Ocean Warming

[transreality]

A large simple unit of heat that humans seem to understand is 'hiroshima atomic bomb' equivalents. If you could express the global warming of the oceans in terms of a rate of underwater atomic bomb explosion equivalents, I suspect people would get the idea.

actually, I found this one: more than 2 hiroshima bombs per second!

[Ara Pacis]

A large simple unit of heat that humans seem to understand is 'hiroshima atomic bomb' equivalents. If you could express the global warming of the oceans in terms of a rate of underwater atomic bomb explosion equivalents, I suspect people would get the idea.

actually, I found this one: more than 2 hiroshima bombs per second!

On the contrary, most people drastically over-estimate the power of nuclear weapons.

[HenrikOlsen]

At present it sounds alarming, but as soon as the listener realises that this rise has occurred over 50 years and has only raised the average temperature by one tenth of one degree, they will see no urgency to the matter. They may even start to think that the whole problem has been inflated. That would be bad for all of us. The naysayers may be wrong but in the end we need to convince them.

This is a nice example of why talking about the temperature change of the ocean is a bad idea.
Exactly because it's a system with phase changes, temperature is a meaningless measure of heat flow so denialists can use the stability of the temperature to claim nothing much is happening.

Volume of ice melted at the caps is the measure of the increased heat flow, not ocean temperature nor extent of sea ice coverage (another denialist false indicator since it's a thin layer that's part of the annual cycle rather than an indicator of volume of ice present).

[Robert Tulip]

because it's a system with phase changes, temperature is a meaningless measure of heat flow so denialists can use the stability of the temperature to claim nothing much is happening.

But the ocean temperature is not stable. The total heat energy increase measured in the top two kilometres of the sea since 1969 is 2.3 x 10²³ joules, with a very clear upward trend.

How are phase changes relevant except at the margin? This source says about 97% of all water on earth is in our oceans, 2% is frozen in ice caps and glaciers, and less than 0.3% is in the atmosphere ?

http://en.wikipedia.org/wiki/Joule#Zettajoule says "The zettajoule (ZJ) is equal to 10²¹ joules. Annual global energy consumption is approximately 0.5 ZJ". That means the energy increase in the sea over the last 43 years is 200 times annual energy consumption, meaning ocean energy level is increasing at five times the amount of world energy use. Have I got this right?

Denialists might imagine the ocean can soak up our global warming impacts for ever, but that seems highly dubious.

The average ocean temperature is just 4° C, so the 0.1° increase of the top two km is 2.5% of the average temperature. Admittedly that 4° average includes the cold temperature of the deep sea, but still it looks to be a significant change in a very short geological time.

http://en.wikipedia.org/wiki/Joule#Yottajoule says "The yottajoule (YJ) is equal to 10²⁴ joules. This is approximately the amount of energy required to heat the entire volume of water on Earth by 1° Celsius."

[ShinAce]

I wish it were that simple.

First of all, 0.1 degress Celsius is not 2.5% of anything. Global sea temperature is not limited between 0 and 4 degress C. If you want to work in percentage, may I suggest Kelvin or Joules.

Secondly, without calculating the energy of fusion used to melt ice, we can't say whether or not it's a significant factor.

Thirdly, ocean currents themselves are huge players. A shift in the circumpolar current could cause serious upwelling and changing the measurement, since we only check the top two kilometres.

Lastly, how do we even differentiate the active heating caused by things we do now, versus the latent heating caused by emissions of the past? Even if we did everything right with zero emissions, does that mean the earth will start cooling again tomorrow? Or should we continue to heat up the earth? Maybe we can reverse the expanding deserts and make more habitable land. I want hippos in the Thames again!

[profloater]

something odd here: total solar energy in per year is about 5 x 10^24 Joules or 5000 ZJ or 5 YJ.
So total energy consumption is about 10000 times less than the sun's input.
The Oceans are at 277 K so, ignoring for the moment latent heat of melting ice, using the figure 1 YJ for 1 degree, the oceans store 277 YJ which is about 55 years worth of total solar radiation.
0.1 degree if it represents the whole ocean, is equivalent to 0.1 YJ or 10^23 Joules .
Or we could say it represents a fiftieth of one year's sunshine or 1/2500 of 50 years sunshine.
Now how confident are we that we can and could measure the ocean temperature to 0.1 degree? This is not a denial position, just a different perspective.

[Robert Tulip]

how confident are we that we can and could measure the ocean temperature to 0.1 degree?

Your question has prompted me to shell out my $25 and buy the Levitus et al paper World ocean heat content and thermosteric sea level change (0–2000 m), 1955–2010.

The answer, as shown in the error bars in the graph linked in the OP, is that researchers can be very confident of ability to measure the ocean temperature rise to this level of accuracy. The scientific oceanographic community has Argo profiling float data provide data to 2000m depth on a near-global basis. See information on Argo

Data used in the paper is available at http://www.nodc.noaa.gov/OC5/indprod.html

The paper includes this graph which separates out the measured heat increase by ocean and depth. It shows that most of the increase is at the surface, but there is still significant warming at deeper levels.
Ocean Heat Content Change 1955-2010 Levitus et al GRL 39.gif

[profloater]

Thanks for that; it is very interesting. I see a surface increase of 6 x 10^22. J
Some authorities say the sun output increased from 1950 at about 0.05% per decade.
That is an energy increase of 2.5 x 10^21 J per decade so over five decades about 1.2 x 10^22 Joules.
Visually integrating the graph the increase in sea stored energy is about ten times as much. Does that look right to you?

[orionjim]

...

The answer, as shown in the error bars in the graph linked in the OP, is that researchers can be very confident of ability to measure the ocean temperature rise to this level of accuracy.

...

I would suggest looking into the history of the papers by Levitus et al. They’ve written several papers on ocean warming prior to the paper released in 2012.

Then read this paper published in 2007 by Gouretski and Koltermann; it showed that the XBT and CTD measurement systems used in taking the ocean temperature data had a .2c to .4c bias. Compare that bias to the final result of the Levitus el al papers conclusion and your interpretation of it.

You can find the Gouretski and Koltermann paper here:
http://epic.awi.de/17644/1/Gou2007a.pdf

Levitus et al wrote a reply in 2009 that can be found here:
ftp://ftp.nodc.noaa.gov/pub/data.nod.../grlheat08.pdf

This reply explains what they found and how they would manipulate the data for future papers. You really need to read this paper; because I can’t believe that anyone that does would have a warm and fuzzy feeling about any results that are produced with the manipulations they’re using.

The 2012 paper uses the data manipulations they defined in the 2009 paper. And remember when looking at the error bars in their plots and think about the .2c to .4c bias (remember this is only bias and does not address precision or repeatability of the measurement system). And also think about the date the XBT bottles were manufactured influencing the bias and how they handled that. (This was defined by Wijffels et al.[2008]).

FWIW, you could have gotten their 2012 paper here for free:
ftp://ftp.nodc.noaa.gov/pub/data.nod.../grlheat12.pdf

[Ari Jokimaki]

Others are using terms such as corrections and adjustments, so why are you calling them "manipulations" with a tone that seems to suggest that there's something evil going on?

[orionjim]

Others are using terms such as corrections and adjustments, so why are you calling them "manipulations" with a tone that seems to suggest that there's something evil going on?

I typed “data manipulation” into Google and looked at the first 40 hits and found most of the hits were to SAS and other statistical sites. Not a hint of evil.

I’m a retired statistician, and my job was to manipulate data.

But to be honest Ari, there was a great deal of sarcasm in my post. You have a group of people writing a paper that was supposed to be the De Facto Standard on ocean warming and they never took the time to understand the measurement system being used. (I say this because if they did take the time and knew about the bias, then what they did was criminal.)

I also know that the problems with the data the measurement systems produced, because of the biases and variations between build dates, can only give you a vague idea of what the ocean temperatures were.

[whimsyfree]

The paper includes this graph which separates out the measured heat increase by ocean and depth. It shows that most of the increase is at the surface, but there is still significant warming at deeper levels.
Ocean Heat Content Change 1955-2010 Levitus et al GRL 39.gif

That graph makes no sense to me at all. The amount of heat at a particular depth is 0J because a depth defines a body of zero volume.

[ShinAce]

Whimsyfree: The graph shows a line connecting points, but the line isn't real. The data is binned and then the central value is marked on the graph as a point. The lines are there to help guide the eye. The answer to your non-question is that they've binned the data and that data is clearly shown as points.

Think of it like a picture. If we use your logic, then still images aren't possible because you can't gather any photons in zero time. So, we simply use exposure and call it a still. Just like how they use a depth gap and call that a depth.

[lomiller1]

Thanks for that; it is very interesting. I see a surface increase of 6 x 10^22. J
Some authorities say the sun output increased from 1950 at about 0.05% per decade.
That is an energy increase of 2.5 x 10^21 J per decade so over five decades about 1.2 x 10^22 Joules.
Visually integrating the graph the increase in sea stored energy is about ten times as much. Does that look right to you?

Ocean heat content for the top 2000m has increased by ~2.5X10^23J since 1970 (which was about the same as 1950)

http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/index.html


Such massive numbers really are hard to wrap ones head around because they are so much higher than anything that ever happens on earth. For example:
KT extinction asteroid impact - 4*10^23J
Mt Toba Super-volcano eruption 75, 000 years ago - 3*10^21J
Global electricity production - 7*10^19J
Japan's 2011 earthquake - 2*10^18J
Krakatoa eruption (1883) - 8*10^17J

Some authorities say the sun output increased from 1950 at about 0.05% per decade.

I don't know where you are getting that from but it does not look correct. Solar output has been roughly constant since 1950. From 1900 - 1950 it may have increased by as much as 1 W/m^2 (~0.07%) but you can't translate this directly into ocean heat because the ocean and atmosphere will warm as much as required in order to increase the planets outgoing infrared by that same amount or 0.25W/m^2 (remember IR is going in all directions while sunlight only comes from one). In comparison various greenhouse trap ~3W/m^2 more IR than they did in 1900. (which would be the equivalent of a 12W/m^2 increase in solar intensity)

[profloater]

thank you for that it puts it into perspective and the comparison that stands out is that the ocean heating is same order of magnitude as the KT extinction event! I remain skeptical about measurements of ocean temperature before all the sondes were in place but acidification is a big worry right now. I googled various estimates of sun output and used information from a recent meteorite survey using titanium isotopes but of course estimated historical energy balances is another modelling exercise.

[Ari Jokimaki]

Orionjim, all you have offered is your declaration of the issue without any substance. You selected one paper (Gouretski & Koltermann, 2007), pretended that it presents absolute truth and used that as a launching pad for your criminal data manipulation claims.

What you failed mention is that there are other studies on the issue by other research groups that are in agreement with Levitus et al. and in disagreement with Gouretski & Koltermann. Here are couple of recent examples:

Lyman et al. (2010), Robust warming of the global upper ocean
ftp://ftp.soest.hawaii.edu/coastal/C...ing%202010.pdf
Uses different XBT correction methods to arrive to similar results as Levitus et al.

Hamon et al. (2012), Empirical correction of XBT data
http://www.coriolis.eu.org/content/d...1.05082011.pdf

But these are probably also just doing the criminal data manipulation, right?

[orionjim]

Orionjim, all you have offered is your declaration of the issue without any substance. You selected one paper (Gouretski & Koltermann, 2007), pretended that it presents absolute truth and used that as a launching pad for your criminal data manipulation claims.

What you failed mention is that there are other studies on the issue by other research groups that are in agreement with Levitus et al. and in disagreement with Gouretski & Koltermann. Here are couple of recent examples:

Lyman et al. (2010), Robust warming of the global upper ocean
ftp://ftp.soest.hawaii.edu/coastal/C...ing%202010.pdf
Uses different XBT correction methods to arrive to similar results as Levitus et al.

Hamon et al. (2012), Empirical correction of XBT data
http://www.coriolis.eu.org/content/d...1.05082011.pdf

But these are probably also just doing the criminal data manipulation, right?

But Ari I used the paper that Levitus et al responded to in 2009. It was the Gouretski & Koltermann, 2007 paper; which was the reason they redid their study in 2012. The two papers you listed had no bearing on this paper; other than Victor Gouretski was an author of one of the papers and was also an author of the paper you are complaining about. The other paper appears to have been written this year and wouldn’t have been available since the Levitus et al paper was submitted in January of 2012.

Besides I expect that there will be dozens of papers written on this subject as it is a serious problem confronting anyone trying to tie a numeric value on ocean temperature with any degree of certainty.

Also I don’t think whether the ocean is warming is an issue. The issue is whether the warming is unusual compared to the short history we have. And they are trying to do this using a lousy measurement system.

The biggest problem facing anyone trying to salvage the data is trying to separate the yearly XBT measurement data bias from the actual yearly ocean temperature data. Maybe you can explain to me how they will do this?

[profloater]

One aspect I imagine makes the study difficult is the brine concentration. A slight increase in salt content will sink warmer water and volumes of a particular brine density are very slow to mix with other volumes at depth. The surface evaporation must produce a steady stream of higher density brine which in calm conditions will sink. It is necessary therefore to know the dynamics of this to assess deeper waters.

[dgavin]

But Ari I used the paper that Levitus et al responded to in 2009. It was the Gouretski & Koltermann, 2007 paper; which was the reason they redid their study in 2012. The two papers you listed had no bearing on this paper; other than Victor Gouretski was an author of one of the papers and was also an author of the paper you are complaining about. The other paper appears to have been written this year and wouldn’t have been available since the Levitus et al paper was submitted in January of 2012.

Besides I expect that there will be dozens of papers written on this subject as it is a serious problem confronting anyone trying to tie a numeric value on ocean temperature with any degree of certainty.

Also I don’t think whether the ocean is warming is an issue. The issue is whether the warming is unusual compared to the short history we have. And they are trying to do this using a lousy measurement system.

The biggest problem facing anyone trying to salvage the data is trying to separate the yearly XBT measurement data bias from the actual yearly ocean temperature data. Maybe you can explain to me how they will do this?

You are also ignoring other established facts such as Glacial Melting, the loss of 11 out of 12 thermal currents in the Gulf, and a increase of the number of Typhoons (Hurricanes) in the Pacific that make it north of the equator that impact Central or North America (this one was a predicticed consequence of warming made during the early 70's). These are events already noted to have happened, that support Ocean Warming models for many years now.

One paper that contradicts the Ocean Warming models, and thier supporting evidence, is /not/ an adaquate scientific rebuttal, as they offered absolutely no counter evidence to the already gathered evidence that exists in support of Ocean Warming models.

[orionjim]

You are also ignoring other established facts such as Glacial Melting, the loss of 11 out of 12 thermal currents in the Gulf, and a increase of the number of Typhoons (Hurricanes) in the Pacific that make it north of the equator that impact Central or North America (this one was a predicticed consequence of warming made during the early 70's). These are events already noted to have happened, that support Ocean Warming models for many years now.

One paper that contradicts the Ocean Warming models, and thier supporting evidence, is /not/ an adaquate scientific rebuttal, as they offered absolutely no counter evidence to the already gathered evidence that exists in support of Ocean Warming models.

No - I'm only talking about measurement error. I personally think the ocean "is" warming; I'm only questioning anybody's ability to say how much using the system they're using.

[Ari Jokimaki]

But Ari I used the paper that Levitus et al responded to in 2009. It was the Gouretski & Koltermann, 2007 paper; which was the reason they redid their study in 2012. The two papers you listed had no bearing on this paper; other than Victor Gouretski was an author of one of the papers and was also an author of the paper you are complaining about. The other paper appears to have been written this year and wouldn’t have been available since the Levitus et al paper was submitted in January of 2012.

Of course they have bearing on the Levitus et al. Like I said, they offer some examples that use different correction methods and still arrive to similar result. For some reason, you chose only Levitus et al. (out of dozens of already available papers on the subject) to declare that they do criminal data manipulation, which by the way you still haven't backed up with any evidence. So far we only have some seemingly empty declarations from you.

The biggest problem facing anyone trying to salvage the data is trying to separate the yearly XBT measurement data bias from the actual yearly ocean temperature data. Maybe you can explain to me how they will do this?

Standard method, which already has been done, is to compare the measurements to other available measurements, identify a bias, then find out what's causing the problem, and then determine correcting actions. It can be done but it usually is not perfect and in many cases is difficult to do, but that doesn't make it criminal. Perhaps this quote from Levitus et al. might reveal how criminally manipulating their attitude really is:

"We emphasize that our work represents an attempt to correct for observed XBT biases and that more work remains to solve this problem."

[orionjim]

Of course they have bearing on the Levitus et al. Like I said, they offer some examples that use different correction methods and still arrive to similar result. For some reason, you chose only Levitus et al. (out of dozens of already available papers on the subject)…

Because this thread is about the Levitus et al. paper.

Go to the 1st post in this thread and follow along:
Robert has the following:
Link to a graph from
Graph Credit: Adapted from S. Levitus et al., Geophys. Res. Letts.; © AGU 2012

A link to Science Magazine that shows the same graph above and is credited to Levitus et al.

The next link is “This data is from an article since published in Geophysical Research Letters”
which is a link to purchase the S. Levitus et al., paper

Next is GEOPHYSICAL RESEARCH LETTERS, VOL. 39, L10603, 5 PP., 2012
Which if you search for it will give you the Levitus et al. paper

What follow that are about six lines that are quotes from the Levitus et al. paper and then a link to a discussion about the paper at a blog.

And what you will find at the blog are a chart and a link to AR4 containing the chart which is from Levitus et al. 2005. Note that it was this paper that was corrected based on information from the Gouretski & Koltermann, 2007 paper. And then there was the first chart that Robert linked to above that is from the Levitus et al., 2012.

From this point both the blog and Robert drift away from Levitus et al. paper and try to come up with a way to explain the consequences.

…to declare that they do criminal data manipulation, which by the way you still haven't backed up with any evidence. So far we only have some seemingly empty declarations from you.

Ari, I reread what I wrote and find your interpretation totally wrong. I never said Levitus et al. did anything criminal. I suggest contacting a moderator and let them decide instead of trying to insult me.

…
Perhaps this quote from Levitus et al. might reveal how criminally manipulating their attitude really is:

"We emphasize that our work represents an attempt to correct for observed XBT biases and that more work remains to solve this problem."

Again, contact a moderator instead of insulting me. I’ve already explained “data manipulation”.

[Ari Jokimaki]

Because this thread is about the Levitus et al. paper.

Not quite good enough because you chose to present Gouretski & Koltermann result as truth and then based on that made insulting comments of Levitus et al. In such a situation one should present the whole truth, which in this case seems to be that Gouretski & Koltermann result is an outlier compared to other studies. Instead, you presented it as a sort of 50-50 situation.

Ari, I reread what I wrote and find your interpretation totally wrong. I never said Levitus et al. did anything criminal.

Sure, you just hinted it. This was what you said:

"You have a group of people writing a paper that was supposed to be the De Facto Standard on ocean warming and they never took the time to understand the measurement system being used. (I say this because if they did take the time and knew about the bias, then what they did was criminal.)"

So, you suggest here either that they don't know what they are doing, or that they have done something criminal. When we are talking about experts in their field, it is quite safe to say that you actually are suggesting that they have done something criminal even if you present the case so that you can later claim you didn't say that. And after doing something like this, you try the poor victim act.

[Swift]

Again, contact a moderator instead of insulting me. I’ve already explained “data manipulation”.

So, you suggest here either that they don't know what they are doing, or that they have done something criminal. When we are talking about experts in their field, it is quite safe to say that you actually are suggesting that they have done something criminal even if you present the case so that you can later claim you didn't say that. And after doing something like this, you try the poor victim act.

Both of you, but particularly Ari, need to tone it down. Stop with wordsmithing each other's post, looking for hidden meanings. Stop with acting as moderators. And stop with trying to score points against each other. If you two can't stick to the science, and keep making this a personal battle, further moderator actions will be taken.

[Robert Tulip]

I would suggest looking into the history of the papers by Levitus et al. They’ve written several papers on ocean warming prior to the paper released in 2012.

Then read this paper published in 2007 by Gouretski and Koltermann; it showed that the XBT and CTD measurement systems used in taking the ocean temperature data had a .2c to .4c bias. Compare that bias to the final result of the Levitus el al papers conclusion and your interpretation of it.

You can find the Gouretski and Koltermann paper here:
http://epic.awi.de/17644/1/Gou2007a.pdf

Levitus et al wrote a reply in 2009 that can be found here:
ftp://ftp.nodc.noaa.gov/pub/data.nod.../grlheat08.pdf

This reply explains what they found and how they would manipulate the data for future papers. You really need to read this paper; because I can’t believe that anyone that does would have a warm and fuzzy feeling about any results that are produced with the manipulations they’re using.

The 2012 paper uses the data manipulations they defined in the 2009 paper. And remember when looking at the error bars in their plots and think about the .2c to .4c bias (remember this is only bias and does not address precision or repeatability of the measurement system). And also think about the date the XBT bottles were manufactured influencing the bias and how they handled that. (This was defined by Wijffels et al.[2008]).

FWIW, you could have gotten their 2012 paper here for free:
ftp://ftp.nodc.noaa.gov/pub/data.nod.../grlheat12.pdf

Thanks, I've now read these papers. I'm sorry but I can't really understand the status of the debate between Levitus and Gouretski & Koltermann as it is conducted in such technical language. It seems all agree the ocean is warming, but the scale and pace of change are difficult to state with precision due to uncertainty about accuracy of early temperature measurements. The discussion uses joules, but G&K don't provide graphs or temperature measures that would simply show a non-expert what they see as the demonstrated parameters of the observed ocean warming. And Levitus in his 2009 paper cites other authors whose data he says supports his interpretation. It is all somewhat confusing for a topic that is central to scientific analysis of global warming.

[orionjim]

Thanks, I've now read these papers. I'm sorry but I can't really understand the status of the debate between Levitus and Gouretski & Koltermann as it is conducted in such technical language. It seems all agree the ocean is warming, but the scale and pace of change are difficult to state with precision due to uncertainty about accuracy of early temperature measurements. The discussion uses joules, but G&K don't provide graphs or temperature measures that would simply show a non-expert what they see as the demonstrated parameters of the observed ocean warming. And Levitus in his 2009 paper cites other authors whose data he says supports his interpretation. It is all somewhat confusing for a topic that is central to scientific analysis of global warming.

I wouldn’t really call it a debate but more of a discovery of the amount of bias in the XBT units that are used for measuring temperature at different depths.

Here is a link to a series of PowerPoint presentations that get at the problem.
http://www.aoml.noaa.gov/phod/goos/m.../XBT/index.php

The actual problem is fairly easy to understand. The real problem comes in trying to figure out where and when the bias enters the picture. The Workshop was setup to see if they could come up with a different fall rate equation. The fall rate equations could reduce the amount of measurement variation in the data. But to remove the yearly bias would require either comparisons to calibrated units or finding causes of changes to the system that produces the devices.

It’s fairly easy to go through the slides and watch for anything that is either comparison related or date related that might be a cause or a place in time they can actually compare the XBT units against other type of measurement devices and if they can then attach a bias value to that timeframe.

I think most people agree that the ocean is warming; the only real issue is how much.

[Veiligo]

Speaking as a layperson, the kind of measure that non-scientists would understand and appreciate would be:

1) What are the consequences of ocean warming, and if the trend continues what could happen in the future? i.e. show why this is important
2) At what rate does the ocean normally cool or warm? i.e. show that such a small number is actually a dramatic and alarming change people need to take note of
3) If the same amount of energy had been poured into the atmosphere what temperature rise would have been observed there? For a meaningful comparison that people can grasp

Just as an alternative to Sydney Harbour. Is it even possible to answer these questions?

[Robert Tulip]

Speaking as a layperson, the kind of measure that non-scientists would understand and appreciate would be:

1) What are the consequences of ocean warming, and if the trend continues what could happen in the future? i.e. show why this is important

A Discordant Sea: Global Warming and its Effect on Marine Populations by Nicole Lindell says rising air temperatures affect the physical nature of our oceans. As air temperatures rise, water becomes less dense and separates from a nutrient-filled cold layer below. This is the basis for a chain effect that impacts all marine life who count on these nutrients for survival.

There are two general physical effects of ocean warming on marine populations that are crucial to consider: Changes in natural habitats and food supply, and changing ocean chemistry/acidification.

(From NOAA: Ocean deserts, areas of low surface chlorophyll, are increasing in size, apparently due to the reduced interchange between upper and lower levels of the ocean due to warming. These desert areas were estimated at more than 50 million square kilometers in 2008.)

Since oceans are warmer, nutrients are blocked from traveling upward to these suppliers that are limited to a small surface layer and therefore cannot supplement marine life with necessary organic carbon and oxygen. The entire food chain is affected. Animals that once traveled to the surface for food are now finding an area void of nutrients and light-driven creatures are starting their growth cycles at different times.

Greater CO2 concentrations released into our oceans increase ocean acidity. This results in less ocean plants able to uptake greenhouse gases. Also, increased ocean acidity threatens marine life, such as corals and shellfish, which may become extinct later this century from the chemical effects of CO2. Coral secretes calcium carbonate to form its skeleton. Acidification reduces growth and strength of corals.

Coral bleaching, the breakdown in the symbiotic relationship between coral and algae, is also occurring with warmer ocean temperatures, destroying food and habitats for a great number of marine life. As coral reefs die, we will lose an entire ecological habitat of fish. Ocean circulation changes due to warming would have disastrous impacts on marine fisheries.

Fifty-five million years ago, ocean acidification led to a mass extinction of ocean creatures. According to our fossil record, it took more than 100,000 years for the oceans to recover.

2) At what rate does the ocean normally cool or warm? i.e. show that such a small number is actually a dramatic and alarming change people need to take note of

Levitus attributes the entire warming measured since 1950 to anthropogenic emissions.

3) If the same amount of energy had been poured into the atmosphere what temperature rise would have been observed there? For a meaningful comparison that people can grasp?

Levitus et al (2012) state "We have estimated an increase of 24x10^22 Joules representing a volume mean warming of 0.09° Celsius of the 0–2000 meter layer of the World Ocean. If this heat were instantly transferred to the lower 10 km of the global atmosphere it would result in a volume mean warming of this atmospheric layer by approximately 36°C (65°F). This transfer of course will not happen; earth’s climate system simply does not work like this. But this computation does provide a perspective on the amount of heating that the earth system has undergone since 1955."

My calculation above was that if the amount of extra heat we are putting into the ocean went into an Olympic swimming pool it would boil it in about two milliseconds. In the minute it takes the swimmers at the London Olympics to complete a 100 meter race, enough heat is added to the oceans to bring more than 20,000 Olympic swimming pools to boiling point.

[Veiligo]

Thanks for the full reply. Also, I now feel kind of stupid because some of that info was actually in the OP, I just missed it. Sorry to make you repeat it

[Swift]

From R&D magazine on-line

New research by a team of Lawrence Livermore National Laboratory (LLNL) scientists and international collaborators shows that the observed ocean warming over the last 50 years is consistent with climate models only if the models include the impacts of observed increases in greenhouse gas during the 20th century.

Though the new research is not the first study to identify a human influence on observed ocean warming, it is the first to provide an in-depth examination of how observational and modeling uncertainties impact the conclusion that humans are primarily responsible.

"We have taken a closer look at factors that influence these results," said Peter Gleckler, an LLNL climate scientist and lead author of the new study that appears in Nature Climate Change. "The bottom line is that this study substantially strengthens the conclusion that most of the observed global ocean warming over the past 50 years is attributable to human activities."

The group looked at the average temperature (or heat content) in the upper layers of the ocean. The observed global average ocean warming (from the surface to 700 m) is approximately 0.025 C per decade, or slightly more than 1/10th of a degree Celsius over 50 years. The sub-surface ocean warming is noticeably less than the observed Earth surface warming, primarily because of the relatively slow transfer of ocean surface warming to lower depths. Nevertheless, because of the ocean's enormous heat capacity, the oceans likely account for more than 90% of the heat accumulated over the past 50 years as the Earth has warmed.