl.ac.uk.|Intensive Care Unit, Royal Free Hospital, Pond Street, London, NW3 2QG, UK. daniel.martin@ucl.ac.uk.|Royal Free Hospital, University College London Division of Surgery and Interventional Science, Pond Street, London, NW3 2QG, UK. daniel.martin@ucl.ac.uk.
authors.forename: Daniel
authors.initials: D
authors.lastname: Martin
authors.affiliation: UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, University College London Centre for Altitude Space and Extreme Environment Medicine, First Floor, 170 Tottenham Court Road, London, W1T 7HA, UK.|Royal Free Hospital, University College London Division of Surgery and Interventional Science, Pond Street, London, NW3 2QG, UK.
authors.forename: Helen
authors.initials: H
authors.lastname: McKenna
authors.affiliation: National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, UK.
authors.forename: Valerie
authors.initials: V
authors.lastname: Livina
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D001272:Atmosphere / Q000737:chemistry*; D018534:Earth, Planet; D006801:Humans; D008962:Models, Theoretical; D010100:Oxygen / Q000032:analysis*
chemical_list: D010100:Oxygen
keywords: Acclimatization; Hypoxia; Oxygen; Physiological adaptation