The color of the world’s oceans is undergoing a transformation as a result of climate change, suggests an analysis of Nasa images. Research indicates that the increase in green hues observed in the sea is linked to alterations in plankton populations. Notably, regions located in the low latitudes near the equator appear to be particularly impacted by these changes.
According to a team of researchers, over 56% of the world’s oceans have experienced a color change that cannot be attributed to natural variability.
MIT and the UK’s National Oceanography Center conducted a study that examined two decades of data collected by the Aqua satellite and its MODIS sensor. This sensor measures the color of Earth’s oceans. The study revealed notable changes in ocean color during the past 20 years. These changes cannot be solely explained by natural year-to-year variations. This suggests that there are other factors at play, potentially related to human-induced climate change.
The color of the ocean is intricately connected to the composition of its upper layers.
Sunlight that reaches the ocean is absorbed, leading to the filtration of red light from the spectrum. However, when these upper layers contain organic matter such as phytoplankton, the light reflects off them, resulting in a greener color.
The study’s findings indicate that measuring ocean colors can help detect the effects of climate change on marine ecosystems. This approach also provides scientists with a faster and more sensitive method of assessment.
“The color of our oceans has changed,” said Dutkiewicz. “And we can’t say how. But we can say that changes in color reflect changes in plankton communities, that will impact everything that feeds on plankton. It will also change how much the ocean will take up carbon, because different types of plankton have different abilities to do that. So, we hope people take this seriously. It’s not only model that are predicting these changes will happen. We can now see it happening, and the ocean is changing.”
The researchers stress the importance of additional research that combines data from multiple satellites. This collaborative effort would contribute to a better understanding of the implications derived from the observed trends in their study. Ultimately, it would provide a comprehensive comprehension of the changes unfolding in the ecology of surface-oceans.
The study’s findings were published in the scientific journal Nature.
