How much water is there on Earth?

The planet holds an incredible amount of water! So, how much water is on Earth? Well, it's estimated to be around 326,000,000,000,000,000,000 gallons (that's 326 million trillion gallons), or approximately 1,260,000,000,000,000,000,000 liters.

This water follows a continuous cycle — it evaporates from the ocean, moves through the atmosphere, falls as rain on the land, and eventually returns to the ocean.

In this article, we will dive deeper into the Earth's water, exploring both the fresh and salt water that make up the Blue Planet.

Salt Water on Earth

The oceans are immense, covering about 70% of the Earth’s surface, with an average depth of around 12,100 feet (3,688 meters). Roughly 97% of the water on the planet is contained within the oceans, and it is unsuitable for drinking due to its salt content.

The Pacific Ocean is by far the largest ocean, capable of containing all the continents. It is followed by the Atlantic Ocean, the Indian Ocean, the Southern Ocean, and the Arctic Ocean.

Earth's Freshwater

Less than 3 percent of the water on Earth is fresh, with around 1.6 percent of it frozen in polar ice caps and glaciers. Another 0.36 percent resides underground in aquifers and wells.

Only about 0.036 percent of the Earth’s total water is surface water found in freshwater lakes and rivers. While that's still thousands of trillions of gallons, it represents a tiny fraction compared to the total water available.

Now That's a Lot o' Lakes

The world is home to 117 million lakes, covering nearly 4% of the Earth's land area (excluding Greenland and Antarctica's glaciers). The United States has 1,681 lakes, but the largest freshwater lake by both volume and depth is Lake Baikal in Russia.

Water Is Everywhere

The remaining water on Earth exists as clouds, water vapor in the air, in plants and animals, or as moisture in the soil. Your body itself is made up of 65% water, so if you weigh 100 pounds, 65 pounds of that is water.

With all the soda, milk, and orange juice in stores and fridges, there are likely billions of gallons of water just sitting on the shelves at any given moment!

Drinking Water in the United States

In the United States, drinking water is sourced mainly from two places: surface water and groundwater. Surface water comes from reservoirs, lakes, and rivers, while groundwater, found in aquifers beneath the Earth's surface, also provides a crucial supply, particularly in rural and sparsely populated areas.

Both of these water sources undergo extensive treatment to meet the high-quality standards established by the Environmental Protection Agency (EPA) before the water reaches homes and businesses for use.

The Water Cycle

The water cycle, also referred to as the hydrologic cycle, is an ongoing process that illustrates how water moves across, above, and below the Earth's surface. It is crucial for redistributing and replenishing Earth's water supplies.

The cycle starts with evaporation, where the Sun's heat turns water from oceans, rivers, and lakes into vapor that rises into the air. This vapor then condenses to form clouds. Next comes precipitation, where droplets in the clouds combine and fall as rain, snow, sleet, or hail.

Some of this water returns to water bodies through runoff, while some infiltrates the ground. The evaporation of runoff restarts the cycle.

The Effects of Climate Change

Climate change affects the water cycle, disrupting its natural flow. It leads to rising sea levels and changes in precipitation, causing heavier rainfall in some areas and extended droughts in others.

Climate change can also impact the quality of water, influencing the levels of pollutants and contaminants in lakes, rivers, and other bodies of water.