NASA satellites show that more than half of the Earth’s oceans are turning green due to climate change disrupting marine ecosystems. According to satellite data, over the past 20 years, 56% of the world’s oceans have changed color from blue to green. These changes are especially noticeable in tropical regions near the equator.
This subtle greening of the oceans indicates that climate change is affecting life underwater, researchers say.
Why does the ocean turn green?
NASA’s Modis-Aqua satellite recorded a gradual transition from blue to a predominantly green hue in more than half of the world’s oceans. The area that changed color is larger than the area of all land on Earth.
B.B. Cale of the National Oceanographic Center in Southampton (UK) and his colleagues analyzed NASA data and believe that green is a sign of ecosystems changing due to climate change.
What these changes are and what their exact cause is has not yet been established, but, according to B.B. Keila, they are most likely related to the creatures at the base of most food chains – phytoplankton. These organisms also play an important role in producing most of the oxygen we breathe and stabilizing our atmosphere. “The effects of climate change are already being felt in the ecosystem of marine micro-organisms,” the study notes.
Changes in the color of the oceans may indicate a bigger problem
According to the authors of the study, the change in the color of the ocean may reflect changes in the state of its ecosystems. Deep blues indicate declining living standards, while greener hues indicate increased phytoplankton activity. This gives an idea of what is happening in the surface layers of the water.
However, the color of the ocean can change from year to year, because the level of chlorophyll on the surface of the water varies widely. This makes it difficult to determine if climate change is affecting the blue-to-green transition.
Scientists believe it could take up to 40 years of ocean color observations before they notice any trends. In addition, different satellites measure color changes differently. This means that data from each of them often cannot be combined.
NASA’s Pace spacecraft is scheduled to launch in January 2024 to study ocean color changes in more depth. It will observe plankton, aerosols, clouds and the ocean ecosystem.