What would happen if more than 90 percent of the earth’s surface was land?

Giuseppe Frisella
3 min readFeb 12, 2024

If the Earth’s surface were 10% covered with water instead of ~70%, then the planet would be going through geological and/or astronomical phases that would already be making our time on this planet very uncomfortable.

The Earth’s surface would look something like this:

Actually, here I have simply lowered the mean sea level by 5,000 meters.

Possible (and plausible) causes:

Scenario 1. Earth is heading toward an out-of-control greenhouse effect like the one that characterizes Venus.
This will happen in one to two billion years, however, with increased solar activity triggering a positive feedback loop of rising temperatures.
Since the Earth has a magnetic field, however, water is not broken down by the Sun, but the increase in temperature results in substantial evaporation.
I believe that 10% liquid water on the surface may correspond to a planet still habitable for us humans, at least far from the tropics. I cannot determine whether extreme weather phenomena can occur in this situation.
It is perhaps what the situation will be in 650–700 million years.



Giuseppe Frisella

I'm a curious person and I'm on Medium mainly to read and share thoughts and knowledge. I love science, especially physics and evolutionary biology.