Friday July 14, 2023
Scientific American —
Climate change is reshaping the surface of the Earth — even down to the color of the oceans.
A new study says that more than half the world’s ocean area is “becoming greener,” and the trend is connected to human-caused global warming.
It’s not clear what is driving the greening. In some places, it could indicate changes in the amount of plankton or other organic material floating in the water. Plankton are a cornerstone of the ocean food chain, and these kinds of shifts could have ripple effects throughout the entire marine ecosystem.
That’s a topic for future research. For now, the researchers can say for sure that the oceans are changing colors, and climate change is to blame.
The study, published Wednesday in the journal Nature, examines 20 years of satellite data measuring light reflected at the surface of the water all across the globe, subtle changes that aren’t necessarily visible to the naked eye. The research finds that 56 percent of the world’s oceans are shifting in color — and on the whole, they’re growing greener. The trend is especially strong in the lower latitudes, including the subtropics and tropics.