The most creative way to transform the Earth into something like Venus
If it were possible, an original way would be to invert earth topography, so that the emerged lands become oceans and vice versa.
This is what the Earth would look like if something like this really happened:
The ocean floor, which is nothing more than a vast plain situated an average of 3,700 meters below sea level, would mostly become a large plateau located well above the average altitude at which humans live, with much inferior oxygen levels and atmospheric pressure.
The total amount of water on Earth would be greatly reduced, and apart from few slightly deeper areas where mountain ranges used to be, it would be distributed almost exclusively across four shallow oceans.
Since only about 30% of the Earth would be covered with water, less evaporation would take place and consequently rainfall would decrease.
And since the vast majority of the land mass is very far from the sea, which helps to regulate temperature, a huge percentage of the mega continent would become a very hot and dry desert.
Furthermore, a very important function of the ocean is to absorb carbon dioxide from the air, both through microorganisms (algae and phytoplankton) and by diffusion.
With so little water, the oceans would no longer be able to do this, so CO2 would gradually build up in the atmosphere.
This would make the planet hotter and hotter, while that same heat consumes what little ocean is left, triggering a positive feedback loop that ultimately dries up all the remaining seas and leaves behind a planet with a huge greenhouse effect.
And since both the surface gravity and the size of Venus are quite similar to that of the Earth, eventually the two planets would become almost indistinguishable.