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Comments 44051 to 44100:

44051. DSL at 12:20 PM on 4 July 2013
       Climate change science: what’s in a name?
       

       I often explain it thusly:

       "'Global warming' refers to temperature increase, but climate is much more than temperature.  It's also wind, rain, snow, ocean currents, etc.  Climate change is change in all of those elements as a result of increased temperature. It's not that everything stays the same but gets hotter.  Everything changes--it gets hotter, winds change, the jet stream changes, precipitation changes, ocean currents change: climate changes." 

44052. villabolo at 10:52 AM on 4 July 2013
       Climate change science: what’s in a name?
       

       Some short answers and talking points that could be understood at a High School level:

       In order to explain the difference between Global Warming and Climate Change we can say:

       "Global Warming is the cause, Climate Change is the result."

       In order to give the shortest answer possible to the issue of our erratic weather we can say: 

       "The Earth is 1.4 degrees Fahrenheit higher than before while the Arctic is 3-5F and up to 10-18F above normal at certain times and places. This creates a chain reaction of events that give us cold winters and hot summers. However the heat records exceed the cold records."

       In order to grab people's attention to the results of Global Warming we can say:

       "When the Arctic Ocean loses its ice we start to lose our crops due to severe weather."

       In order to explain the leveling off of temperatures we can say:

       "Temperatures rose in 1978 and then leveled off followed by another rise in 1998 which also leveled off even though the sun started cooling off in 2002 and went low in 2010. Now that the sun is getting back up to normal we're going to get even higher temperatures."

44053. Chris G at 09:26 AM on 4 July 2013
       Climate change science: what’s in a name?
       

       Using the word 'energy' instead of 'heat':  Yes, the tradeoff between energy not being as salient as heat (to the layman) and heat not really capturing the meaning correctly is most often worth it.

        

       I also agree that a fair percentage of the contrarian arguments I see are a result of the person believing that the simple explanation implies something it does not.  Possibly they are motivated to find flaws with the explanation and so interpret an ambiguous, simple explanation in the least favorable way.

44054. Rob Honeycutt at 08:00 AM on 4 July 2013
       There is no consensus
       

       participley...  The wiki page on the scientific opinion on climate change they have this statement regarding dissenting opinions:

       "As of 2007, when the American Association of Petroleum Geologists released a revised statement,[11] no scientific body of national or international standing rejected the findings of human-induced effects on climate change.[10][12]"

       If anyone can find a legitimately recognised scientific body that rejects climate change, I think everyone here would be interested to know about it.

44055. DSL at 07:23 AM on 4 July 2013
       There is no consensus
       

       I should also point out that it's unlikely that any organization of professional scientists would actually issue a statement rejecting the theory.  Such a move would require evidence, and no such evidence exists.

44056. DSL at 07:19 AM on 4 July 2013
       There is no consensus
       

       Participley, as far as I know, no one has published a complete list of scientific organizations' positions on AGW.  However, the professional denial industry hasn't located any organizations that disagree, and they'd be the ones most anxious to find such an organization.  Perhaps you can locate one? 

44057. william5331 at 06:29 AM on 4 July 2013
       Understanding the long-term carbon-cycle: weathering of rocks - a vitally important carbon-sink
       

       Our decendants a few thousand years from now will be grateful for the geological carbon sink but we need to encourage and preserve carbon sinks that act a tad quicker if we are to live to leave such decendants.  Fabulous article.

       http://mtkass.blogspot.co.nz/2012/02/carbon-sinks.html

44058. Rob Painting at 06:10 AM on 4 July 2013
       4 Hiroshima bombs worth of heat per second
       

       arncliffe - the thin cool-skin layer of the ocean already is an insulating barrier. Warming the atmosphere, through additonal greenhouse gas emissions, simply increases the efficiency of that insulating barrier. 

       Reduced equatorial cloud cover during La Nina (due to the cooler sea surface temperature), combined with the strong upwelling (Ekman suction) in the eastern equatorial Pacific, does indeed lead to greater warming of the ocean - because it's bringing cool subsurface water to the surface, where it can be heated by the sun. I briefly touched on that in this post: Search For 'Missing Heat' Confirms More Global Warming 'In The Pipeline'. 

       Once the posts explaining the wind-driven ocean circulation and deep ocean warming are completed, it will be definitely worthwhile explaining how all the pieces of the puzzle fit together. Many readers overlook the obvious implications.

44059. participley at 05:47 AM on 4 July 2013
       There is no consensus
       

       "There are no national or major scientific institutions anywhere in the world that dispute the theory of anthropogenic climate change. Not one."

       Is there a reference for this statement ?

44060. rockytom at 05:32 AM on 4 July 2013
       Understanding the long-term carbon-cycle: weathering of rocks - a vitally important carbon-sink
       

       Absolutely a fine article, John.  A great deal of the information will aid me in updating the Ph.D. I received in 1968, although I did use Turner and Verhoogan as a textbook in "Igneous and Metamorphic Petrology."  I look forward to your next post.  BTW, in the next version of the excellent illustration beginningthe article could you show a more obviously continuous and recently uplifted mountain range and label it as such?  This would possibly have more significance to incipient geologists and emphasize the importance of exposing newly elevated rock to the weathing (re: rock) cycle.

44061. David Kirtley at 04:29 AM on 4 July 2013
       Climate change science: what’s in a name?
       

       Contrarian cries that us alarmists are trying to change "global warming" to a new name in 1, 2, 3...

44062. BillEverett at 03:34 AM on 4 July 2013
       Climate change science: what’s in a name?
       

       "To the public it can appear that there is less warming, because the rate of temperature increase at the Earth’s surface has slowed down in the last decade."

       According to the World Meteorolgical Organization, "The decadal rate of increase in the global temperature accelerated between 1971 and 2010. The global temperature increased at an average estimated rate of 0.17°C per decade during that period, compared with 0.062°C per decade for the entire 1880-2010 period. The average 2001-2010 decadal temperature was 0.21°C warmer than 1991–2000, which in turn was +0.14°C warmer than 1981-1990."

       WMO Press Release 3 July 2013

       Moderator Response:

       Sure, but sceptics look at short term data, preferably picking a really hot outlier like 1998 as the baseline. The Escalator shows the how the trick works...but anyway:

       "The planet has continued to accumulate heat since 1998 - global warming is still happening. Nevertheless, surface temperatures show much internal variability due to heat exchange between the ocean and atmosphere. 1998 was an unusually hot year due to a strong El Nino."

       What has global warming done since 1998?

44063. arncliffe at 02:35 AM on 4 July 2013
       4 Hiroshima bombs worth of heat per second
       

       Bob Painting:

       Sorry-first para: your paper of OCTOBER 2011

44064. arncliffe at 02:04 AM on 4 July 2013
       4 Hiroshima bombs worth of heat per second
       

       Rob Painting @

       In my reply to Glenn Tamblyn I was referring to your recent article on climate shift that only referenced the Tangaroa experiments. I have subsequently found your article of June 2011 with the references that you mention. In simple terms it seems that the effect of downwelling LR radiation is not to heat the ocean directly, but to turn the thin cool skin layer into a thermal insulating barrier and thus increase OHC by reducing heat transmission to the atmosphere. Is this a reasonable summary?

       You mention Bob Tynsdale: whilst I do not subscribe to his view that that global warming has nothing to do with CO2 but is caused by ENSO, his position on the ability of ENSO neutral and La Nina modes to increase OHC seems similar to yours.

44065. ajki at 01:28 AM on 4 July 2013
       Climate change science: what’s in a name?
       

       I've said it before and I say it again: that one phrase I'd like to see above all other nice&true facts and figures is "AGW".

       
       Global: it's NOT about weather, it's not about your hometown or the hometowns of your beloved ones, it's not about your country or continent - it's about the whole blue Marble. Go see a nice picture of it - there are legions out there.

       
       Warming: it's NOT about models that you can endlessly quibble about, it's not about plant food, it's not about more greening in the north or deep south. It's about measuring of temperatures just everywhere and finding one clear trend: upwards - hence warming.

       Anthropogenic caused: it's not about your or mine moral guiltyness, it's not about your nice car and house, it's not about your really perfect energy consuming footprint. It's about keeping warm little fires burning by 7 Billion of you and me.

       
       And the one figure I'd like to see is

       

       
       but without any model projection.

       
       The title should be: Rise of Man

       There should be two points in it with a legend: one before the rise named "1 Billion of you and me" and the second at the momentary end of the measured data points named "You and me and the other 7 Billion are here!"

44066. philipm at 19:32 PM on 3 July 2013
       Agnotology, Climastrology, and Replicability Examined in a New Study
       

       Where do these guys learn their stuff? In my first year applied maths course, a lecturer told us that interpolation can give useful results, but extrapolation should be treated with extreme caution -- if it purely amounted to curve fitting.

       I also recall the mantra "correlation is not causation" from the denial camp when the theory of climate change was a bit less complete than it is now. Funny how the argument they used then against the theory almost entirely applies now to them.

       A deep fundamental problem in public perception of science is the desire of the media to portray the big breakthrough. This very rarely happens and may only be recognised in retrospect after a lot of retries of an apparently failed experiment.

44067. John Mason at 18:55 PM on 3 July 2013
       Understanding the long-term carbon-cycle: weathering of rocks - a vitally important carbon-sink
       

       @Slioch - absolutely - the key minerals are the plagioclase feldspars (the calcic ones), mg-rich members of the olivine group and Ca/Mg rich pyroxenes and amphiboles. Granite - the coarse-grained, intrusive equivalent of rhyolite - likewise tends to have Ca and Mg contents in a similar range, present in plagioclase feldspar. However, it could be argued that the weathering of granite is still significant simply because granite is such an abundant rock-type, both in its primary state and as detritus making up sedimentary rocks. Incidentally, the propensity of rok-forming minerals to weathering is roughly as follows, starting at most susceptible and ending with least susceptible (note that there is a continuous compositional series between the sodi and calcic end-members of the plagioclase feldspar group):

       Olivine, Plagioclase (calcic)

       Pyroxene

       Amphibole

       Biotite (black mica), Plagioclase (sodic)

       Orthoclase

       Muscovite (white mica)

       Quartz

       If you visit the famous china clay-pits of Cornwall, which exploit altered and weathered granite, you will find that it is the feldspar that has decomposed: the waste-heaps left after the kaolinite (one of the weathering-products) has been extracted are the residual, relatively unscathed quartz and mica.

        

44068. Kevin C at 18:33 PM on 3 July 2013
       4 Hiroshima bombs worth of heat per second
       

       While I have enormouse respect for Robert Rhode's work at BEST, the rest of that paper wouldn't have passed review in a climate journal.

       "We are not aware of any global climate models that predicted the reversal of slope that we observe."

       That's weasel wording for "The diurnal temperature literature looked difficult, so we didn't read it".
       
       There is an extensive literature on diurnal temperature range and it is far more complicated than the BEST paper makes out. DTR does decrease with greenhouse forcing, but is much more strongly influenced by aerosols, clouds, soil moisture and so on, as even two minutes with google scholar will reveal.
       
       To be fair SkS's material on DTR is similarly lacking in nuance - it's on my list of things to fix if we ever get a breathing space between debunking new nonsense. Glenn is correct that in the absence of other factors solar warming would cause an increase in DTR, however the other influences are sufficiently large that we would have to eliminate them to draw a strong conclusion from this effect alone. Drost et al use multiple fingerprints in combination to obtain a much more robust result.
       
       More compelling still is the fact that we can see the increase in greenhouse warming in both the outgoing infrared radiation spectrum, and in the infrared glow looking up at greenhouse gases from the surface.

44069. Slioch at 17:33 PM on 3 July 2013
       Understanding the long-term carbon-cycle: weathering of rocks - a vitally important carbon-sink
       

       Silicate rocks are a complex mix of (mostly) silicate minerals. These minerals do not have a fixed composition: in feldspars, for example, sodium, potassium and calcium (and other) atoms can substitute for one another, and the exact composition of the feldspar crystal depends upon both the composition of the melt from which it crystallised and the temperature and pressure at which it did so. Thus, the composition of silicate rocks is more easily and accurately recorded as a list of oxides of various amounts, rather than of minerals per se. For example, a typical basalt lava has the following composition:

       SiO2 49.06%

       TiO2 1.36%

       Al2O3 15.70%

       Fe2O3 5.38%

       FeO 6.37%

       MnO 0.31%

       MgO 6.17%

       CaO 8.95%

       Na2O 3.11%

       K2O 1.52%

       H2O 1.62%

       P2O5 0.45%  (from Turner and Verhoogan, "Igneous and Metamorphic Petrology").

       Giving the composition of silicate rocks in this way enables one to immediately appreciate their potential for carbon sequestration via weathering, in this case, from the 8.95% of CaO and 6.17% MgO. Another (less common) extrusive igneous rock called rhyolite has only 1.22% CaO and 0.38% MgO and has thus much less potential for carbon sequestration.

44070. JasonB at 15:45 PM on 3 July 2013
       4 Hiroshima bombs worth of heat per second
       

       I had a quick look and found the claim in the BEST paper here: http://www.scitechnol.com/GIGS/GIGS-1-101.php

       Specifically, Figure 4 on page 4 shows a decline in diurnal range from 1900 to 1987, followed by an increase in diurnal range:

       

       The paragraphs above the figure note that "The rise takes place during a period when, according to the IPCC report, the anthropogenic effect of global warming is evident above the background variations from natural causes" and "We are not aware of any global climate models that predicted the reversal of slope that we observe".

       Personally, I wouldn't be rushing to point to this as evidence that the current understanding of AGW is wrong.

       Firstly, the recent figures don't like look like they stand out with respect to the long-term trend extrapolated forward from about 1970; the steep decline from the late 60s to the mid 80s followed by the rebound back up to the long-term trend is perhaps the portion that needs explaining. Indeed, the steep incline seems to have levelled off again.

       Secondly, even with that dip and recovery, there is still an overall decline on longer time scales, exactly as expected. Although BEST are fairly confident in their results as shown by their uncertainty estimates, I think they are talking about the uncertainty in the true value, not the uncertainty introduced by short-term fluctuations about the trend. The highly "certain" dip and recovery could well be a highly certain natural variation that is in no way unusual (the uncertainty in the earlier figures makes that hard to determine) and it could be that, in fact, there was no change in the long term trend underlying that natural variability. (In other words, even if the monthly anomalies reported for GISTEMP, for example, were accurate to 0.00001 degrees, it wouldn't change the fact that we'd need well over a decade of readings to ascertain the long-term trend, because the variability is real feature of the system and not simply a measurement error.) Since temperature readings are affected by more than just CO2, it's possible that the diurnal temperature range is, too.

       Thirdly, this is just one study by one group. As it notes, four previous studies reported significant decreases in the diurnal temperature range.

44071. JasonB at 10:13 AM on 3 July 2013
       Media Overlooking 90% of Global Warming
       

       netprophet,

       As KR mentioned, space for solar isn't a problem. Using an existing parabolic trough system like Nevada Solar One as a benchmark (134 GWh/year, 1.6km²) you could generate the entire planet’s current annual energy consumption (not just electricity) using just 17% of the Sahara desert.

       Consider also the fact that we have already disturbed, by coal mining, an area (~8.4 million acres in the US alone) equal to that required to provide all power using solar thermal, and that coal mining has a much bigger impact on the area affected than simply putting it in the shade, and that coal also usually happens to be located in much higher-value areas than solar thermal plants would be.

       Solar PV is even less of an issue, because it can sit on existing rooftops, and it has the advantage that it's competing with the end-user retail price of electricity.

       If you're worried about cost, however, then you should be comparing to wind, rather than solar. Wind is now cheaper than new coal, which is why it's had such a dominant position in terms of new installed capacity for a while now. (Going forward, you can see the EIA's current estimates for 2018 here. Note that those figures are excluding "targeted tax credits such as the production or investment tax credit available for some technologies".) Wind can also co-exist with other uses of the land (most wind farms I've seen have been on working farms running sheep and cattle).

44072. KR at 09:32 AM on 3 July 2013
       4 Hiroshima bombs worth of heat per second
       

       arncliffe - "...a paper published last year by the team at BEST showed that the gap between night and day temperatures has actually been increasing for some twenty five years."

       That's not what the data shows - Vose et al 2005; "Minimum temperature increased about twice as fast as maximum temperature over global land areas since 1950, resulting in a broad decline in the diurnal temperature range...", and Zhou et al 2009; "Observations show that the surface diurnal temperature range (DTR) has decreased since 1950s over most global land areas..." would disagree. 

       If you have a reference, it would be interesting to look at - but your assertion is contrary to the data I know of. 

44073. Manwichstick at 07:10 AM on 3 July 2013
       4 Hiroshima bombs worth of heat per second
       

       @arncliffe

       I would be very skeptical of the claim:

        the team at BEST showed that the gap between night and day temperatures has actually been increasing for some twenty five years.

       Not in my country, Canada. Winters are warming faster than summers and daytime minimums are increasing faster than daytime maximums. Just as predicted.

       And BTW, if someone provides you with data, or explictly argues, that the sun is magically, or increasing some sort of output that is the cause of the earth's additional heat accumulation... they are instantly not a trustworthy source.

44074. KR at 06:13 AM on 3 July 2013
       Media Overlooking 90% of Global Warming
       

       netprophet - I don't believe either cost or area is a serious concern. I would suggest looking at one of the Renewable Baseload Energy threads, where this has been discussed in detail. 

       Space is simply not a problem - here are some maps indicating required generation area for solar or for wind:

       

       

       [Source]

       As to cost, Apple hasn't released figures, but it's estimated to be similar to the cost of its other data centers - all of which are powered from renewable energy sources, and none of which has bankrupted the quite profitable company. 

44075. Dumb Scientist at 05:14 AM on 3 July 2013
       The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
       

       I set "custom" parameters equal to mine (with my 7th order human influence, etc.) but with Dr. Tung's noise parameters, and 10,000 runs seemed to show that the sensitivity to smoothing was similar to simulations using Dr. Tung's overall parameters. This would have suggested that my simulation's sensitivity to smoothing the AMO index was related to the relative noise levels. However, running 100,000 simulations of the custom parameters reveals sensitivity similar to my overall parameters, so my hypothesis was wrong.

       I still don't know why my simulation is more sensitive to smoothing, but I think the important point is still that my parameters produce more realistic timeseries, correlations, variances, and error bars. (Also, attribution is still really a thermodynamics problem.)

44076. Rob Painting at 05:03 AM on 3 July 2013
       4 Hiroshima bombs worth of heat per second
       

       Arncliffe - 1.My post on the cool-skin layer of the ocean hyper-links to 3 different papers on the topic, and those three papers cites numerous others in support of the physics, math, and observations involved. Climate science contrarians on the other hand cite none. Why do you think that is?

       2. The simple experiment carried out by Professor Minnett whilst aboard the New Zealand research vessel Tangaroa (Maori for the god of the sea) is rather compelling. Why else would the surface waters warm under cloudy conditions? The typical contrarian response of furious handwaving is not an explanation.

       3. The amount of sunlight reaching Earth has declined over the last 3 decades due to a decline in the sun's radiation output. Instead of a decline in ocean heat content, we have seen a dramatic increase - as the greenhouse gas-forcing of the ocean's cool-skin layer predicts.

       4. Attempts to blame current ocean warming on natural factors are generally by people who have little understanding of oceanography - such as the contrarian Bob Tisdale, and whose ideas are contradicted by the observations. 

       5. For example, mainstream science not only correctly predicted the current ocean warming, but accounts all previous Earth warming episodes that involved increased atmospheric concentrations of greenhouse gases - due to the fact that over 90% of heat goes into the oceans. The clearest illustration of this is the correlation between global temperature and atmospheric carbon dioxide (the main greenhouse gas) as shown in the ice core records dating back 800,000 years. The last 400,000 years of which is shown below:

       

        

       How does Bob Tisdale's idea fare when you run it backward in time?

44077. arncliffe at 04:49 AM on 3 July 2013
       4 Hiroshima bombs worth of heat per second
       

       Glenn Tamblyn

       Sorry, another error: para 5  - Four Hiroshima bombs PER SECOND

44078. netprophet at 04:42 AM on 3 July 2013
       Media Overlooking 90% of Global Warming
       

       Okay, let's assume we must act now as the President expects all Americans to do.  Apple announced today it is putting a 43,500 kwhr (~20 MW unit) generating solar plant in Reno, NV.  It is equivalent to the carbon generation of some 17,000+ homes.  The capital cost will be ~ $75M based on costs of similar sized plants.  In order to replace coal, which generates 1,517,000,000,000 kwhr, with solar, we would need some 35,000 such Apple size plants if the entire US had the sunlight of NV which it doesn't.  Adjusting for many cloudy regions, we would need more like 70,000 such plants.  The total investement would be over $5.0 trillion and in many regions there simply isn't enough space to put solar panels.  How would we fund this? 

44079. shoyemore at 02:52 AM on 3 July 2013
       4 Hiroshima bombs worth of heat per second
       

       Taking Tom Curtis' point about etnropy, the energy accumulating in the atmosphere was once of high entropy, when it began in the sun's thermonuclear furnace. So the proviso around the "4 Hiroshima bombs" can be posed as "If we express this energy in units appropriate to where it began .... ", relateable to the sun's arriving energy on earth.

       It still carries the image of a lorra, lorra energy, which is why I like it. And people can express it in more than one way .... "Here are different ways you can express this energy .. 4 Hiroshima bombs per second, or illuminating 71 billion Wembley sized areas with thirty five 100 Watt bulbs .... "

       Obviously, no one should use the unit if they feel uncomfortable with its accompanying imagery, but a concrete example that you can explain is very usful.

       Stephen Schneider: Each of us has to decide what the right balance is between being effective and being honest. I hope that means being both.

44080. arncliffe at 02:50 AM on 3 July 2013
       4 Hiroshima bombs worth of heat per second
       

       Glenn Tamblyn 

       Whoops Typo: 4th para - winds that move this mass of upwelling waterWESTWARD

44081. arncliffe at 02:45 AM on 3 July 2013
       4 Hiroshima bombs worth of heat per second
       

       Glenn Tamblyn @22

       Thank you for the time and trouble taken in your three responses. They were both informative and thought provoking.

       I have two points that I think are worth making on your very clear 'walk through' of the likely role of CO2 in increased OHC.

        

       Firstly, a paper published last year by the team at BEST showed that the gap between night and day temperatures has actually been increasing for some twenty five years. I don't have the reference to give you, nor the skills to provide a link if I did, but no doubt it is easily traceable.

       The second point is the possibilty of solar radiation contributing to increased OHC. There seems to be general agreement across the Climate Science Blogosphere that when ENSO is in a 'La Nina', or 'neutral' phase the eastern equatorial pacific ocean and land regions cool due to easterly winds driving surface water westwards and generating an upwelling of cold water in the east. I understamd that the winds that move this mass of upwelling water eastward also create minimal cloud cover, thus exposing the water to high levels of solation on its long journey across the Pacific - over a third of the way around the globe. When this heated water reaches the western extremity of the Pacific, some moves through to the Indian Ocean, some diverts towards the poles, some remains in a pool to fuel the next El Nino and some goes down. As 'neutral' or 'La Nina phases have been dominant this century it seems credible to assume that this process has been a net contributor to OHC.

       If I understand 'Shoyemore' @4 above correctly, the earth receives 1,900 Hiroshima bombs worth of solation per second (Elsewhere I have seen a figure of 1,000). As the process described above is occurring at the equator, a gain in OHC of 4 hiroshima bombs from solation alone doesn't seen too far fetched? - but I'm sure somone cleverer than me can do some sums to see just what the figure could be.

        

       Turning to the question of the thin, cool- skin hypothesis: I agree that if it is flawed it may well be a question of swings and roundabouts as far as OHC is concerned. However, as the mechanisms by which CO2 affects OHC are so completely different in each case, I find it surprising that this issue can even be questioned at this stage (When so much effort and money has been expended on climate science over the last twenty or so years) and in re-reading Rob's article on the layer he references only one paper on the subject.

        

       And so finally to the Roy Spencer paper that I mentioned. I am amazed to read that trends generated by the three bodies processing the same satellite temperature data vary by a factor of three. Someone ought to get them round a table!

        

       Apologies for such a long winded post, but I felt that I owed you the best response that a layman can provide.

44082. Richard Lawson at 02:16 AM on 3 July 2013
       4 Hiroshima bombs worth of heat per second
       

       Some of the heat goes into the melting of Arctic Ice. If we apply gentle heat to a beaker of water containing a lump of ice, the water temperature will not increase until the ice has finished melting. 

       So how much ice has melted?

       The figure here:

       http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/

       shows that the September mean volume for 1979-2012 stands at 12,000 cubic km of ice.
       The September value for 2012 stands at 3,000 cubic km of ice.
       Therefore we have lost 8,000 cubic km of ice, since about 1997.

       1 cubic kilometer of ice = 10^15 grammes of ice

       80 calories of heat are required to melt 1 gramme of ice.

       Therefore to melt 1 cubic km of ice we need 8 * 10^16 calories
       To melt 8000 cubic km ice we need 6.4 * 10 ^ 20 calories

       That is 2.7 * 10^21 Joules which have gone into melting the Arctic ice since 1997.

       This is clearly a lot of heat, but I have no idea how significant it is compared to the earth's energy budget.

       It is 2*10^8 Hiroshima bombs, but how much surface warming would it represent, if, instead of going into melting ice, it went directly into heating the surface air?

44083. danielbacon at 02:16 AM on 3 July 2013
       4 Hiroshima bombs worth of heat per second
       

       Very eloquent!

       IMHO: The rate should be more important. You should say that by 1998. We were at a rate of ~2 Hiroshima bomb detonations per second and since that so called pause we have move to 4 Hiroshima bomb detonations per second. Or put it in step with time. Like in 198x we were at 1 by 199x at 2... and today at 4. How much many more Hiroshima bomb detonations does it need to increase before we start taking this seriously.

44084. johncl at 01:44 AM on 3 July 2013
       4 Hiroshima bombs worth of heat per second
       

       I do believe that many of us convinced in the seriousness of AGW really is trying to figure out how we can explain this to people so they are able to act upon it. Its really one of humanities biggest challenges, one that could have consequences on a planetary scale if not handled in time. Many believe we are really running of out of time. Talking about CO2 emission cuts of a certain % by 2050 isnt going to cut it. What is needed is for people to wake up and understand that our CO2 emissions through our addiction to fossil fuel burning is really turning up the thermostat of the planet causing a shift that the planet likely only have experienced in rather more cataclysmic events like the big siberian traps vulcanism or asteroide impact. The data shows a dramatic concentration of CO2 in both the air and seas at rates 10x past extinction events. I think its really cause for concern even though we dont really see the big consequences right this second. A tipping point can be passed (and most likely several have been passed now with the Arctic melting fast) where the changes happen so fast that global average temperatures could rise rapidly.

       I do believe there is enough evidence now that the planet is absorbing more of the suns energy than it has in the past, and that this amount is significant even on a planetary scale (some are trying to make the 4 abombs per second sound like a small number, just like CO2 is only a small part of the atmosphere - this is a dangerous way of thinking - it only takes 0.25g of arsenic to kill a person). Looking at the broad picture, its really fantastic that life even exists on the planet, and while humans might feel like small gods wielding the power of fossil fuels, we really are quite insignificant and vulnurable, like all living things on this planet. I do believe we should treat our lucky position in this galaxy with some respect and at least acknowledge what we have discovered about simple physics. Sometimes one does not need proof in order to know something is right, if I fall out of a 10 story building, I will likely die - but I dont really need to watch someone fall to their death to understand this is a physical fact. The same way we do know CO2 is a greenhouse gas and that it traps heat. Glenn Tamblyn's line of reasoning perfectly explains a valid reason for the extra heat stored and I my opinion it shouldnt be hard for people to grasp this if they are willing to listen.

       Cheers

44085. Eclectikus at 01:10 AM on 3 July 2013
       4 Hiroshima bombs worth of heat per second
       

       Hi all

       I do not understand this obsession here with "science communicating". Science is not communicated (not as political propaganda), is disseminated and/or popularized, and as far as possible, when it has already passed the rigors of scientific method (empirical validation at least).

       Glenn Tamblyn #24 says "It is a couple of decades too soon to claim that the models are wrong." Yep, However it is not too early to say that the models are correct... I think this is a version of scientific validation quite asymmetric, being naive.

       Last but not less important. Using Hiroshima bomb (more than one hundred thousand dead), gives people an idea of the ethical level, and of the balance between popularize (or explaining) on the one hand, and convince (terrify rather), on this side of debate. From my point of view is a wrong strategy, to the point that it can only work with the more illiterate society. But hey, I'm aware that my opinion is worthless here. It's your choice.

       Sincerely.

44086. John Mason at 00:33 AM on 3 July 2013
       Understanding the long-term carbon-cycle: weathering of rocks - a vitally important carbon-sink
       

       LOL I missed that one when I corrected the others. It was around 0600 this morning when I did the other ones and I hadn't had enough coffee at the time! Sorted now :)

44087. Slioch at 00:06 AM on 3 July 2013
       Understanding the long-term carbon-cycle: weathering of rocks - a vitally important carbon-sink
       

       Another minor typo:

       CaSiO3- (ie showing an overall -1 charge) in equation in top illustration should be simply CaSiO3 (ie with no charge).

44088. DSL at 23:33 PM on 2 July 2013
       It's El Niño
       

       Li et al. 2013 might be a good basis for an intermediate article here:

       
       "Predicting how the El Niño/Southern Oscillation (ENSO) will change with global warming is of enormous importance to society. ENSO exhibits considerable natural variability at interdecadal–centennial timescales5. Instrumental records are too short to determine whether ENSO has changed6 and existing reconstructions are often developed without adequate tropical records. Here we present a seven-century-long ENSO reconstruction based on 2,222 tree-ring chronologies from both the tropics and mid-latitudes in both hemispheres. The inclusion of tropical records enables us to achieve unprecedented accuracy, as attested by high correlations with equatorial Pacific coral and coherent modulation of global teleconnections that are consistent with an independent Northern Hemisphere temperature reconstruction. Our data indicate that ENSO activity in the late twentieth century was anomalously high over the past seven centuries, suggestive of a response to continuing global warming. Climate models disagree on the ENSO response to global warming, suggesting that many models underestimate the sensitivity to radiative perturbations. Illustrating the radiative effect, our reconstruction reveals a robust ENSO response to large tropical eruptions, with anomalous cooling in the east-central tropical Pacific in the year of eruption, followed by anomalous warming one year after. Our observations provide crucial constraints for improving climate models and their future projections."

44089. Glenn Tamblyn at 23:27 PM on 2 July 2013
       Understanding the long-term carbon-cycle: weathering of rocks - a vitally important carbon-sink
       

       chriskoz

       Yeah. This post touches on that, what happened during the Ordovician/Silurian mass extinction.

       The Earth has a basic thermostat. But under the right circumstances it can go haywire. A mass extinction was the result.

44090. John Mason at 23:10 PM on 2 July 2013
       Understanding the long-term carbon-cycle: weathering of rocks - a vitally important carbon-sink
       

       Yes - I'll be writing a piece about that glaciation before too long. It's one of the most interesting episodes of drastic climate change in the geological record, it coincided with the second biggest mass extinction in the fossil record and the rocks around here record its passing. Indeed the relevant stage of the Ordovician - the Hirnantian - is named after a place not that far from where I live!

44091. CBDunkerson at 23:10 PM on 2 July 2013
       4 Hiroshima bombs worth of heat per second
       

       If people don't like Hiroshima bombs you could go with something like 'global energy consumption'. As in, 'global warming is causing the planet to accumulate heat at a rate equal to our monthly global energy consumption every 2 days'.

       Most people probably don't have a good handle on just how much energy we use, but it is one of the few other values in the right ballpark to be a useful comparison point. It would also help to dispel the 'global warming is caused by waste heat' myth.

44092. Tom Dayton at 22:54 PM on 2 July 2013
       4 Hiroshima bombs worth of heat per second
       

       Glenn and Dana, will y'all please add Glenn's comment as a new section in The Big Picture post?  It fills a gap in the logical flow that I've had to fill when pointing people to that post for them to get a very quick basic understanding.  I think it is well worth the tradeoff of making that post slightly longer.  It would be a new section after the section "Global Warming Continues" and before the section "Humans are Increasing Atmospheric Greenhouse Gases."  The section title should be something like "Increased Greenhouse Gases are Causing the Warming."

44093. Terranova at 22:30 PM on 2 July 2013
       4 Hiroshima bombs worth of heat per second
       

       John and Dana:

       After thinking about this some more, I understand that you are using the analogy of 4 Hiroshima bombs per second to represent the amount of heat gained by the earth as a whole.  I don't think it helps the vast majority of even the educated population to understand what is happening.  We all know that an atomic bomb is a bad thing.  But, on a global scale, is it really?  

       When you take the surface area of the earth (5.1×10 8 km 2), and the amount of energy received from the sun: the result is that each square meter of area facing the Sun receives about 1,380 joules per second (otherwise known as the Solar Constant).  Once you look at numbers on this scale, the numbers produced by an atomic bomb (even 4 per second), aren't scary anymore.

       But, everyone knows how bad an atomic bomb is.  So, your use of this analogy is an effective tactic.  

44094. chriskoz at 22:14 PM on 2 July 2013
       Understanding the long-term carbon-cycle: weathering of rocks - a vitally important carbon-sink
       

       Interesting reading John, looking forward to the next in series.

       It's worth adding (I'm not sure if & how well you're going to explain it later) this rock weathering process is also considered to be primary planetary thermostat. That is the balance of the sides of Urey reaction you've shown, is self regulating: e.g. increased rate of rock weathering in response of increased solar forcing, draws down CO2 therfore cooling the planet. The opposite would slow down the weathering, causing CO2 increase from volcanic outgassing, therefore warming the planet.

       Such self-regulating properties of these processes are used to explain the "young sun paradox" - the puzzle why Earth maintained relatively stable surface temp during her 4.6Ga evolution despite sun becoming 30% brighter during that time. The answer: weathering thermostat lowered CO2 levels accordingly. The gradual decline of RCO2 on your last figure in Ga timescale can also be thought as said "thermostat at work", because the sun's intensity has increased signifficantly during that time. You can see for example, that Andean-Saharan glaciation at 460-430Ma happened at CO2 levels relatively high, perhaps higher than during early Cenozoic that enjoyed hothouse conditions. That's because sun's output was weaker at that time so glaciation threshold in CO2 was higher.

44095. Glenn Tamblyn at 21:51 PM on 2 July 2013
       4 Hiroshima bombs worth of heat per second
       

       arncliffe

       Roy Spencer is playing a bit fast and lose with the available data. There are 3 research groups that analyse the data from the satellites. Spencer is one of the principles of one team at UAH. The other teams are at RSS and Star/NESDIS. UAH have been showing a trend of 0.04 C/decade. RSS a trend of 0.078 C/decade. Roy averages these two and shows that average. He doesn't mention Star/NESDIS who are showing a trend of 0.124 C/decade. So if one averaged all 3 satellite results the result would be higher. And in fact it is more accurate to say that the correct value for the satellite data lies somewhere between UAH and Star. If Star is closer to the mark, the models are spot on.

       He doesn't mention that the handling by UAH of the troubled transition between the NOAA satellites NOAA-9 and NOAA 10 has been identified as possibly flawed, leading to a cool bias in the UAH data since then.

       He doesn't mention that the radiosonde datasets are regarded as questionable for climatological purposes at higher altitude due to radiative heating/cooling effects on the instrument packages.

       And then he compares them to model runs based on one of the scenarios with the highest rates of CO2 accumulation.

       Finally he doesn't mention that models don't predict exactly what will happen year by year but rather the broad trends. The models aren't good enough to capture all the causes of short term variability. And if you look at his graph, the data for the sensors still falls within the range of model prediction up to around 1998, 2000. So the models may be missing events over the last decade plus. And this isn't an exceptional result. Shorter term climate variability is harder to model, even when longer term trends can be modelled. And a decade is short term in climate terms.
        It is a couple of decades too soon to claim that the models are wrong.

44096. Glenn Tamblyn at 21:27 PM on 2 July 2013
       4 Hiroshima bombs worth of heat per second
       

       arncliffe

       " I read for example, that downwelling radiation from CO2 acting as a GHG will only heat the top millimetre of the oceans, but that this is sufficient to alter the heat gradient in that skin and reduce ocean heat loss sufficiently to cause the current warming. Is this hypothesis really credible in the real world of turbulent and wind swept oceans?"

       2 scenarios.

       1. The 'skin' absorbs all the infrared downwelling radiation in the first millimeter and this isn't mixed deeper. The thermal gradient in the skin thus restricts heat loss from the bulk of the ocean below. So the visible sunlight that does penetrate through the skin and warms the ocean to depth is restricted from leaving the ocean again.
       2. The 'skin' idea isn't valid. Downwelling radiation is absorbed in the top millimeter but then mixing transfers this heat deeper. And as a result the 'skin' doesn't have a temperature gradient that restricts heat loss from the ocean. So the broader ocean absorbs more heat but is more easily able to lose heat as well.

       Sounds like swings and roundabouts to me, with the same net result.

44097. Glenn Tamblyn at 21:19 PM on 2 July 2013
       4 Hiroshima bombs worth of heat per second
       

       arncliffe

       The full body of evidence that GH gases are causing the warming covers quite a range of subjects. However using a very few pieces of information, just simple observations, we can narrow the field of possible explanations for the warming radically.

       Ocean warming is occuring at around 8 * 10²¹ joules per year, or at a rate of around 253 TeraWatts. So a simple question one can ask is 'Where has this heat come from?'. It must have come from somewhere, the 1^st Law of Thermodynamics demands that. The largest heat source here on Earth is Geothermal heat, heat from within the Earth, is estimated at around 44 TeraWatts. So the heat accumulating in the oceans is occuring around 5.75 times faster than could be caused by the largest terrestrial heat source. So there is an unavoidable conclusion.

       This extra heat isn't coming from anywhere here on Earth. No terrestrial heat source is remotely large enough.

       So those two pieces of data have ruled out all possible 'internal variability' arguments.

       The heating must be being caused by the Earth being in an energy imbalance with Space. Some combination of an increased amount of sunlight being absorbed by the Earth and decreased amount of Infrared Radiation being radiated to Space.

       Next piece of evidence is that the Sun hasn't been warming recently. The Sun has been under virtually constant observation since the mid 70's. Apart from it's normal 11 year cycle, its heat output hasn't been increasing. If anything it has cooled very slightly. So it isn't more sunlight.

       Could it be that more of the sunlight reaching the Earth is being absorbed? Around 30% of the sunlight that reaches the earth is reflected back to space and isn't absorbed. So if that percentage had dropped, perhaps due to less reflective cloud cover or something letting more sunlight through, that would explain things.

       Except there is another piece of evidence that rules that out. If the warming was being caused by anything related to the Sun then we would expect to see more warming when the Sun is shining - during the day and in summer. And we aren't. Temperatures have risen as much if not more during nights and winter. Whatever is warming the Earth operates day and night. And that rules out anything to do with the Sun as a cause.

       This leaves us with only one physically possible conclusion. The Earth is radiating less heat out to space.

       But we know the surface has warmed so the Earth should be radiating more to space, not less!

       So something is blocking more of the Earth's radiation, stopping it from reaching Space. And there is only one thing that can do that. The Greenhouse Effect. The size of the Greenhouse Effect must have increased; that is the only conclusion we can reach from the data.

       Over a decade ago, when the first analyses of Ocean Heat Content were published showing rising heat content, this data was labelled at the time as 'The Smoking Gun'. The gun is still smoking.

44098. Cornelius Breadbasket at 20:34 PM on 2 July 2013
       4 Hiroshima bombs worth of heat per second
       

       EvilDoctorDaddy @ 20

       LIKE :)

44099. EvilDoctorDaddy at 20:26 PM on 2 July 2013
       4 Hiroshima bombs worth of heat per second
       

       Going back to the original point of the the post i.e. “sticky ideas”. When our local vicar wrote a mildly denial article in the parish magazine I invited him around for a solar powered coffee and an explanation of the science of global warming. We finished our session with a look at some of the graphics from here, starting with the escalator and ending with the change in total heat content.

       He asked “how much energy is that?”.

       I said “four Hiroshima size bombs”.

       He said “every year?”.

       I said “every second”.

       His jaw dropped...

       As an idea it’s brilliantly effective.

       BTW, Evil Doctor Daddy is what my kids (3 & 5) call me when I case them around the house...

44100. arncliffe at 19:12 PM on 2 July 2013
       4 Hiroshima bombs worth of heat per second
       

       Tom Curtis:

       Thanks for your reply, I will read your recommended link with interest. Although my main interest in writing to SKS was the rising OHC issue, your comments on the atmospheric temperature 'pause' were interesting but also highlight a problem I have found in gaining an understanding of climate science: There is now an absolute plethora of both models and data sets and these tend to create a 'pick and mix' facility that can seemingly be used to support or rebut any argument. For example, Dr Roy Spencer has recently published on his site a graph that I haven't seen rebutted anywhere, showing the same models as yours, but plotting the satellite/balloon temperatures of the 'tropical mid troposphere', which currently fall well outside the predictions of any of the models.

       scaddenp:

       I read as widely as I can, but my questions on rising OHC and the thin cool-skin layer were prompted solely by the above article and earlier ones by Rob Painting and Dana.

       Chris G:

       In answer the last, offensive, paragraph, I did not say that 'it is necessary for IR to penetrate to a depth in order for depth to be heated' or anything remotely like it. I simply referred to the the thin cool- skin effect mentioned by Rob Painting in his article last week, in which he postulated that it inhibited loss of OHC to the atmosphere.

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