Researchers reveal how Earth’s oxygen could collapse with ocean warming of just 6 degrees C. Such as collapse is a far greater threat than the threat of sea level rise and flooding.
A study of ocean plankton led by Sergei Petrovskii, Professor in Applied Mathematics (specializing in ecological mathematics) from the University of Leicester’s Department of Mathematics, has shown that an increase in the water temperature of the world’s oceans of around six degrees Celsius – which some scientists predict could occur as soon as 2100 – could disrupt the process of photosynthesis and so stop oxygen production by phytoplankton.
About two-thirds of the planet’s total atmospheric oxygen is produced by ocean phytoplankton – and therefore cessation would result in the depletion of atmospheric oxygen on a global scale. This would likely result in the mass mortality of animals and humans.”
Additional support for the model comes from direct measurement of a mysterious decline of oxygen in the atmosphere. Within the past several years scientists have found that oxygen (O2) in the atmosphere has been dropping, and at higher rates than just the amount that goes into the increase of CO2 from burning fossil fuels, some 2 to 4-times as much, and accelerating since 2002-2003. Simultaneously, oxygen levels in the world’s oceans have also been falling in an expanding fashion for the past fifty years, and will continue into the foreseeable future.
The fundamental cause of oxygen decline in the oceans that has not been mentioned in many studies is the failure of phytoplankton in the oceans to regenerate oxygen by photosynthesis. Phytoplankton is responsible for most of the primary productivity in the oceans that supports the entire marine food web and accounts for the majority of the planet’s primary production from photosynthesis.
Article: Mathematical Modelling of Plankton–Oxygen Dynamics under Climate Change
Bulletin of Mathematical Biology
Russ George: 17 June 2016