What If Earth Was Half Land and Half Water?

Imagine a scenario where Earth maintains a perfect 50/50 division between continents and oceans. Our planet would feature an equal distribution of land and water across its surface. This transformation would bring about substantial changes to Earth as we know it. It would also usher in novel vacation opportunities, and surprisingly, even impact the color of urine.

Water is an absolute prerequisite for sustaining life on any celestial body. Consequently, the search for extraterrestrial life focuses on planets with the potential for liquid water. On Earth, approximately 71% of the surface is covered by water, primarily within its five interconnected oceans. These oceans collectively constitute a single global ocean. However, if nearly a quarter of this ocean water were to be replaced by land, how rapidly would our planet transition into a barren celestial body devoid of life?

Due to ongoing global warming, sea levels on Earth are currently rising. However, to achieve a perfect balance between land and water, sea levels would drastically decline—by roughly three kilometers. This transformation would give rise to a drastically altered Earth. Both polar regions would desiccate entirely, and every continent would expand significantly. The combined newly emerged landmasses would approximate the current surface areas of Asia, Europe, Africa, and North America combined. This abundance of new territory would present an immense expanse of untapped space. The former coastlines would transition into relatively flat terrain, while areas once submerged in the deep ocean would reveal expansive valleys and steep chasms.

Exploring this reshaped world, one would notice the disappearance of the single global ocean. Instead, distinct oceans would be isolated from each other, and the continents would coalesce into a unified landmass. This transformation would offer evolutionary advantages. In early human history, travel was limited to walking; our ancestors migrated across the globe. Departing Africa approximately 70,000 to 100,000 years ago, they reached Europe and Asia. Eventually, they crossed a land bridge connecting Asia to the Americas, possibly as far back as 20,000 years ago. With a balanced 50/50 distribution, human mobility would expand significantly, enabling the realization of global journeys solely on foot.

However, this shift in the balance between land and water would entail more than just recreational benefits. The reduced water coverage on Earth's surface would disrupt ocean currents, severely destabilizing the climate. These currents distribute absorbed oceanic heat globally. Their disruption would lead to colder temperatures at the poles and amplified heat in equatorial regions. This disruption would expedite climate change as oceans would struggle to absorb carbon dioxide from the atmosphere. Excess carbon dioxide would lead to a planetary thermal blanket, elevating temperatures. Reduced rainfall would follow, resulting in perilous droughts and the emergence of new deserts in inland areas. While vast new land masses would be available, a considerable portion of Earth could become uninhabitable. Adaptation strategies for plants, animals, and humans would become imperative, necessitating reduced dependency on water or enhanced water use efficiency. The resulting water scarcity could drive animals to evolve into smaller sizes, with more species adopting a strictly carnivorous diet. Regrettably, the abundant marine life supported by today's oceans would encounter challenges to their survival.

Perhaps the most unexpected outcome to acclimate to would be a significant change in the composition of urine. Normally composed of over 90% water, urine would darken and adopt an ammonia-like smell due to the reduced water availability in daily life. While this scenario pales in comparison to the extreme possibility of entirely draining Earth's oceans, that narrative remains a tale for another time.

And so, this thought imagination paints a vivid picture of a transformed world, showcasing the intricate balance between land and water that underpins Earth's remarkable ecosystems and the delicate dance of life itself.