Dynamics of atmospheric oxygen under anthropogenic stresses

We analyse proxy and observed data of atmospheric oxygen (ten contemporary records over the globe) and demonstrate its nonlinear decline, which is small but of uncertain decline rate. This decline was previously thought to be linear and caused mainly by use of fossil fuels (combustion), but by reviewing anthropogenic interventions we list more than a dozen smaller-scale processes that utilise oxygen in various forms. We have identified and quantified a previously unaccounted sink of atmospheric oxygen that serves multiple industries. This sink grows nonlinearly and has already exceeded the natural weathering deoxygenation. It has also been confirmed by means of comparison of the projection of oxygen decline with carbon emissions in the IPCC scenarios. We discuss the updated oxygen budget, possible solutions for the mitigation of the oxygen sink, and future dynamics of atmospheric oxygen.

[1] Livina et al, Tipping point analysis of atmospheric oxygen concentration, Chaos 25, 036403 (2015).

[2] Livina & Vaz Martins, The future of atmospheric oxygen, Springer Nature, in press.