Climate change is having an increasing impact on us, our nature and the oceans. The rapid melting of the ice caps at the North and South Poles is causing sea levels to rise rapidly, while climate-related natural disasters are becoming more frequent – ten times more frequent than just a few decades ago, according to Welthungerhilfe.
Marine animals are also entering areas they have not previously visited. This is partly due to the severe lack of oxygen in the water.
But now researchers have discovered another effect on the seas: the oceans change their color.
Seas are getting greener
The water in our oceans is not only getting warmer, but also greener. That’s according to a new study published in the science journal Nature, which analyzed 20 satellite images from NASA.
The result: 56 percent of the seas have changed their color palette significantly. Especially for tropical regions around the equator.
The reason: marine organisms such as phytoplankton.
How does the green color come about?
Phytoplankton contain the pigment chlorophyll, which reflects green light, so the ocean is usually greener when it contains more populations of the marine microbes.
The authors of the study explain that the plankton scatter and absorb light differently, affecting the optical properties of the water and thus changing the perceived color of the ocean. If the level of reflection changes, it also means that the ecosystem changes.
The authors believe that the possible origin of this change lies in climate-induced nutrient stratification in upper ocean waters, which could cut off the food sources for these organisms.
“More stratification means a greater difference in density between the surface water (where the light is) and the deep water (where the nutrients are), which means less mixing of the two, so less nutrients reach the plankton.”
– BB Get
20 years of satellite imagery analyzed
Researchers at the National Oceanography Center in Southampton have analyzed observations made by NASA’s Modis-Aqua satellite over the past 20 years.
You’ve been looking for patterns that show the changing hues of the oceans, including reds and blues. The observed changes are clearly visible when compared to a computer model that simulates what the oceans would look like if human-caused global warming did not exist.
Accordingly, in most areas it is clear that our oceans are becoming ever greener.
Why should we care?
While we’re probably all fans of the classic blue sea, there’s nothing inherently wrong with the color green. But the green color clearly shows that the ecosystem of the sea is changing.
It should be noted that phytoplankton pulls carbon from the atmosphere and, as a producer of atmospheric oxygen, plays an essential role for all life on earth.
They also have the ability to change much of their environment, including temperature, nutrient availability, and water light levels, and are the foundation of the marine food chain. For all of these reasons, it’s important to know exactly what’s happening to them and what we can do about it.
So the blue planet is slowly turning into a green one. How do you feel about the oceans getting greener and greener? Tell us in the comments!