Who Cares About Oceans?

October 18, 2015 - 6:16pm

Marika Holland, NCAR Sr. ScientistWe both work in a land-locked state and study the ocean from afar. When people hear that we work on how climate change affects the oceans and sea ice, we often get asked the same question:  “Why should we care about the oceans? “ It’s a hard question to answer, not because the oceans aren’t vital to our well-being, but because for most of us, the oceans are a foreign and misunderstood place.  One’s first impression is that the oceans seem “too big to fail.”  How many times have we heard that 70% of Earth’s surface is ocean?  And the mental image of “ocean” is of a vast, mostly cold and dark, almost outer space like realm.  It’s a great place to visit, but most of us don’t consider the ocean our home, and few have the opportunity to experience it.

But the ocean is a vital part of our greater home, Planet Earth.  Ocean currents move cold and warm water around like giant rivers, often along coastlines and to every depth, and in doing so it plays a huge role in moving heat from one part of the planet to another, regulating our climate. Sea ice, which is really just frozen ocean, is a bright material and reflects sunlight away from the Earth’s surface, thereby influencing the planet’s temperature. As carbon dioxide concentrations rise in our atmosphere, the ocean plays two very important roles.  First, it absorbs about a third of carbon dioxide we put into the atmosphere every year, and this greatly slows down the pace of climate change.  Second, because water has such a high heat capacity and high volume, most of the atmospheric warming that results from climate change (about 90%) ends up in the ocean.  So the oceans are a large essential buffer in maintaining Earth as the habitable place that it is.

However, the consequences of these two big favors that the ocean provides are not benign.  The absorption of carbon dioxide causes the pH of the ocean to decline (“ocean acidification”) and the warming of the ocean itself leads to changes in circulation, nutrient availability, oxygen supply, and very visibly, the progressive melting of the Arctic sea ice. The loss of sea ice in turn contributes to enhanced warming of the globe by reducing the reflectivity of the planet.  

Tortoise, Source: Videoblocks

What’s affected most profoundly by all of these changes of course, is marine life itself, which is every bit as rich and thriving as life on land.  Most of us have difficulty envisioning marine life beyond the megafauna: fish, polar bears, penguins, whales, dolphins; and we particularly view marine life within the narrow confines of what shows up on the restaurant menu.  However, the true vision is that these organisms have complex lives and interactions with their own kind and with other species.  We’re learning that many are much more intelligent than we had imagined.  Over millions of years, they’ve evolved not only as individual species but also as members of complex ecosystems.  The “Balance of Nature” that we learned about as school children and which is so obvious on land is just as important in the marine realm.  Ocean health is basically a reflection of that balance.

So when we are asked about the importance of the oceans, it’s tempting to list the statistics:  in addition to regulating our climate, they provide half our oxygen supply, 20% of the world’s protein, livelihoods and economic support for many millions of people in coastal communities, and so on.  But what gets lost is the fact that the oceans are home to most (50-80%) of the life on our planet.  Perhaps its vastness is better viewed in terms of the millions of years that were required for the living ocean to become what it is, or the astounding biodiversity it supports.  So “Who cares about oceans?” can be both a practical and esoteric question; obviously we should care enough to take actions to reduce our impact. Indeed, to ensure a rich and vibrant ocean for future generations, it will take all of us, working together, to address the ongoing threats to its health.

About the author

kleypas's picture

Joanie Kleypas

Joanie Kleypas is a marine ecologist/geologist in NCAR's Climate and Global Dynamics (CGD) division that focuses on how coral reefs and other marine ecosystems are affected by changes in the Earth's atmosphere and climate.