It is terribly concerning, these worsening numbers. Hopefully we will develop the clean, unlimited power of fusion and use it to capture CO2 before it's too late. But I think we will make major breakthroughs in the next 10 to 20 years that will make the progress of the previous 20 years seem slow...

Unfortunately for this study, our oceans are an awful lot deeper than 30M so just add it to the 'hysterical scare tactics' pile along with the latest IPCC report.
I mean, no one would mind but not one single catastrophic prediction made by the alarmists has come to pass in the last 40 years, but they still keep pumping them out.

If oceans have been warming then polar ice would be melting and sea levels would have gone up by now. I have lived 50 metres away from the Pacific Ocean shoreline for 40 years. There has been no change in the tide marks or sea level of the Pacific Ocean. That is actual proof that anyone can see. Computer programmes that predict what might happen to the climate just spit out whatever has been put into them and have been proven wrong over and over.

Despite the claims here, the study doesn't claim to have found warmer current-ocean temps; it claims to have found cooler ancient-ocean temps. I think the study proves that you can get a grant for your study just by promising the abstract will read "be afraid!" And, OF COURSE, this means you will be looking to be "saved" by the tried and true method of giving money and power to politicians.

Bad Science Talking about 30 m when a lot of the ocean is 6K to 10K deep is not really relevant. As one knows the density of water is highest at 4 C, otherwise we would be in real problems, and why Ice Floats. However we should be cautious of Ice Melting, diluting the gulf stream which is cyclical and leads to an Ice Age, mini or minor.

The additional heating means additional sea level rise (because water expands with increasing temperature. With an average ocean depth of 3000 meters, that effect is about two feet per degree celsius of warming. So this could be the difference between some seawalls holding barely vs being overtopped.
It also means there's that much more effect on the various conveyor systems that power oceanic circulation. If we disrupt those, the habitability of the earth could become quite different.

There is usually something missing from the discussion of the consequence of warming ocean temperature: the coefficient of thermal expansion of water. Do the math: an average (over-simplified, but adequate for demonstration purposes) increase of the temperature of the world's ocean's of a mere 1 degree Celsius would raise sea level on the order of 9 meters/28 feet.

30 meters is a bit too shallow that's only about 0.1% of its actual depth. Besides, I'm a firm believer that this is purely a cycle of nature. Warm water leads to increased evaporation. Increased evaporation leads to more clouds. More clouds lead to increased precipitation and cooler temps. Cooler temps with more precip. leads to increasing ice sheets and snow which leads to ...

"The working principle behind the study is that as water warms up, it releases more oxygen and carbon dioxide into the atmosphere."
Really...
What happened to "Ocean Acidification" then?
As to a study that starts by assuming the oceans are 30M deep and extrapolating from there...
Don't bother!

OhMyGodWe'reGonnaDie...Again...EvenQuicker! Ayieeeeeeeeeeeeeee!
Buy your new Arizona beachfront lots NOW, folks! Wow, FL and CA gone. L.A.,NYC, Manhattan, and NOLA underwater.
Possible map. Oh, dear. http://www.pnas.org/content/106/51/21461
P.S: That bull puckey is only if you believe the Alarmists. If not, no worries. Humans adapt to things =if= and when they happen. No big.