Falling oxygen levels caused by global warming could be a major threat to the survival of life on planet Earth, according to new research. A new paper suggests that falling oxygen levels are one overlooked but potentially serious outcome of climate change.

In a study, publication of which coincides with high level climate talks in Paris, University of Leicester applied mathematics professor Sergei Petrovskii has warned 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 stop oxygen production by phytoplankton by disrupting the process of photosynthesis.

This could drastically reduce the amount of oxygen being produced around the world.

Although some have suggested that higher atmospheric CO2 concentrations might lead some crop plants to grow faster, research published over the past few years has shown that plants’ ability to absorb CO2 has been overestimated and that higher atmospheric levels of the greenhouse gas may also hamper key food crops' uptake of nutrients.

Professor Petrovskii explained, "Global warming has been a focus of attention of science and politics for about two decades now. A lot has been said about its expected disastrous consequences; perhaps the most notorious is the global flooding that may result from melting of Antarctic ice if the warming exceeds a few degrees compared to the pre-industrial level. However, it now appears that this is probably not the biggest danger that the warming can cause to the humanity.

"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."

Petrovskii’s team used computer modelling to look at oxygen production in the earth’s oceans. They said that, as carbon dioxide is the main agent in global warming, most research has tended to focus on the CO2 cycle, whilst few researchers have explored the effects of global warming on oxygen production.

Provisional figures, released late last month by the UN’s World Meteorological Organisation ahead of the CoP21 talks in Paris, showed ocean surface temperatures were at record highs in 2015, breaking the previous record, which was set in 2014.