Scientists Warn Earth's Oxygen Supply Will Start Declining Much Sooner Than Expected

Oxygen is the invisible lifeline that allows life to flourish on Earth. We breathe it, plants produce it, and it forms part of the planet’s protective shield against harmful radiation. However, according to a new NASA-supported study, this life-sustaining gas will not be here forever.

Researchers have concluded that Earth’s oxygen-rich atmosphere is destined to collapse within the next billion years. While that may seem impossibly far in the future, the early stages of this decline could begin in as little as 10,000 years.

"The lifespan of oxygen-rich atmospheres may be shorter than we previously thought," said Christopher Reinhard, a co-author of the research from the Georgia Institute of Technology.

The Sun’s Role in Oxygen’s Disappearance

The study, carried out by scientists from NASA and Japan’s Toho University, examined the delicate balance between Earth’s oxygen levels and the Sun’s gradual warming. Our Sun, like all stars, is slowly getting brighter over time. As its luminosity increases, so does Earth’s temperature.

This warming triggers a critical problem: carbon dioxide in the atmosphere begins to break down at a faster rate. Carbon dioxide is not only a greenhouse gas; it is also essential for photosynthesis, the process plants use to produce energy and, in turn, oxygen. Without enough carbon dioxide, plants cannot survive.

If plants disappear, the consequences are dire. With no major oxygen producers left, the planet will begin to lose the thick, breathable atmosphere we take for granted.

A Dangerous Chain Reaction

The researchers warn that the decline in plant life will trigger a cascade of events. Oxygen levels will start to drop, which will weaken and eventually destroy the ozone layer. Without the ozone layer’s protection, harmful ultraviolet radiation from the Sun will reach Earth’s surface in much higher doses.

At the same time, methane—a powerful greenhouse gas—will start to accumulate. "High concentrations of methane, low levels of CO2, and the absence of an ozone layer" will define Earth’s atmosphere, according to lead researcher Kazumi Ozaki.

These changes will create an environment so hostile that most life forms, including humans, will not be able to survive. Oxygen levels could plummet to a million times lower than today, making our current atmosphere unrecognizable.

Understanding the Psychology of Long-Term Threat Perception

Research indicates that humans often find it challenging to comprehend and emotionally react to long-term threats, such as the gradual decline of Earth's oxygen supply. This phenomenon can be attributed to a cognitive bias known as 'temporal discounting,' where future rewards or threats are undervalued compared to immediate ones. As noted by Gretchen Rubin, happiness researcher, "People often prioritize short-term satisfaction over long-term consequences, which can lead to inaction on critical issues." Consequently, despite the seriousness of the decline, it may not elicit a strong emotional response or prompt immediate action.

The researchers warn that the decline in plant life will trigger a cascade of events.

Who (or What) Might Survive

Although humans and animals that depend on oxygen would not last in this new world, some forms of life might endure. Anaerobic microorganisms, which do not require oxygen, could thrive in the toxic air. In fact, this would not be the first time Earth has hosted such an atmosphere.

Billions of years ago, before the Great Oxidation Event, our planet’s air was low in oxygen and rich in gases that would be poisonous to us today. That ancient shift eventually transformed the planet, making it suitable for the oxygen-breathing life we know.

Billions of years ago, before the Great Oxidation Event, our planet’s air was low in oxygen and rich in gases that would be poisonous to us today.

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Not Caused by Human Activity

One important point from the research is that this future decline is not the result of human-driven climate change. It is part of Earth’s natural evolutionary cycle. The warming that will trigger the oxygen loss is due to the Sun’s inevitable increase in brightness over hundreds of millions of years.

That said, the researchers stress that the process will be irreversible once it begins. The decline predicted to start in about 10,000 years will set the planet on a one-way path toward a very different atmosphere.

Earth is fragile

A Reminder of Earth’s Fragility

By the time Earth’s oxygen collapse occurs, scientists believe humans—or whatever might evolve from us—are unlikely to still exist. However, the research serves as a reminder of the temporary nature of life-supporting conditions.

The Earth we know today, with its oxygen-rich atmosphere and thriving ecosystems, is the result of billions of years of change. It is not a permanent state.

For now, that knowledge may give us a deeper appreciation for the conditions that make life possible today and why protecting our planet matters, even if its ultimate fate is written in the stars.

From a social perspective, this finding is concerning. If society fails to take the necessary steps now because of short-term thinking, future generations will face the consequences. Psychologist Robert Gifford refers to these barriers to action as 'dragons of inaction' (Gifford, 2011). These dragons include limited cognition about the problem, ideologies that conflict with the need to act, and perceived risks of change.

Applying Psychological Concepts to Promote Action

To encourage proactive behavior, researchers suggest using 'nudging.' This concept, articulated by behavioral economist Dr. Dan Ariely, involves subtly guiding individuals toward beneficial decisions without limiting their freedom of choice. Dr. Ariely states, "Nudges can help people make better choices by structuring their environment in a way that promotes positive behavior." This approach has been applied in various fields, including environmental conservation, to promote behaviors that benefit both individuals and society at large.

Analysis & Alternative Approaches

Understanding the psychological barriers that prevent us from addressing long-term threats can help us devise strategies to overcome these obstacles. By integrating insights from psychology, such as temporal discounting and nudging, we can better communicate the urgency of the situation and prompt necessary action, ensuring a better future for coming generations.