Our Blue Planet Is Going Green.

Planet Earth, known as the "Blue planet“, is undergoing significant changes due to climate change and this is increasingly evident in aquatic ecosystems. Recent studies address different aspects of these changes.

One such study, published in Geophysical Research Letters, revealed a worrying scenario about the future of our planet, indicating that the color of the waters of the Blue Planet are changing color.

Another study published in the journal Nature Sustainability, was based on the analysis of satellite images captured over 20 years and corroborated that study, concluding that the Earth's oceans are changing color and becoming greener because of climate change.

These studies reinforce the urgent need for action to mitigate climate change that is having serious implications for all aquatic ecosystems and protect them as soon as possible, before it's too late.

Goodbye, Blue Planet

It is no coincidence that Earth is known as the Blue Planet. About 71% of our planet's surface is covered in water, giving it that distinctive blue color that stands out amidst the red of Mars and the brownish yellow of Jupiter.

However, a radical change is taking place. A new study published in Geophysical Research Letters presents a bleak scenario for the future of our planet due to climate change, and one of the predicted consequences is the change in the color of the waters of our Blue Planet to green.

A study recently published in the journal Nature Sustainability used satellite imagery over two decades to analyze color changes in the oceans. The results revealed that, due to climate change, the Earth's oceans are undergoing a radical transformation, becoming increasingly green. This change is especially noticeable in the equatorial region.

The increase in temperature in the oceans is leading to the proliferation of various species of algae, and increasing the amount of phytoplankton, which is making water bodies, from rivers, lakes to oceans, greener, making our Planet Blue in Planet Green.

Green Lakes

Rising global temperatures are changing the blue lakes, which are now turning a darker, brownish-green hue. The color of lakes is determined by several factors, mainly the amount of algae and sediment present. Air temperature, precipitation, depth and elevation of a lake also influence the hue of its waters.

Blue lakes are the majority on the planet and tend to be deep and found in colder regions with higher latitudes and higher precipitation. Green and brown lakes are more common in drier areas, in the continental interior and along coasts, as reported by IFLScience.

This research analyzed more than five million satellite images related to 85.360 lakes and reservoirs around the world between 2013 and 2020, comparing changes in color. The team created an interactive map that displays the results of these images.

With rising temperatures and a drier climate, blue lakes are becoming increasingly rare due to algal blooms, giving them a greener hue.

"Nobody wants to swim in a green lake."

"So, aesthetically, some lakes that we've always seen as refuges or spiritual places are going to start to fade with the color change."

Catherine O'Reilly, an aquatic ecologist and study author, explained.

However, the cosmetic changes are the least of the problems. The color change is a sign that these ecosystems are undergoing drastic changes, affecting the flora and fauna that depend on these lakes.

"There may be periods when the water is unhealthy and the fish species may no longer be present."

“So we are not going to have the same service as the ecosystems of these lakes when they change from blue to green”, he concluded.

Color Change in the Waters

This color change is due to rising water temperatures, which results in growth in populations of phytoplankton – small microorganisms, such as algae, that use green chlorophyll to carry out photosynthesis. The more phytoplankton there are, the greener the oceans become.

The color change is far from the only impact. The increase in phytoplankton eventually reduces the amount of oxygen in the water, creating more dead zones where only a few species can survive.

The researchers say phytoplankton may not be the only reason the oceans are changing color, but their analysis is in line with an advanced model that predicts how ocean ecosystems may be responding to climate change.

Although the increase in phytoplankton numbers can be seen as a valuable carbon sink, as they absorb CO2, the situation is more complex than it first appears, as explained by Science Alert.

These microorganisms have the ability to significantly alter their environment, including temperature, nutrient availability and light levels in the water. Furthermore, they are the base of the marine food chain. Therefore, its increase is likely to cause widespread changes in the conservation of certain areas and in the fishing industry.

These changes in the oceans have important implications for marine ecosystems and for life on Earth as a whole. It is crucial to take action to mitigate climate change and preserve the health of the oceans, thus ensuring a sustainable future for our Blue Planet.

A Deafening Noise

Unfortunately climate change is not only having an impact on the color of the waters. A study published in Earth's Future, concluded that due to the warming of the waters, sound waves are propagating faster and are longer lasting, making the oceans more “noisy”, which will have implications for the communication of marine animals.

"We calculate the effects of temperature, depth and salinity based on public data to model the soundscape of the future."

Revealed Alice Affati, researcher of bioacoustics and lead author of the study. This is the first study to address the impact of climate change on ocean sound.

The research predicts that two specific points will undergo significant changes at depths of 50 meters and 500 meters, one in the Greenland Sea and the other in the northwest Atlantic Ocean.

The average speed of sound is expected to increase by more than 1,5%, approximately 25 meters per second, from the surface to a depth of 500 meters by the end of the century, if greenhouse gas emissions continue to increase.

The soundscape of the oceans includes vibrations produced by living organisms, natural phenomena such as crashing waves or cracking ice, and also sounds caused by human activity such as maritime trade or the extraction of natural resources.

Impact for Whales and Dolphins

Many marine animals, such as whales or dolphins, use sound to communicate with each other. Therefore, changes in the speed of sound due to warming waters affect these animals' abilities to feed, find mates, migrate or escape predators.

In addition to the two points mentioned as being most vulnerable, the study also concluded that there will be a 1% increase in the speed of sound at 50 meters of depth in the Barents Sea, in the northwest and south Pacific, and at 500 meters in the Arctic Ocean, in the Gulf of Mexico and the southern Caribbean Sea.

The researchers also modeled the common vocalizations of the North Atlantic Right Whale, an endangered species, within the future projections. It was concluded that the typical call of these animals, which occurs at 50 Hertz, will propagate more in a warmer ocean.

In the future, the team intends to create a map that assesses the intersection of several factors that influence the soundscape of the sea and identifies the most affected areas.

Conclusion

These recent studies reveal the diverse consequences of climate change on aquatic ecosystems. From the change in color of lakes and oceans, which reflects changes in the amount of algae and sediments, to the increase in noise in the waters, which seriously impairs the communication of marine animals, the effects are worrying.

Climate change is not a “Myth” it is really happening and it is becoming more and more evident. It is essential to act in favor of the preservation of ecosystems and adopt measures to reduce climate change, or else we will not have a planet where we can survive.

What do you think of these climate studies? Does this change from “Blue Planet” to “Green Planet” bother you? We want to know your opinion, do not hesitate to comment and if you liked the article, share and give a “like/like”.

See also:

The world may enter a circle of destruction

Climate: Have we passed the point of no return?

Africa: Nuclear Power. Clean, Green, Reliable

The extreme weather of World Weather Day

Picture: © 2023 Francisco Lopes-Santos