00:00Earth's oxygen-rich atmosphere is temporary, on a cosmic timeline.
00:05Every breath makes it seem like oxygen has always been here, and always will be.
00:10But scientists say Earth's oxygen-rich atmosphere is temporary on a planetary timeline.
00:16Not temporary like next year.
00:18Not temporary like next century.
00:21Temporary like roughly a billion years from now.
00:24NASA-supported research modeled Earth's far future and found that oxygen could eventually
00:28crash to a small fraction of today's level.
00:31The cause is not one sudden disaster.
00:34It is the slow aging of the sun, and the long-term chemistry of the planet.
00:39As the sun grows brighter over time, Earth's climate and carbon cycle change.
00:44Carbon dioxide could eventually fall to levels too low for many photosynthetic organisms to
00:49keep producing oxygen at modern levels.
00:53When that happens, the atmosphere could shift dramatically.
00:56For humans, the important correction is this.
01:00Breathable air is not in immediate danger.
01:03This is not a warning to panic about tomorrow.
01:06It is a glimpse into Earth's deep future.
01:09But it is still humbling.
01:12The oxygen we breathe came from life.
01:15Tiny photosynthetic organisms transformed the planet billions of years ago, filling the atmosphere
01:20with the gas that made animals like us possible.
01:23breathable.
01:24That means our world is not just a rock with air.
01:28It is a living chemical system.
01:30And like every system, it has a history and a future.
01:35One day, far beyond any human civilization we know, Earth may become a planet where complex
01:40oxygen-breathing life can no longer survive.
01:43That does not make today's life meaningless.
01:46It makes it more extraordinary.
01:49For one chapter in cosmic time, Earth became breathable.
01:52And we are living inside that rare window.
01:56Do motor
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