Green and blue ocean colors may intensify as temperatures rise

A new study warns that the blue and green colors presented by the world's oceans will intensify as Earth heats up. This transition will be caused by shifts in phytoplankton populations, which are experiencing major changes driven by climate change. According to the study, these color changes may impact more than half of the planet's oceans by the year 2100.

The findings were revealed in a study published in Nature Communications, where researchers describe a global model simulating phytoplankton (algae) transitions in different parts of the world. Algae influences the light absorbed and reflected by the oceans, impacting the green and blue hues were see in different regions.

When a part of the ocean has a high phytoplankton population, the color we see skews toward the green side of the spectrum. In regions with less phytoplankton, the colors appear bluer. These small organisms require nutrients, sunlight, and carbon dioxide to thrive, resulting in differing populations and what appears to be some ocean regions that are more blue than others.

Climate change, however, is altering phytoplankton populations around the world. Warmer temperatures have enabled phytoplankton to bloom in larger quantities in some parts of the world, while other regions have experienced a decrease in algae. According to the study's model, the next several decades could see some bluer parts of the ocean appearing even more blue, while other greener ocean regions may turn a deeper green color.

This shift in hues won't be huge to the naked eye, however the study warns that the change in phytoplankton will have a sprawling effect on the food webs the organisms support. The model was based on a global temperature increase up to 3 degree Celsius, which is the anticipated increase if humanity doesn't take big steps to address greenhouse gases.