Oceans are Warming Even Faster than Previous Estimates

Oceans are Warming Even Faster than Previous Estimates

Oceans are Warming Even Faster than Previous Estimates Absolute Knowledge
Oceans are Warming Even Faster than Previous Estimates

Four different studies reveal that greenhouse gases are raising temperatures of oceans at a much rapid rate than previously believed.

Ocean Heating is a critical marker of climate change because most of the excessive solar energy absorbed by the greenhouse gases is accumulated in oceans. In addition to that, ocean temperatures don’t experience year-to-year variations caused by extreme climatic events like Volcanic Eruptions and El Nino. According to a recent report, trends in ocean heat content coincide with the estimations made in the leading climate change models, which claim that overall ocean warming is accelerating. This result is another piece of evidence which suggests that the theory of ‘Hiatus’ in global warming is not true. Zeke Hausfather, a Co-author of the paper who is a Graduate Student at the University of California, referred to that by saying,

“If you want to see where global warming is happening, look in our oceans. Ocean heating is a very important indicator of climate change, and we have robust evidence that it is warming more rapidly than we thought.”

The Coupled Model Intercomparison Project 5 (CMIP5) models of climate change predict that the temperature of the top 2,000 meters of the oceans of the world will approximately rise by 0.78o C by the end of this century if we continue to pollute our atmosphere with greenhouse gases at the current rate. Consequently, the sea levels will rise around 12 inches due to thermal expansion of the ocean water. This will create a lot of catastrophes because the melting of ice sheets and glaciers is already causing some significant rise in sea level. Similarly, a warmer ocean will produce hurricanes, stronger storms, and extreme precipitation. Hausfather commented on that in the following words:

“While 2018 will be the fourth warmest year on record on the surface, it will most certainly be the warmest year on record in the oceans, as was 2017 and 2016 before that. The global warming signal is a lot easier to detect if it is changing in the oceans than on the surface.”

Nearly 4,000 floating robots are scattered in all the oceans of the world. Every few days, they dive to a depth of 2,000 meters to measure the pH, salinity, temperature, and other vital factors of the ocean. The name given to this ocean-monitoring fleet is Argo, which has been providing consistent data on ocean heat content since the mid-2000s. Prior to that, Expendable Bathythermographs were used to collect data for ocean temperatures. The problem with that method was that these bathythermographs provided information on ocean temperature only before settling into watery graves. As a result, the data was not that accurate.

Three of the studies included in this latest analysis used advanced techniques to correct calibration errors and biases in the data gathered by both the methods (Bathythermograph and Argo). On the other hand, the fourth study based its calculations for ocean warming on the atmospheric concentrations of Oxygen. They used the fact that a warming ocean releases Oxygen to the atmosphere. Having said that, they also took into account other factors, like oxidation of fossil fuels, which affect the Oxygen levels of the atmosphere. Hausfather tried to explain the importance of these four records and said,

“These four new records that have been published in recent years seem to fix a lot of problems that were plaguing the old records, and now they seem to agree quite well with what the climate models have produced.”

All these studies corrected the discrepancies in different types of ocean temperature measurements which allows them to provide a better estimate of past trends in ocean heat content. Likewise, they accounted for gaps in measurement over location or time to ensure that the results are as accurate as possible. This correction of records has eliminated a massive uncertainty that was circling in the scientific community for quite some time now. Hausfather acknowledged that by saying,

“The Intergovernmental Panel on Climate Change’s (IPCC) Fifth Assessment Report, published in 2013, showed that leading climate change models seemed to predict a much faster increase in ocean heat content over the last 30 years than was seen in observations. That was a problem, because of all things, that is one thing we really hope the models will get right. The fact that these corrected records now do agree with climate models is encouraging in that it removes an area of big uncertainty that we previously had.”         

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