The earth has undergone a number of dramatic changes over its history and is still doing so today. But what was it like billions of years ago?
What was Earth like 2 billion years ago?
To modern humans, Earth would look like a planet devoid of life. This is because modern cells, which are many thousands of times larger than primitive cells, didn’t evolve into existence until 1.5 billion years ago. Only then could animals and plants start along their evolutionary paths.
Primitive cells similar to modern cyanobacteria and archaea were pretty much everywhere 3.5 billion years ago. Still, you wouldn’t see them because, like today, they were too small. Oxygen in the atmosphere did not exist.
An ice age that lasted hundreds of millions of years ended 2.1 billion years ago. With the global warming that followed, some cells developed abilities to photosynthesize and excrete oxygen. Oxygenation of the atmosphere was well on its way in year 2 billion. Eventually, this oxygen would kill almost all life on Earth. What survived became us.
The largest meteor impact in world history occurred in South Africa, almost exactly 2 billion years ago. However, what impact it had on the weather is not known.
What was the Earth like two billion years ago?
The day was 20 hours long, and the year was 450 days. The moon was 30,000 miles closer to Earth. It would have looked larger than now and had a more substantial effect on ocean tides.
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The crust of the Earth was more active than now. As a result, volcanic activity and earthquakes were more common.
The Earth’s magnetic field was half what it is today. The solar wind stripped the atmosphere more effectively, which probably accelerated the turnover of Earth’s atmosphere from anaerobic to aerobic. This was to intensify and accelerate the extinction from toxic oxygen increasing in the atmosphere.
The color of the sky would be bluer and less purple than today due to lower levels of oxygen and higher nitrogen levels. The Earth would have no green plants or any other vegetation to add to the many colors seen everywhere today.