Climate Change Will Begin Changing the Color of the Ocean

By Roni Dengler | February 4, 2019 1:36 pm
ocean color

The ocean’s colors could change as the climate warms, though it won’t be very noticeable to the naked eye. (Credit: Ivan Kurmyshov/Shutterstock)

The ocean is rich in diverse shades of blue and green. Now researchers find climate change will alter the color of the oceans by the end of the 21st century. The changes won’t be dramatic, in fact, they likely won’t be visible to the naked eye, but it suggests that the hue of the ocean could be an important marker for scientists watching to see how climate change will affect our seas.

“Ocean color will give us an earlier signal of climate change effects on the marine ecosystem than other things we usually look at,” said Stephanie Dutkiewicz, a biogeochemist at Massachusetts Institute of Technology in Cambridge, who led the new research.

Ocean Blue

The ocean is awash in blue thanks to water. When sunlight hits the ocean, water molecules absorb most of the light, except for the blue part of the spectrum, which is reflected back. In contrast, much of the ocean’s green hues come from phytoplankton, the microscopic plants that provide the foundation of the marine food web.

“Phytoplankton provide the organic matter that feeds almost everything else in the ocean,” Dutkiewicz said. “So if you eat seafood, you care about phytoplankton.” Chlorophyll in phytoplankton reflects green light back instead of blue, making areas abundant with the tiny flora tend toward green.

Climate change will likely alter the types of phytoplankton that abound in future oceans. Since much of the ocean’s color comes from phytoplankton, Dutkiewicz and her team suspected that if these communities change, then the color of the ocean is likely to vary along with them.

Sea Green

To find out how much climate change will influence the ocean’s color, the researchers built a model that simulates how ocean color will shift based on the amount and type of phytoplankton present.

The simulations, which take about three weeks to run on a large array of computers, revealed we can expect our oceans to look a little different in the future, though it depends on where you go. Areas in the subtropics, including much of the Atlantic Ocean, will become bluer, whereas regions near the poles will become greener thanks to shifts in the types and abundance of different kinds of phytoplankton, the team reports today in the journal Nature Communications. In total, climate change will alter at least 30 percent of the ocean’s color by 2100 and perhaps more than 60 percent, the researchers say.

Although optical sensors in satellites will be able to tell the difference, Dutkiewicz notes the naked eye will likely won’t be able to pick up on the color changes. Still, the sweeping alterations to sea life will be significant enough to affect ocean’s food web, which phytoplankton sit at the base of.

Dutkiewicz recommends that future satellite measurements pay more attention to the color of the oceans they’re surveying. As the colors change, so too does the sea of life beneath.

CATEGORIZED UNDER: Environment, top posts
MORE ABOUT: climate change, oceans
  • Uncle Al

    Klimate Kaos? Sacrifice your life today so those who would destroy America are not disappointed. “ the sweeping alterations to sea life will be significant

    … Them ain’t no butterfly wings flapping.

  • Mike Richardson

    Well this is concerning. We knew that coral reefs were suffering from warming oceans, but if more phytoplankton die off than are replaced in warming polar seas, that will only accelerate the imbalance between oxygen and carbon dioxide in our atmosphere. As an organism that breathes oxygen, I have an interest in seeing it not decline.

  • Mark

    They say if you read a book a year you
    will become an expert in 5 years. I’ve been watching sun output for 15
    years. The sun is cooling. Just watch the sun spots. The less Sun spots,
    the less solar out put. We have had zero sun spot off and on for 15
    years. Sol is in a magnetic reversal. Sol has a 200 year cycle of
    cooling. It’s now. The Earth is getting colder. There will be wild
    swings in weather. The Global warming people (who’s government money
    they relies on) say this is because the Earth is warming. I can’t figure
    out how getting colder is cause by global warming and so many drink the
    cool aid? It’s almost a conspiracy to say the opposites to prevent a
    run on food and oil.

    • Mike Richardson

      Nope. Not getting colder, according to NOAA, NASA, NSIDC, or any other agency studying Earth’s climate. Read more.

  • Mark

    Still drinking the cool aid

  • Mark

    Look at the sun and make an opinion.

  • Kurt Stocklmeir

    water does not absorb any color of visible light – water is extreme bad at absorbing any visible light – use bing search – hyperphysics transparency of water in visible range – an extreme small amount of visible light is absorbed by water Kurt Stocklmeir

    • Mike Richardson

      Kurt, please read more basic science before commenting. Unless this is an effort at trolling by creating a character who constantly says things that are obviously wrong, you are only embarrassing yourself. Water absorbs, reflects, and refracts light. The degree to which property dominates depends on many factors, including those discussed in the article.

  • OWilson

    According to the AGW’s (if we have not gone extinct in he meantime) we will have more to worry about a hundred years from now, than an, imperceptible to the human eye, color change of the oceans. :)

    I am surrounded by ocean, which has drastic but beautiful color changes every day, that ranges from dirty grey, to piercing blue, to green, to turqoise, and everything in between. :)

    • Regret

      When your oil light is blinking you have nothing to fear from the light itself, but a lot to fear from the lack of oil it is indicating. The colour of the ocean is the earth’s oil light.


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