A new research has revealed that the amount of atmospheric oxygen has dropped over the past million years or so. Is it something to be worried about?

Scientists of Princeton University gathered some ancient ice core samples from Antarctica and Greenland to explain this drop. Their findings were published in the journal Science.

In detail, the world has lost 0.7 percent atmospheric oxygen over the past 800,000 years. Even more alarming is the oxygen sink, processes that removed oxygen from the air, are even consuming bigger what the sources of oxygen have given out; 1.7 percent to be exact.

According to the researchers, there are two possible reasons for this. First, it is because of the increasing amount of pyrite by either Neogene cooling or increasing Pleistocene erosion rates over the past years.

Erosion exposes pyrite and other organic carbon into air. Previous studies have shown pyrite and organic carbon react with oxygen, causing it to be absorbed from the air.

Another explanation is the increasing microbe activity of ocean-consuming organisms, as brought by a cooling ocean.

"Alternatively, when the ocean cools, as it has done over the past 15 million years, before fossil fuel burning, the solubility of oxygen in the ocean increases. That is, the oceans can store more oxygen at colder temperatures for a given concentration of oxygen in the atmosphere," University geologist Daniel Stolper told Live Science.

As a result, oxygen-dependent microbes in the ocean and in sediments (areas that are often with less oxygen) can then become more dynamic and their rates of consuming this oxygen will become ultimately high, leaving less of it in the atmosphere.

Talking to Gizmodo, Stolper also said long term climate change could drive more cooling oceans.

So, is this something the people depending on oxygen should be worried about? Stolper told Gizmodo although we are consuming oxygen at a rate a factor of a thousand times faster than before, we are still not running out of oxygen to breathe, noting in the study that the depletion of oxygen is comparable to riding an elevator to the 30th floor of a building.