Not Only Is The Ocean Warming Faster, It Also is Experiencing An Accelerated Rise
By: Len Rosen
Tags: Climate Change, Oceans

January 14, 2019 — It appears you can only do so much to the natural environment before it comes back and bites you in the derriere. Two new studies, one led by Simon Fraser University in Burnaby, British Columbia, and comments made last weekend on an American new program by an eminent professor from Princeton’s Environmental Institute, in New Jersey, point to overwhelming evidence that world oceans are rising at an accelerating rate. At the same time, the oceans are heating up as much as 40% faster based on research done at numerous universities across the United States and the UK.

Seas Are Rising Faster as the 21st Century Unfolds

The data collected in the Simon Fraser study covers 2,000 years in the Indian Ocean. The researchers reconstructed sea levels going back that far to create a preindustrial context as a comparison to more recent observable data. And although records of sea level in the Indian Ocean from 2,000 years ago are few and far between, there is evidence from the Maldives that show historic sea levels. States Professor Paul Kench, Dean of Science at Simon Fraser, “We know that certain types of fossil corals act as important recorders of past sea levels. By measuring the ages and the depths of these fossil corals, we are identifying that there have been periods several hundred years ago that the sea level has been much lower than we thought in parts of the Indian Ocean.”

The study, published on December 16, 2019, in Nature Geoscience, concludes that the last two centuries have seen the central Indian Ocean around the Maldives rise by nearly one meter. The threat lies in the rate of sea-level rise over the last two hundred years which suggests an accelerating trend posing a threat to coastal cities and human habitation around the Indian Ocean. The rate of acceleration and sea-level rise will exceed anything in recorded history.

Last Sunday, on the American television news magazine show, 60 Minutes, Michael Oppenheimer, Professor of Geosciences and International Affairs at the Princeton Environmental Institute, stated that “Sea level is rising almost everywhere on Earth…Not only is sea level rising, the rise is accelerating — it’s happening faster and faster…By the year 2050, which is only 30 years into the future, many places around the world, including in the U.S., are going to experience the ‘historical,’ ‘once-in-a-hundred-year’ flood level once a year or more frequently. Let me repeat that: An event that used to cause severe flooding once a century, we’re going to get that same water level once a year.” Oppenheimer describes Venice as the canary in the coal mine for ocean sea level rise. The city recently experienced unprecedented inundation from the Adriatic Sea, a phenomenon that is likely to become more frequent in the coming decades.

Oppenheimer and colleagues in universities across the world are working on national migration policy related to mitigating negative impacts from sea-level rise on coastal communities. The problem in the United States states David Wrathall, in the College of Earth, Ocean, and Atmospheric Sciences, at Oregon State University, is “right now, people are actually moving toward coastlines that will be more and more vulnerable as the planet warms…The only thing that will change this trend is policy. If we start changing the incentives to live, work and invest in safer places, we could make sea-level rise-induced migration less expensive and disruptive down the line.”

The significance of the most recent studies is the trend to accelerating sea-level rise rather than a steady increase. NASA and ESA satellite altimetric data confirm this and believe the melting of ice sheets in Greenland and Antarctica are key contributors. Current rates of acceleration, not taking into consideration ocean volume increase from heat expansion (see below ), point to projections of sea levels 65 centimeters (26 inches) higher by 2100. This estimate is described as conservative.

So how much have the oceans risen over the last 25 years? The number states NASA is 7 centimeters (2.8 inches). That doesn’t sound like a lot but equates to billions of tons more of water inundating shorelines than in the past during high tides and storm surges.

Oceans are Warming Faster Than Previously Calculated

Now add warming of the global ocean to the equation. States climate scientist, Zeke Hausfather, UC Berkeley, “the ocean, in many ways, is the best thermometer we have for the planet.” Multiple studies point to an ocean heating 40% faster than any previous estimates that appear in the Intergovernmental Panel on Climate Change annual reports. In four independent studies, they all point to human carbon emissions as being responsible for this phenomenon. The consequences of accelerated warming include:

global ocean expansion contributing to sea-level rise (that’s because warm water has more volume than cold water)

damage to ocean ecosystems including coral bleaching, species migration

changes to ocean circulation (the slowing of ocean currents with potential impacts on the climate of both coastal and inland human populations)

A study published in January of last year in the Proceedings of the National Academy of Sciences (PNAS) noted that the oceans are the world’s largest heat and carbon sink and have taken up to 90% of the additional heat produced from increasing levels of greenhouse gases in the atmosphere. This study noted that ocean heating coincides with the rise of the Industrial Revolution and affects mid-latitude areas of the Atlantic Ocean more than anywhere else.

There are unknown ramifications in this warming for Atlantic circulation, in particular, the Gulf Stream and North Atlantic Drift which warm the climate of the American eastern seaboard and much of Europe. The evidence of the warming and thermal expansion can be seen all along the U.S. east coast (see the image below) contributing to rising seas, increased coastal flooding, and more frequent extreme weather.