A new study revealed that the Earth is slowly losing oxygen and the increased amount of carbon dioxide brought about by burning massive amounts of fossil fuels in the last 100 years is partly to blame.

The study, published in the journal Science, revealed that the oxygen concentration in the Earth's atmosphere have decreased by 0.7 percent in the last 800,000 years. The decline is not that significant to be worried over. However, scientists are concerned because that the concentration of oxygen in the atmosphere has rapidly dropped by 0.1 percent in the last century.

"We are consuming O2 at a rate a factor of a thousand times faster than before," said Daniel Stolper, a geologist at Princeton University and lead author of the study, in a report from Gizmodo. "Humankind has completely short-circuited the cycle by burning tons of carbon."

Scientists noted that the increase carbon dioxide in the atmosphere is not the only probable cause of the decline in oxygen levels. However, it most likely contributed a lot in the decreasing tread.

Other possibilities that the researchers are looking into is the speeding erosion rates in the recent years and decline in global temperatures.

The increased global erosion rate, which is believed to be caused by the rapid glacial to interglacial periods, could decrease the concentration of oxygen in the atmosphere in a similar way how nails rust. When a nail is rusting, iron binds with oxygen during oxidation. On the other hand, more sediment are exposed during erosion and oxidized by the atmosphere, causing more oxygen to be consumed.

When the human-induced global warming is taken to the side, the researchers noted a bit of decline in the planet's average global temperature in the past few million years. As the ocean cools, oxygen in the atmosphere becomes more soluble. This means that more organic carbon in the ocean will be oxidized and lesser oxygen will be returned back to the atmosphere.

While the researchers noted that the Earth will not run out of oxygen anytime soon. But, their findings clearly show how human activities could affect what happens in the planet naturally.