Climate science seems to be immensely complex – while that might be true for any attempt to correctly simulate the climate – there are some parts which are quite easy.
This is an easy, traceable step by step calculation of the current global energy imbalance based on observed ocean warming. I will also show that the values are similar to other attempts to quantify current global energy accumulation.
Please note that the only reason why I use the last 10 years, is that the ARGO buoys have only provided temperature measurements of the oceans down to 2000 m depth in the oceans for about so long. Hence I believe this is the most reliable temperature measurements we have for the oceans.
I will, for now, disregard any homogenization or adjustments of the ocean records and just uncritically use the provided values. I will also have to disregard uncertainty estimates – as I can´t find decent uncertainty estimates, in accordance with the international standards for expression of uncertainty, readily available to me.
The following curve is generated by the KNMI climate explorer by selecting: Ocean mean temperature; 0-2000 m; 2005 – 2015 and 12 months low pass filter:
For 0 – 2000m I find the following:
From this figure we can simply take the difference between the first point in the time series and last point in the time series. I would say the observed warming of the oceans from 0 – 2000 m depth from 2005 to 2015 is pretty close to 0, 045 K. I will use that value in my estimate.
The following table contains all the steps involved in estimation of current global energy accumulation, or current global energy imbalance if you like.
The steps should be quite easy to follow, just by observing how the unit changes in each step. However, the calculations are contained in this spread sheet: 2016-07-14 How to estimate current energy imbalance from ocean warming .
You will see that I prefer the scientific number format. There are a number of reasons for that, the main reason is that I think everything gets simpler and more robust by using this format. I hope you will learn to like it just as I did.
You will also find that the table contains link to the sources for all input parameters and values.
|Mass of all the oceans = 1,4 E18 metric tons||kg||
|Volume of oceans from 0 – 2000 m / volume of all the oceans
-52% of ocean volume below 2000 m
That obviously means that about 48% of the ocean volume is above 2000 meters.
|Specific heat capacity for ocean water||J / kg*K||
|Heat capacity for the oceans from 0 – 2000 m depth||J / K||
|Observed ocean warming; 0-2000 m ; 2005-2015
See figure above from KNMI climate explorer;
|K / 10year||
|Estimated amount of energy required for the observed increase of temperature||J / 10year||
|Estimated amount of energy required for the observed increase of temperature||J / 1year||
|Number of seconds per year||s / 1year||
|Estimated amount of energy accumulation in relevant part of the oceans||J / s||
|Estimated amount of energy going into relevant part of the oceans||W||
|Fraction of energy going into the relevant part of the oceans
«Ocean warming dominates the global energy change inventory. Warming of the ocean accounts for about 93% of the increase in the Earth’s energy inventory between 1971 and 2010 (high confidence), with warming of the upper (0 to 700 m) ocean accounting for about 64% of the total.
Warming of the ocean between 700 and 2000 m likely contributed about 30% of the total increase in global ocean heat content (0 to 2000 m) between 1957 and 2009.»
Ref. IPCC; WG1;AR5; Oceans; executive summary; Temperature and Heat Content Changes
|Estimated global energy accumulation, «global energy imbalance» based on observed warming of the oceans from 0 – 2000m||W||
|Global surface area 510,072,200 km2||m2||
|Estimated current global energy accumulation; based on observed warming of the oceans from 0 – 2000 m; year 2005 – 2015; and IPCC estimates for how much warming is expected to go into that part of the oceans||W / m2||
Table 1: Estimated global energy imbalance based on: KNMI Observed ocean warming 0-2000 m depth from 2005 – 2015 and IPCC´s expected amount of energy going into the oceans.
Based on reported ocean warming; 0-2000 m depth; from 2005 to 2015 (in the ARGO era); IPCC estimate for amount of warming going into the oceans; I have estimated that the current global energy imbalance is: 0,8 W/m^2.
Here are some other values for the same quantity:
Wikipedia; Earth´s energy budget:
Earth’s energy imbalance
If the incoming energy flux is not equal to the outgoing thermal radiation, the result is an energy imbalance, resulting in net heat added to or lost by the planet (if the incoming flux is larger or smaller than the outgoing). Earth’s energy imbalance measurements provided by Argo floats detected accumulation of ocean heat content (OHC). The estimated imbalance was measured during a deep solar minimum of 2005-2010 at 0.58 ± 0.15 W/m². Later research estimated the surface energy imbalance to be 0.60 ± 0.17 W/m².” – Wikipedia Earth’s energy budget
United Nations climate panel IPCC:
TS.2.3 Changes in Energy Budget and Heat Content
… Ocean warming dominates that total heating rate, with full ocean depth warming accounting for about 93% (high confidence), and warming of the upper (0 to 700 m) ocean accounting for about 64%. Melting ice (including Arctic sea ice, ice sheets and glaciers) and warming of the continents each account for 3% of the total. Warming of the atmosphere makes up the remaining 1%.
The 1971–2010 estimated rate of ocean energy gain is 199 × 10^12 W from a linear fit to data over that time period, equivalent to 0.42 W m–2 heating applied continuously over the Earth’s entire surface, and 0.55 W m–2 for the portion owing to ocean warming applied over the ocean’s entire surface area. The Earth’s estimated energy increase from 1993 to 2010 is 163 [127 to 201] × 10^21 J with a trend estimate of 275 × 10^15 W. The ocean portion of the trend for 1993–2010 is 257 × 10^12 W, equivalent to a mean heat flux into the ocean of 0.71 W m–2.
IPCC;AR5;WGI; Technical Summary ; TS.2.3; page 39.
It should be noted however, that the 0,71 W/m^2 value provided by IPCC is only the energy estimated to go into the oceans. As this is estimated to be 93 % of the global energy accumulation 0,71 W/m^2 should be divided by 0,93 to get the global energy accumulation.
0,71 W/m^2 divided by 0,93 is equal to 0,76 W/m^2.
Hence, my estimate of 0,8 W/m^2 for current global energy accumulation, or current global energy imbalance if you like, seem to be corroborated by similar values from other sources. However, I´m not able to provide an uncertainty estimate for my central estimate.
Another question will off course be: Can we trust the ocean temperature records provided by NODC?
(NODC Used to be: National Oceanographic Data Center (NODC) the center is now within the National Oceanic and Atmospheric Administration NOAA; National Centers for Environmental Information.)
As I´m completely independent, unfunded and anonymous – and as I don´t depend on funding by United States government or by any other government, I am free to say exactly what I think about this.
And what I think about this is that Tony Heller has provided compelling evidence for governmental manipulation of temperature records: NOAA US Temperature Fraud
So the simple answer to this is: NO! We cannot take for granted that the record provided by NODC provides an unbiased estimate for ocean temperature. Unfortunately I don´t currently know where to get readily available and independent temperature records.