Bell-bottom jeans, Abba, and the Labrador Current — one of the three is not making a retro comeback. Temperature-tracking coral reefs indicate that the circulation of water in the Atlantic Ocean has changed dramatically since the 1970′s.
That could be part of the reason areas in the northern hemisphere have had harsh winter storms and summer droughts say researchers.
The evidence for changing currents comes from ancient gorgonian coral reefs growing off the coast of Nova Scotia. The reef was studied by a team of biochemists and oceanographers from Switzerland, Canada, and the United States.
Like most organisms, corals are what they eat and changes in their diet are recorded in the reef structure.
The Canadian corals showed that the cold, south-bound Labrador current is losing ground to the warm, north-bound Gulf Stream current. The corals of the deep north Atlantic have been feasting on nutrient-rich warm water since the 1970′s.
The researchers looked at the concentrations of a certain isotope of nitrogen, called delta 15. Different concentrations of the isotope allow scientists to trace a creature’s food sources.
The levels the researchers found in the Nova Scotian coral indicated the coral had been feeding heavily on nutrients brought north from the subtropical regions for approximately 40 years.
The coral had been feeding primarily on subarctic nutrients for the previous 1800 years.
That abrupt change in food sources caused by changes in currents coincides closely with the onset of observable changes in Earth’s climate caused by industrialization.
“The researchers suspect there is a direct connection between the changes in oceanic currents in the North Atlantic and global warming caused by human activities,” said one of the participating institutions, the Swiss Federal Institute of Aquatic Sciences and Technology in a statement to the Associated Foreign Press.
The coral reef research was published recently in the Proceedings of the National Academy of Sciences.
Recent heavy snowfalls and harsh winter storms along with droughts and heat waves in the summer, could be explained by a changes in the circulation of the Atlantic’s water, say climate researchers. A 2004 paper by NASA explained the possibility of melting arctic sea ice triggering colder weather in Europe and North America.
As my colleague, Mr. Cox, pointed out in the above blog post, the term global warming is a misnomer in many senses. Humanity faces global climate destabilization. The weather patterns our agriculture and industry have adapted to over the centuries are changing rapidly.
In his book Collapse, Jared Diamond, points out many examples of civilizations failing to adapt to climatic changes. Weather changes in the north contributed heavily to the demise of the Vikings in Greenland, for example.
Other examples of civilizations crumbling under environmental pressures comes from 535 AD, as detailed by David Keys in Catastrophe: A Quest for the Origins of the Modern World. Civilizations from Mexico to Java to the Byzantine empire show evidence of a serious crisis at that time. An event, possibly a massive volcanic eruption, caused a world-wide reduction in temperature and darkening of the skies. Crops failed and famine followed.
History shows us that fluctuations in the climate can have serious effects on humans and the Earth’s ecosystems. But the Earth has recovered from numerous calamities in the past.
The real danger from climate change, biodiversity loss, deforestation, ocean acidification, and other phenomenon is to the stability for global human civilization.
The Earth will be fine. It’s humanity that needs to better plan for its future.