STONY BROOK (US) — Locally, changes in coastal ocean temperatures may be much more extreme than global averages imply.
By looking at changes over the past 30 years, researchers have mapped the differences in how the world’s coastlines are experiencing climate change to learn what the possible large scale ecological implications will be.
Their results show a great regional diversity in warming and cooling patterns. For example, the South American Pacific coasts have been cooling over the last few decades.
These cooling trends may be counterintuitive, but are consistent with global climate change predictions, such as increases in upwelling (i.e., a process that brings cold, deep ocean water to the coast).
“The world is getting flatter,” says Hannes Baumann. (Credit: Stony Brook)
In the North Pacific and North Atlantic, however, there has been warming trend. In some areas, the authors detected changes in temperature of +/-2.5 degrees Celsius, which is 3 times higher than the global average.
“Climate change is happening everywhere—just not necessarily at the same rate, or even in the same direction,” the researchers say in the study, published in PLOS ONE.
For example, if you live on Cape Cod, your conditions are warming three times faster than global averages imply, while in Santiago, Chile, coastal waters have been getting cooler.
“The world is getting flatter,” says Hannes Baumann from the School of Marine and Atmospheric Sciences at Stony Brook University.
“Coastal waters at high (cold) latitudes warm much faster than at low (warm) latitudes, hence the majority of the world’s coastal temperature gradients are getting shallower. This could cause dramatic reorganization of organisms and ecosystems, from small plankton communities to larger fish populations.
“We already know, in general, that marine life changes in its characteristics along these North-South temperature gradients,” Baumann says. “For example, many coastal fish populations differ genetically from north to south, an adaptation to grow best a local temperature conditions.
“With further study, we want to explore how changes in coastal ocean temperature gradients could predict large-scale changes in the ecosystem.”
Source: Stony Brook University