Sea Science: Water, water everywhere yet not a drop to spare

Oct 27, 2018 by Jordanna Sheermohamed

Sea Science: by Jordanna Sheermohamed

It covers 70 percent of our planet. We play in it, clean with it, cook with it and essentially use it to simplify our everyday lives. Human survival is bounded by the “3-3-3” rule, meaning we can survive 3 minutes without oxygen to the brain, 3 days without water, and 3 weeks without food.

Unless we somehow evolve into a species with salt-water gills, fresh water is key for human survival. But many of us often don’t stop to think about where the water we use originates, where it goes once we dispose of it and, most importantly, how much of it is available?

The harsh truth is there is a finite amount of water moving through the Earth’s biospheres. The water cycle expertly illustrates several reservoirs where the earth’s water is located, in various phases:

  • As liquids in rivers, oceans, streams, lakes and aquafers.
  • In solid form, such as glaciers, snow and ice.
  • In gas form as water vapor, cycling through the Earth’s atmosphere.

So when water is moved from one reservoir to the next via a transport mechanism – such as evaporation, condensation, melting or freezing – it essentially moves through some part of the hydrological process. Its “residence time” in each reservoir can be determined by the size of the reservoir (think puddle versus ocean) and exposure to elements (winds that can enhance evaporation or humidity that reduces evaporation).

Theoretically, a single drop of water will move through the water cycle an infinite number of times. For instance, water evaporating from the oceans could move inland via onshore winds, sometimes condensing into a precipitation producing cloud along the coast, or sometimes moving far enough inland to become snow over a mountain top. A single snowflake could melt during the spring, flow downstream during a raging thunderstorm and infiltrate the soil of a farm, eventually producing the orange that gets squeezed into your Sunday brunch mimosa.

In fact, ice core samples extracted from the depths of arctic glaciers can be analyzed to indicate the water vapor content of the atmosphere during the time the sample was created.

Water that infiltrates the ground slowly trickles through combinations of soil, rocks, clay and sand, which extract impurities from the water. The “filtered” water generally finds its way into aquifers and other underground water systems before eventually making its way back into the ocean. This natural filtration process provides water that is ideal for human consumption, barring any additional impurities as a result of human activity.

Sensible and respectful water use should be something everyone considers, because it takes time to recharge the aquifer and wells many people have come to depend on for their everyday water use.

We often think of water as being infinitely available, but the truth is human consumption should take a more “limited availability” approach. For example, if you had five gallons of water to spend, how would you spend it – a single cup of coffee, a toilet flush, an extra minute in the morning shower?  Keep in mind, once a “purchase” has been elected for the five gallons, it’s no longer available to “spend.”

As mentioned above, there is a finite amount of water within Earth’s biospheres, and taking it from one source means removing it another.

When examining the current distribution of water sources within the Earth’s biospheres, 97 percent is saltwater, 2 percent is frozen, and the remaining 1 percent is accessible as fresh water. If we applied the same budgeting thought process to water as we did our finances, we’d become a lot more conscious of preserving that precious 1 percent.

Jordanna Sheermohamed is president and lead meteorologist of Weather Forecast Solutions, a weather-forecasting firm (  Comments are welcome below.


About Jordanna Sheermohamed

Jordanna Sheermohamed is president and lead meteorologist of Weather Forecast Solutions, a private weather-forecasting company ( Comments are welcome at

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