A recent CU Boulder study describes how the waters surrounding the Galápagos Islands are both remaining cool and becoming colder while the majority of the world’s oceans are warming as a result of climate change. The study, which was published in PLOS Climate, demonstrates that the Galápagos Islands are protected from an otherwise warming Pacific Ocean by a cold ocean current, eastward equatorial ocean current and that this current has been gaining strength over time. In actuality, since the early 1990s, the waters off the west coast of the Galápagos have cooled by 0.9 degrees Fahrenheit (0.5 degrees Celsius).
“Our greenhouse effect,” which warms the earth from above, is at odds with the chilly ocean current. The ocean current is currently in control; the temperature is not just remaining cool but decreasing yearly. ” In accordance with Kris Karnauskas, the study’s lead author and an associate professor in the department of atmospheric and oceanic sciences as well as a fellow at the Cooperative Institute for Research in Environmental Sciences (CIRES),
The second-largest marine reserve in the world, a biodiverse island ecosystem that is home to several endangered species and is listed as a UNESCO World Heritage Site, should be cautiously optimistic in light of this event.
The flora and fauna of the Galápagos could help reseed failing ecosystems and maintain the region’s fisheries if corals don’t bleach and die in these waters off the western coast of Ecuador and the marine food chain doesn’t struggle as it will in neighboring warmer waters.
“Galapagos could be considered as a prospective site to really try to put some climate change mitigation efforts into practice,” said Karnauskas. “The Galápagos has been largely unscathed by climate change up to this point.”
The waters off the west coast of the Galápagos are certainly in need of greater protection from overfishing as well as the pressures of growing ecotourism, though, as one of the few places left in the world’s oceans that are not now warming.
According to Karnauskas, “the human pressures on this area and the system that sustains it are at odds.” “It’s a significant resource that has to be preserved.”
An accident of geology
From orbit, the Galápagos Archipelago may appear to be a collection of minuscule specks in the eastern Pacific Ocean. However, it is their precise position on the equator that gives them such importance.
This equatorial undercurrent in the Pacific Ocean is bound to the equator by the force of the planet’s rotation since the Earth rotates on an axis. Under the ocean’s surface, a swift circulation of cold, nutrient-rich water flows from west to east. Some of this water is forced to the surface when it reaches the Galápagos Islands, where the chemical reaction of photosynthesis leads to an explosion of food for a wide variety of animals.
Therefore, despite the fact that the islands are in the tropics, the cold ocean current that encounters them creates a cooler, more stable environment for coral reefs, as well as for marine life and birds that ordinarily reside considerably closer to the poles. The UNESCO World Heritage Convention calls these islands a “living museum and exhibition of evolution.” The Galápagos penguin, the Galápagos fur seal, and the Galápagos sea lion are all endangered species that live on these islands.
Karnauskas and co-author Donata Giglio of the Department of Atmospheric and Oceanic Sciences at the University of Colorado Boulder used data from thousands of floating ocean sensors put in place since 2000 to confirm that this Pacific equatorial undercurrent is the cause of the cold water that rises from below to surround and support the islands’ thriving ecosystem. This paper was published in August of this year in Geophysical Research Letters.
Rising cold current
When working at the Woods Hole Oceanographic Institution a decade ago, Karnauskas utilized other data to demonstrate how cold ocean current can shield some islands or coastlines from the damaging warming consequences of climate change. This most recent study shows that the Galápagos Islands are real and that the cold current is getting stronger.
According to Karnauskas, “there is clear evidence that shows that this current has been intensifying and the cold water on the western sides of the islands has been getting colder all the way back to 1982.”
But why is the current in the frigid ocean becoming stronger?
This current is already one of the strongest in the entire world and it originates close to Australia. Using a freshly created high-resolution ocean model, Karnauskas came to the conclusion that the reason for the planet’s ongoing cooling is due to changes in the winds that blow across the equator.
Karnauskas says that even though the equatorial undercurrent is getting stronger, it is still not clear if this is because of human-caused climate change or if it is just a natural cycle.
Are the Galapagos Islands perpetually safe? Not exactly, replies Karnauskas.
Every two years, El Nio, which is the warm phase of a recurrent climate pattern in the tropical Pacific, offers a short-term hazard by blocking the cold current, which causes penguin numbers to collapse. Even though El Nio happens without the cold current, it gives us a hint of what might occur if it didn’t.
The environment could suffer greatly if there were alterations to this current in the future, according to Karnauskas.
According to Karnauskas, this refuge from climate change might not last if the waters keep warming at the same rate they have been.
It’s hanging on so far, as the numbers clearly demonstrate, according to Karnauskas. It doesn’t mean that it will last indefinitely, she said.
