These are too small for humans to see and will appear largely blue to the naked eye. (Representative)
Paris:
Large swaths of the world’s oceans have changed color over the past 20 years, showing slight greening in the tropics, which researchers say points to the effects of climate change on life in the world’s oceans.
In new research published on Wednesday, scientists say they have detected changes in color across more than half of the world’s oceans – a larger area than Earth’s total land area.
The authors of the study in Nature believe this is due to changes in ecosystems, and particularly in small plankton, which are the centerpiece of the marine food web and play a key role in stabilizing our atmosphere.
“We care about color change because color reflects the state of an ecosystem, so a color change means a change in the ecosystem,” lead author Bibi Kail from Britain’s National Oceanography Center told AFP.
Seen from space, the color of the ocean can offer a picture of what is happening in the upper layers of the water.
A dark blue color will tell you there isn’t much life in it, whereas if the water is green it’s likely to have more activity, especially from photosynthetic phytoplankton, which contain the green pigment chlorophyll like in plants.
They produce a significant amount of the oxygen we breathe, are an important part of the global carbon cycle and are a fundamental part of the marine food web.
– color of life –
Researchers are keen to develop ways to monitor changes in ecosystems to track climate change and secure protected areas.
But previous studies have shown that you would need three decades of marine chlorophyll monitoring to detect a trend due to annual variations.
In the latest study, the researchers expanded the color spectrum, looking at seven shades of ocean color monitored by the MODIS-Aqua satellite from 2002 to 2022.
These are too small for humans to see and will appear largely blue to the naked eye.
The authors analyzed the observational data to find a trend above the year-to-year variability and then compared it with what computer models expected with climate change.
They found that the real-world observations matched the predicted changes quite well.
While the researchers said more work would be needed to figure out what exactly those color changes might mean, they said climate change is very likely to be the cause.
“I’ve been running simulations for years that tell me these changes in ocean color are going to happen,” said study co-author Stephanie Dutkiewicz of MIT’s Department of Earth, Atmospheric and Planetary Sciences at the Center for Global Change Science. ,
“To see this actually happening is not only surprising, but frightening. And these changes are consistent with human-induced changes in our climate.”
(Except for the headline, this story has not been edited by NDTV Staff and is published from a syndicated feed.)