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Why 1 Degree Matters

Bethany Gaffey

This week on Too Hot to Handle, we dive into some fun facts about water, why they matter, and how it all ties into ocean warming.

If you’ve ever heard about ocean temperatures rising by 1 degree and thought, “So what? What’s the big deal about 1 degree?” then this article is for you. The fact is that while 1 degree doesn’t sound like much, the consequences on the ocean are far bigger than you might expect.

To understand the impacts of ocean warming, one must first understand the basic properties of water and what exactly makes this element so important to our planet.

The Wonders of Water

Water has a lot of wondrous qualities, but to spare you some time (and a long lecture in chemistry), I’ll narrow it down to a few fun facts:

  1. Water is the only element on earth that can naturally be found in all three states – solid, liquid, and gas.

  2. Water covers about 71% of the surface of Earth.

  3. Water makes up about 55-60% of our bodies.

  4. Water has a high heat capacity, which means it can absorb a LOT of heat before its temperature rises.

While these all may be interesting facts, the most important fact for the purpose of this article is number four.

The Atlantic Ocean. Photo: Bethany Gaffey

Planet Water?

If water is so important and makes up the majority of both our bodies and our planet, then why is our planet named “Earth”? It is for the exact same reason that when one hears the words “1 degree” they imagine air temperature. As humans, we best understand the world around us by what we are familiar with, or what is most relevant to us. Why name the planet “water” if we live on the earth and the ocean is both vast and mysterious? Why think that 1 degree is a big difference in water if it isn’t in air? This all ties back to fun fact number four - water has a high heat capacity.

To put things in perspective, let’s consider scuba diving. Living in north central Florida means that many of my dives take place in natural springs, where the water is sourced directly from the aquifer and remains a constant 72 degrees Fahrenheit year-round. Because water is a much better absorber of heat than air, I can lose my body heat about 25 times faster underwater than on land. For that reason, I have to wear much more thermal protection in 72 degree water than I would in 72 degree air. So what does this whole heat capacity thing really mean for our planet?

Left – Me preparing for a dive in 72-degree spring water with a 5mm wetsuit and hooded vest. Right – Blue Grotto Dive Resort in Williston, FL. Photo: Bethany Gaffey

Water Sustains Life on Earth

Have you ever heard the phrase, “warm air rises”? This fact applies to water as well. The combination of the movement of ocean currents, the rising of warmer water and the falling of cooler water, and the heat capacity of the ocean is what essentially makes life possible on Earth. Large bodies of water moderate the Earth’s temperature so well that plants and animals can thrive here. A lot of this can be explained by the chemistry of water molecules, so to keep things simple let’s think of a real-world comparison. Consider the planet Mars. There are many reasons we have yet to inhabit our red, dusty neighbor, but one of the biggest reasons is water. Without great swaths of water, like Earth’s oceans, the temperature on Mars averages at -81 degrees Fahrenheit, with major temperature fluxes between night and day, as well as between the equator and the poles. Also, let’s not forget that practically every life form on Earth requires water to survive. So, how does this all tie back to ocean warming?

Photo: Pixabay

Why 1 Degree Matters

Now that we've touched on why heat capacity is important, we can explain why an ocean temperature rise of 1 degree is much bigger than it sounds. First of all, remember that water must absorb lots of heat before it actually rises in temperature itself. Next, consider how vast the oceans are and how much water they contain. Now, try to imagine how much heat it would take to make all of the ocean water on Earth collectively rise 1 degree. The answer is a LOT.

Going back to basic chemistry, when a substance is heated, its molecules move faster. In water’s case, this heating leads to literal expansion, referred to as thermal expansion. This means that as the ocean heats, water expands, sea levels rise, and ice caps begin to melt, adding even more water to the mix. Nearly 40% of people on Earth live within 60 miles of the coast, which is the first place rising seas will impact. And that is exactly why 1 degree matters.

Photo: Pixabay


Too Hot To Handle, part of our Research Series, highlights recent research efforts into ocean warming and its effect on marine life


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