A new study says most of Earth’s oceans have changed color over the past 20 years, and this is suspected to be due to human activity. This dark blue color, which is often seen on postcards, is lost, especially in the tropics.

“Overall, oceans at low latitudes have become greener in the last 20 years,” the report says. Nature.

This discovery confirmed what the study’s co-author Stephanie Dutkiewicz had long feared.

“For years I’ve run simulations that tell me these ocean color changes are going to happen,” he said in a news release at MIT. “It’s not surprising but scary to see how that actually happens. And these changes are consistent with human-induced climate change.”

The color change was discovered during the researchers’ processing of two decades of satellite data. They eventually concluded that 56% of the ocean’s surface is greener than it was before the turn of the century.

The team concluded that the color change would affect “marine food webs.” But the report does not point to a broader human impact. Scientists suspect that these changes may be caused by climate change. However, the study concluded that this trend does not appear to be associated with increasing sea surface temperatures.

“We don’t know what’s causing this trend. There could be changes in dissolved organic material, the type and amount of phytoplankton … all these aspects can affect the color of the ocean,” study co-author Emmanuel Boss told EOS Science News.

“We hope more of our colleagues will try to find out the reason for these changes.” Source