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Comments 79351 to 79400:

79351. Composer99 at 06:57 AM on 16 July 2011
       OA not OK part 6: Always take the weathering
       So calcification releases CO₂ into the ocean (and eventually the atmosphere), while weathering removes CO₂ from the atmosphere and eventually deposits it into the oceans. I assume these two processes occur at dissimilar rates, since volcanism also releases CO₂ into the atmosphere, and the volcano-weathering interaction is Richard Alley's famous CO₂ thermostat.
79352. Bibliovermis at 06:53 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Eric the Red, The goalpost has now been moved into the straw field. One's subtlety is another's well known & understood physical effect. Yes, the solar cycle does affect the climate. Using a 5 year moving average, the hottest 30 5-year-periods are the past 30; 1941-1945 is #31. The average rate of change over those 30 periods is +1.7. The last 10 periods have been the Top Ten; 1996-2000 is #12. Period Endpoint: Anomaly (change) 2007: 55.7 (+0.4) 2010: 55.5 (+0.1) 2009: 55.4 (+2.0) 2006: 55.3 (+1.5) 2005: 53.8 (+5.9) 2008: 53.4 (-2.3) 2004: 47.9 (+3.2) 2002: 44.9 (+3.4) 2003: 44.7 (-0.2) 2001: 41.5 (+3.8) 5 of those top ten had an above average change.
79353. Composer99 at 06:17 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Rob @ 48: Thanks for the clarification. I suspect I made an error of granularity regarding decadal anomaly vs annual.
79354. JosHagelaars at 04:11 AM on 16 July 2011
       OA not OK part 6: Always take the weathering
       It turns out that amount of weathering is sufficient to remove all CO2 from the atmosphere in 3500 years. Faster than I expected given the amount of carbon in the atmosphere. Do you have a reference or a link regarding this calculation, so I could read more about it ? Is the Urey reaction treated in another post ? Thanks in advance.
79355. Chris G at 04:02 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Regarding Manktelow (2009), I would guess that there would be obfuscation of differences by latitude. Not only would circulation patterns, including Hadley cells, create differences in the altitudes reached by the particles, where aerosols in the the lower lats reach higher altitudes and have longer residence time, but lower latitudes receive more watts per square meter than higher latitudes.
79356. Eric the Red at 03:43 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Bibliovermis, See Rob's plot of the 5-year moving average. All the subtleties are lost on longer term averaging. The recent flattening may just be a repeat of the previous three.
79357. Chris G at 03:36 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       I wish I had more to add, but almost all my thoughts have been covered by others. Sphaerica, FTIW, I share your fear at #16. If you view all the decade or less ups and downs as short-term deviations from a mean caused by short-term drivers, and the mean is moving upward, driven by the longer term increase in CO2, (A bit more than linearly, Eric, as has been discussed before, Monckton Myth #3: Linear Warming.), then, yes, once the short-term drivers have subsided, there will be a spike to return to the mean. Though, I've all but given up on any turn of events, like repeated record losses of Arctic ice, serving as a wake-up call or stunning skeptics into accepting the reality of our situation.
79358. Eric the Red at 03:32 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Rob, The effect of the solar cycle becomes quite evident with sunspot minima occurring aroudn 1976, 1986, and 1996. The recent minimum will not become apparent until warming resumes. Longer term effects would not be so evident on this time scale.
       Response:

       [DB] "until warming resumes"

       Resumes from what?  Some mythical slowdown?  Perhaps you missed the warmest decade in the instrumental record, as Bibliovermis has kindly pointed out.  Or 2010 being the warmest in the GISS record, followed closely by 2009.  Or 2005.  Yadayadayada.

       Your narrative of cooling/no warming conveniently lacks any tie-in with reality.  But I do give you kudos for determination to not stray from your agenda.

79359. Bibliovermis at 03:26 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Eric the Red, Using a 10 year moving average, the hottest 28 decade-periods are the past 28; 1937-1946 is #29. The average rate of change over those 28 periods is +1.8. The last 10 years have been the Top Ten, in sequential order except for 2008. Period Endpoint: Anomaly (change) 2010: 54.6 (+3.0) 2009: 51.6 (+2.6) 2007: 50.3 (+1.9) 2008: 49.0 (-1.3) 2006: 48.4 (+2.6) 2005: 45.8 (+2.5) 2004: 43.2 (+2.4) 2003: 40.8 (+4.2) 2002: 36.6 (+4.4) 2001: 32.3 (+1.3) 8 of those top 10 had an above average change. How is that a slowdown?
79360. Rob Painting at 03:15 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Composer99 @ 44 - "Bibliovermis' post @40 shows that when you include the poles, warming is continuing largely unabated (per GISS)" 5 year running mean for the GISTEMP data. No dispute over long-term global warming, but shorter timescales are another matter. Even James Hansen, the head of NASA GISS, claims radiative forcing has declined in the last decade. See figure 1 in his paper Earth's Energy Imbalance and Implications
79361. Eric the Red at 03:08 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       THank you Tom, It appears that we think alike (sometimes). The moving average better shows the large increase that occurred in the 1990s and the slower increase of the 2000s. While I agree with Tamino that ENSO, solar, and aerosols have influenced temperatures of the past few decades, I am not comfortable endorsing his "adjusted temperatures" yet. A few reasons. First, I do not believe that they can be applied uniformly to each database, and secondly, additional work is definitely needed to firm up his corrections for each parameter. That said, I tend to agree that there has been a rather linear temperature increase since the late 19th century, which would probably become evident applying the above listed adjustments to the datasets. Although this will not end the discussion about natural variations, it will go a long way towards incorporating both natural and anthropogenic forces into the equation.
79362. Tom Curtis at 01:57 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Bibliovermis @40, I'm sure Eric the Red would want to point out that a running mean is a more accurate indicator. An 11 year running mean of GISStemp increases Using an 11 year running mean, the GISS temperature increases in every year since 1987, but the three years with the highest increases are 1998 (0.038 degrees C), 2000 (0.036) and 1999 (0.032). Comparing decadal means is approximately equivalent to comparing the decadal difference in the running mean for the middle year of each decade, and yields a suitably stark number. But it does not alter the fact that the peak rate of change of GISStemp global index was the late 1990's, and that it flattened to almost zero in 2004, before picking up to 0.028 degrees C (the fourth highest value in the last 50 years). The reason for that is interesting, and prior to 2008 I would have said it was almost entirely an artifact of the very high temperature in during 1997/8 El Nino. However, 2008 was a very cold year for the 2000's, and some additional explanation is called for. However, the combination of Asian industrial aerosols, ENSO and solar minimum seems more than adequate as an explanation. These factors undoubtedly had an effect. Causation does not simply cease to allow us to invoke alternative explanations (or oscillations). The question is whether additional explanation is needed. The fact that when Tamino adjusted five temperature series for ENSO, volcanic sulfates, and the solar cycle, he has such small residuals strongly suggests that no long term cycle is influencing temperatures. In particular, had such a cycle peaked circa 2005, we would expect a strong down turn in the adjusted temperatures, and no such down turn exists: As Tamino says:

       "Another interesting point is that in the adjusted data sets, all 5 sources have 2010 as the hottest year on record. In fact, 4 out of 5 (all but NCDC) also have 2009 as the 2nd-hottest year — quite the 1-2 punch. Of course all trends are statistically significant — strongly so. The conclusion is inescapable: the globe is warming, and shows absolutely no sign whatever of stopping or even slowing its warming. Any talk of “cooling” or even a “levelling off” of global warming over the last decade is absolute nonsense."

       The apparent levelling of in the rate of temperature growth in GISS figures is purely noise due to the interplay of a strong El Nino and declining aerosol levels in 1997/8, and a strong La Nina, increasing aerosol levels and a solar minimum that almost recorded lower activity than that of 1910(?) in 2008.
79363. Albatross at 01:47 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       With reference to Hansen et al. (2010) and GISTEMP. Below is the 132-month running mean (same as in their Fig. 21 except including data until May 2011): [Source: woodfortrees.org] Kaufmann et al. (2011) were interested in the possible causes of that small plateau in the green trace early in the 21st century. Interestingly, Koch et al. (2011) have just published paper on the radiative forcing of aerosols and found that the net direct forcing of aerosols is -0.41 W m-2. They also note that: "To test the climate responses to sulfate and BC pollution, two experiments were branched from 1970 that removed all pollution sulfate or BC. Averaged over 1970-2000, the respective radiative forcings relative to the full experiment were +0.3 and -0.3 W m-2; the average surface air temperature changes were +0.2° and -0.03°C. The small impact of BC reduction on surface temperature resulted from reduced stability and loss of low-level clouds." Koch et al's value is very close to the median value for direct aerosol forcing reported in the IPCC's 2007 report.
79364. Composer99 at 01:45 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Given that the Hadley temps omit polar data, would it not be the case that an apparent slow-down in warming when reviewing the Hadley temperature record is simply an artifact of this omission? Bibliovermis' post @40 shows that when you include the poles, warming is continuing largely unabated (per GISS). Or is it the case that warming was expected to be even more severe in the late 'noughts, and papers like Kaufman 2011 are attempting to account for the less-than-expected severity?
79365. KR at 01:44 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Eric the Red Selecting your analysis to fit your hypothesis is an odd form of Inductive Logic (as defined in the 1986 classic Science Made Stupid): Cherry picking, and not a good approach. Your analysis method should be driven by proper statistics, not best-fitting to a conclusion. --- "Once, when the secrets of science were the jealously guarded property of a small priesthood, the common man had no hope of mastering their arcane complexities. Years of study in musty classrooms were prerequisite to obtaining even a dim, incoherent knowledge of science. Today, all that has changed: a dim, incoherent knowledge of science is available to anyone... Indeed, today a myriad of sources are available to explain science facts that science itself has never dreamed of." SmS 2986
79366. guinganbresil at 01:33 AM on 16 July 2011
       Trenberth on Tracking Earth’s energy: A key to climate variability and change
       Ken Lambert #60 I apologize if I misunderstood you - I thought you were comparing the clear sky EBAF plot in figure 3 (at ~ 1 W/m²) to the total energy imbalance which is estimated by models to be 0.9 W/m² I have noticed that there is an abundance of Fallacy of Composition regarding energy balance, and emission spectra: - Just because the emission to space at the CO2 band of the spectrum (left hand side of figure below at ~600-700 cm^-1) goes down does not mean the the total emission to space goes down.
       Figure: Observed difference between 1970 to 1996 over the central Pacific (top). Simulated difference over the central Pacific (middle). Observed difference for 'near-global' - 60°N to 60°S (bottom) (Harries 2001). - Just because the emission to space from clear skies goes down does not mean that the total emission to space goes down. The figure above shows only clear skies... We need to be precise about this...
       Response:

       [DB] Fixed unclosed italic tag.

79367. Eric the Red at 01:25 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Bibliovermas, Instead of calculating based on 10-year averages, why not use a moving average? Since the 5-yr moving average turning poistive in 1978, it has show large and small rise roughly in line with the solar cycle. The largest increase was in 2003, and it has been declining since. It may be nothing more than a response to the changing sun, similar to previous sunspot lows. Using a decadal average, you are showing the increase that occurred in the previous decade, the 1990s, not the 2000s.
       Moderator Response: [Dikran Marsupial] Choosing the form of analysis to get the result you are looking for is a form of cherry picking. Decide what form of analysis is required before looking at the details of the data.
79368. Tom Curtis at 01:16 AM on 16 July 2011
       It's the sun
       Eric (skeptic) @869, we do not need to determine the change in incoming energy from a solar minimum by plotting atmospheric temperatures. We can, and do, measure it directly. Consequently we can come to conclusions about its effects on atmospheric temperatures, although the uncertainties are large.
79369. Composer99 at 01:11 AM on 16 July 2011
       Monckton at odds with the very scientists he cites
       I agree with rpauli to some extent. Certainly, there is no need to be rude or offensive when speaking of people actively trying to prevent policy action on climate change, people such as Monckton. However, there is no reason not to be forthright. The evidence suggests he is engaging in systematic, deliberate misrepresentation of climate science, and if he is not ignored then it is sensible to call him out on it.
79370. Leland Palmer at 01:08 AM on 16 July 2011
       Thinning on top and bulging at the waist: symptoms of an ailing planet
       I've wondered about this movement of mass from the poles to the equator, and due to conservation of angular momentum, it seems likely that the rotation of the earth will slow, somewhat. More importantly, though, how will the stresses due to conservation of angular momentum be transmitted from the oceans and crust to the mantle and core? Could we be triggering a geomagnetic reversal, changing the relative rotation rates of the mantle and core? Googling around, I found this old paper by Berkeley's controversial Richard Muller, unfortunately hidden behind a pay wall: http://www.agu.org/pubs/crossref/1986/GL013i011p01177.shtml

       The impact of a large extraterrestrial object on the Earth can produce a geomagnetic reversal through the following mechanism: dust from the impact crater and soot from fires trigger a climate change and the beginning of a little ice age. The redistribution of water near the equator to ice at high latitudes alters the rotation rate of the crust and mantle of the Earth. If the sea‐level change is sufficiently large (>10 meters) and rapid (in a few hundred years), then the velocity shear in the liquid core disrupts the convective cells that drive the dynamo. The new convective cells that subsequently form distort and tangle the previous field, reducing the dipole component near to zero while increasing the energy in multipole components. Eventually a dipole is rebuilt by dynamo action, and the event is seen either as a geomagnetic reversal or as an excursion.

       What we're doing by AGW is rapidly shifting mass from the poles to the equator, the opposite of Muller's hypothesis, which shifts mass rapidly from the equatorial regions to the poles. But the geomagnetic disruption due to conservation of angular momentum may be the same in each case.
79371. Rob Honeycutt at 01:05 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Sphaerica @ 39... I was just over in China and the news there is saying that the central government has already been fairly aggressively shutting down older plants who have not put in pollution controls. Apparently the government gives out notice to upgrade or be shut down. Then when the upgrades don't happen they just go in and board the place up.
79372. Bibliovermis at 00:54 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Eric the Red, Rather than eyeballing a few pixels, crunch the numbers. GISS: Global-mean Combined Land-Surface Air and Sea-Surface Water Temperature Anomalies dataset The GISS Surface Temperature Analysis (GISTEMP) main page has a discussion on the usage of temperature anomalies versus absolute temperatures. Decade: Anomaly (change) 2000s: 51.6 (+20.3) 1990s: 31.3 (+13.8) 1980s: 17.5 (+17.5) 1970s: -0.1 The 2000s were warmer than the 1990s by a larger margin than the 1990s were warmer than the 1980s. It was also the largest decadal change on record. How is that a slowdown? Here is the rest of the crunched dataset for comparison. 1960: -1.4 1950: -2.0 1940: 3.6 1930: -4.2 1920: -17.6 1910: -27.6 1900: -26.1 1890: -25.6 1880: -27.3
79373. Eric (skeptic) at 00:42 AM on 16 July 2011
       It's the sun
       correction: should say "-2.1" for the 1989 number
79374. Eric (skeptic) at 00:41 AM on 16 July 2011
       It's the sun
       Tom, AGW is real and shown by La Nina in 1989 producing -.21 on UAH and La Nina in 2008 producing -0.3 or so (from the graph of 13 month running average). But that is not the point. The solar minimum being advanced as a theory for cooling in the other thread(s) is already part of the La Nina SST measurement (the drop in solar energy has lowered that measurement) so there is no coincidence of various factors (excluding the aerosols discussed on the other thread) There is simply energy and we have no really precise way to measure how much the energy of the earth changed due to those factors (and others). Simply put, by measuring the atmosphere we can make no conclusions about the effects or lack thereof of the solar minimum, especially in such a short period of time.
79375. Tom Curtis at 00:09 AM on 16 July 2011
       It's the sun
       Eric @867, I am unsure why you are arguing this point. Yes, a solar minimum coincident with a strong El Nino will result in a warm year, but not as warm as a strong El Nino coincident with a solar maximum. More importantly, a solar minimum coincident with a La Nina, as occurred in 2008, will result in a cooler year than an equivalently strong La Nina by itself. If the solar minimum and La Nina also coincide with increasing sulphate concentrations, either due to a large tropical volcano or industrial emissions, it will be cooler still. 2008 happened to coincide with all three, yet was still the 12th warmest year on record, and warmer than any year prior to 1997 on the instrumental record going back to 1850 (hadcrut3 global). That also means there is a significant probability that it was warmer than any year in the MWP. According to Mark Twain's famous definition, climate is what you expect, and based on our expectations (and denier descriptions), 2008 was a cold year a. When the 12th coldest year in (probably) over a thousand years is cold according to our expectations, our expectations have changed significantly. That is climate change, and GHG emissions is the only explanation that makes any sense.
79376. Bob Lacatena at 00:00 AM on 16 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Rob Painting... do you have an answer to my question at 16?
79377. Eric (skeptic) at 23:47 PM on 15 July 2011
       It's the sun
       Ugh, my comment in 859 "unlike changes in GHGs which mostly melt ice" is wrong. See figure 3, the model results in part 4 of science of doom (please follow link above since the part 4 link is squirrely). Specifically, the heating of the ocean from changes in GHG (downward LW changes) is no different from changes in solar radiation despite the latter's deeper penetration. Now that I've corrected that tangent, please realize that my original point remains intact which is that the small TSI drop from the recent solar minimum can be easily outweighed by ENSO. That means the solar minimum does not necessarily translate to the atmosphere.
79378. Eric the Red at 23:45 PM on 15 July 2011
       It's Pacific Decadal Oscillation
       Here is a link to some recent work about the contribution of decadal oscillations to the observe global temperature rise. http://www.springerlink.com/content/akh241460p342708/
79379. Eric (skeptic) at 23:23 PM on 15 July 2011
       It's the sun
       My #865 seems to be contradicted by this: http://scienceofdoom.com/2010/10/06/does-back-radiation-heat-the-ocean-part-one/ and follow-on threads. It's going to take me a while to read through these.
79380. Ken Lambert at 23:21 PM on 15 July 2011
       Trenberth on Tracking Earth’s energy: A key to climate variability and change
       guinganbresil #59 So what is the conclusion from this? What relevance has Fig 3?
79381. Eric (skeptic) at 22:58 PM on 15 July 2011
       It's the sun
       skywatcher, there are probably threads that explain why GHG energy (LW) doesn't preferentially enter the ocean, but I'll have to look around.
79382. Eric the Red at 22:55 PM on 15 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Michael, Not sure why you think that GISS does not show the same slowdown as the others. Looking at the graphs for global temperature, the last decade has not shown the same rise as the previous two. Of course, one could argue that the temperature moves in jumps rather than continuous increases as witnessed near the start of the past three decades. IF that is the case, then the recent stabilization is just a consolidation before the next upswing. http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.gif http://data.giss.nasa.gov/gistemp/graphs/Fig.C.gif
       Response:

       [DB] Those believing in physical reasons underlying the GISS temperature changes rather than climastrology should take heed of this Tamino analysis, wherein he examines the GISS temperature record through 2010.  Removing the exgenous effects like El Nino, volcanic effects and annual cycles yields this:

       

       No "stabilization" evident.  In fact, 2010 was the hottest year in the temperature record (despite a "perfect storm" of low TSI, a strong La Nina and high aerosol emissions) followed closely by (drumroll please, maestro)...

        

        

        

       ...2009.

        

        

       Of course, one could argue for the need to keep an "Open Mind" about things, but predilections for mystical "cycles" neccessitate one's brain possibly falling out said open mind.

       And that benefits no one.

79383. Eric (skeptic) at 22:54 PM on 15 July 2011
       It's the sun
       skywatcher: the statement "The global-scale solar forcing is perfectly real, but small, and has indeed hindered temperatures over the past decade." is not supportable. Here is a supportable statement: "the small but real change in solar forcing has lowered the energy of the earth system by a small amount. That loss of energy may or may not manifest in lowered atmospheric temperatures since other ocean-related factors such as ENSO are much larger than the ocean-related solar heating/cooling."
79384. skywatcher at 22:52 PM on 15 July 2011
       It's the sun
       Eric, you're barking up a very wrong tree in your last three posts as well - as KR states, GHG's most certainly do not just 'mostly melt ice' - why would enhanced GHGs not impact temperatures at midlatitudes or tropics, therefore warming the oceans? If solar energy penetrates the oceans, the variations also penetrate the oceans, regardless of whether ENSO variations temporarily mask those variations. GHG-driven forcings also enter the oceans. Weather pattern changes may also be GHG-driven (creates stratospheric cooling...), and sea ice reduction-driven (altering surface evaporation, temperature and pressure patterns). Do you have any evidence for your assertions?
79385. skywatcher at 22:44 PM on 15 July 2011
       It's the sun
       Eric S, why would that apply to me? If you're meaning my post on the thread you link to in #858, my comments were in relation to Tamino's filtering out of 'exogenous factors', in his post How Fast is the Earth Warming?. Since 1998, we have gone from very strong El Nino forcing to a very strong La Nina forcing, and from a solar max to a solar min. Tamino has quantified the adjustments to the timeseries driven by each of these exogenous factors, and for RSS, he estimates solar forcing to have dropped 0.1C of temperature equivalent over the decade for RSS, 0.05C for GISS. Larger forcings (range of up to +0.4/-0.2) are attributable to ENSO, which is right in line with my previous understanding of the forcings. The global-scale solar forcing is perfectly real, but small, and has indeed hindered temperatures over the past decade. It is interesting to note that the 2000s were even hotter than expected on a decadal scale, given the decadal increases from the 1970s, 1980s and 1990s. It's just that relatively speaking the earlier years of the 2000s were hotter and the later years were 'cooler'.
79386. Eric (skeptic) at 22:44 PM on 15 July 2011
       It's the sun
       KR, do we really need a reference for this? The planet is 72% ocean and weighted more towards low latitudes where the sun is more direct. The highest energy portion of the solar spectrum, about 1 micron and less, are able to penetrate deeper and heat deeper. A lowering of ocean heating due to slightly lower TSI can be easily outweighed by an increase in SST due to the phenomenon like ENSO (warming from less wind, fewer clouds, etc). Thus solar minima are easily outweighed by other factors.
79387. Paul D at 22:42 PM on 15 July 2011
       Visions of the Arctic
       There's an exhibition called High Arctic at the National Maritime Museum (UK) about the receding Arctic ice: http://www.nmm.ac.uk//visit/exhibitions/on-display/high-arctic/
79388. KR at 22:31 PM on 15 July 2011
       It's the sun
       Eric (skeptic) - "Specifically, any change in TSI is applied directly to the oceans, unlike changes in GHGs which mostly melt ice. All other solar changes change the weather which may create temporary warming or cooling." Eric, this is so far off that it's close to being not even wrong. Changes in radiative forcing from TSI or from GHG's have slightly different distributions (particularly in the stratosphere), but all radiative forcings affect the oceans, the ice caps, and the weather. Unless you have a reference or two to support this, I would have to consider your last post or two simply unsupportable.
79389. michael sweet at 22:28 PM on 15 July 2011
       Why Wasn't The Hottest Decade Hotter?
       As Icarus pointed out at 6 in this blog, if we use the GISSTEMP record the warming continues unabated. The deniers use HADCRU (which they say is discredited by e-mails) because it does not show all the global warming. I think the lead article should have made a strong point that it is only when you use HADCRU that you find warming slowed. HADCRU is well known to underestimate global warming over the past decade due to lack of Arctic coverage. It is better to use GISS because GISS more accurately reflects what is happening around the globe. Using GISS we find that global warming did not slow during the 00's. Hansen agrees with Kaufman that sulfate aerosols mask a lot of warming. The Faustian bargain will soon come due. When sulfate pollution is controlled the temperature will rise even faster than it currently is rising.
79390. Eric (skeptic) at 22:22 PM on 15 July 2011
       It's the sun
       skywatcher, my previous post on this thread applies to you as well. The "solar minimum" is not an adequate explanation of why the 2000's were not hotter. Specifically, any change in TSI is applied directly to the oceans, unlike changes in GHGs which mostly melt ice. All other solar changes change the weather which may create temporary warming or cooling. The solar to ocean connection is direct: the sun heats the ocean. A drop in solar TSI due to the "solar minimum" can easily be offset (or "masked") by a relatively small amount of SST warming, the best example being El Nino. Thus, solar mimima do not automatically create atmospheric temperature drops.
79391. skywatcher at 22:04 PM on 15 July 2011
       Why Wasn't The Hottest Decade Hotter?
       on cycles, this paper by Vincze and Janosi may be of interest. They discuss the effect of smoothing on identifying the 'AMO', and suggest that the 'O' of AMO should be replaced by a 'V' for Variation. Similar to Tamino's articles about people who find 'cycles' in data where the period of the proposed 'cycle' is large in relation to the total time period under study. Just because you think you find a 'cycle' rather than an apparent variation that is vaguely coincident does not take you any closer to a physical driver of the climate system. As mentioned before (#14 and Dikran above) there is no underlying physical energy transfer mechanism for the PDO, and perhaps the best explanation is an integral result of the events of ENSO. As there is no clear means for PDO to add or remove significant energy from the climate system, why do people hold on to it for an explanation of climate changes? Far more plausible, and with energy flows and physical mechanisms understood in support, are variations in aerosols largely causing the 1960s cooler episode. Given Tamino's analyses (#5), and the data from global analyses such as GISS, and of course the ever-present internal variability of the climate signal, I suspect the 'hiatus', if it even significantly exists, is one already explained by existing climate drivers, the consequence of which will be renewed rapid warming soon. If there really is an aerosol signal, in the last few years of data, then it suggests a scary future, as the other key exogenous factors (esp ENSO, solar) already do a good job of explaining the 2000's.
       Moderator Response: (Rob P) The PDO is off-topic. Further comments should be made on the relevant thread.
79392. Eric the Red at 22:00 PM on 15 July 2011
       It's Pacific Decadal Oscillation
       Barry, I have done some work looking at the linear vs. oscillatory trends. Two cylces have been observed with a period of just under 61 years and an amplitudes of 0.3C. When this is subtracted from the temperature data (CRU), a linear increase of 0.6C / century remains. Should these two trends continue, global temperatures would bottom out again at around 2033 at ~0.1C below current levels, before rising again. The strong La Nina has definitely been an influence as temperatures for 2011 have been below the combined trendline for five of the first six months of 2011. Scaddenp may be correct in that the PDO is just a long term index related to ENSO.
79393. Eric (skeptic) at 21:55 PM on 15 July 2011
       It's the sun
       In this post /news.php?n=868#58115 Tom Curtis partially attributes cooling since 2008 to an exceptionally low solar minimum. But he effects of a solar minimum are vastly more complex than "cooling". Just two examples, the drop in solar UV (much greater %-age than TSI) creates stratospheric cooling which becomes uneven and creates blocking patterns. Those blocking patterns may induce heat waves or other extreme weather, perhaps generally globally cooling, but not simple. Another factor is high GCR which may produce more low clouds which may also be cooling or perhaps not. The other consideration for Tom is that solar effects, even the simplistic drop in TSI, are subject to the same thermal inertia as AGW (if not more). For example the entirety of lowered TSI could easily be "masked" from appearing in the GAT by a rise in SST (e.g. from El Nino). In that case (I'm not saying that happened recently or not), the solar minimum essentially only causes an OHC drop.
79394. Dikran Marsupial at 21:52 PM on 15 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Eric the Red there has not been a large on-going debate as to whether PDO is the cause of the observed warming, except in the blogsphere. You need a physical mechanism that can explain the strenght of the effect, not just a correllation before scientists will take a theory seriously (because corellation is not causation). There is plenty of discussion in the blogs, but that is largely a reflection of the relative quality of science in the journals and in the blogs concerned. "three would be telling" is statistically nonsensical. In the absence of a competing explanation, then three cycles in a dataset would be taken as good evidence for a periodic structure. However in this case there is a competing theory and you would need to revise physics to explain why CO2 and aerosols and solar forcing were not having their expected effect.
79395. Eric the Red at 21:36 PM on 15 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Hyperactive Hydrologist, Whether the two warming periods being similar is a coincidence or not has been a subject of a large, on-going debate. The bigger question concerns the intervening cooling period, and the most recent decade. As mentioned previously, one thought is that aerosols arising from two different sources have generated the slowdown in both cases. An alternative has been the PDO cycle. Both are plausible, but may only be part of the answer. If the answer is aerosols, that would argue for a climate sensitivity on the higher side, whereas the PDO would place it on the lower side. Two 60-year cycles could be a coincidence. Three would be telling.
79396. Eric (skeptic) at 21:23 PM on 15 July 2011
       It's Pacific Decadal Oscillation
       barry, thanks for explaining the distinction between the centenial (mostly secular) and decadal (mostly oscillatory) trends. I believe most of the fluctuation in the secular AGW trend can be explained with natural oscillations. There do not seem to be very strong long term natural trends at the moment. Specifically warming accelerated in the 80's and 90's and decelerated in the 00's. I can also answer my question from January, the La Nina was strong, especially in its effects on the continental US stemming from abnormally cold Pacific temperatures. Those effects still linger, but the La Nina has ended. However it is predicted to return, not good news for drought-stricken Texas and rain-soaked Montana.
79397. skywatcher at 20:58 PM on 15 July 2011
       Websites for Watching the Arctic Sea Ice Melt
       Arctic ice sea melt looks like being interesting/scary this year. 2011 is currently (14th July) the lowest extent of all years in IJIS, NSIDC, Uni Bremen and DMI graphs for the current date. It's lower even than the record-breaking 2007, even though we're getting through the period where 2007's extent reduced very rapidly. 2011 is currently 265625 sq km below 2007 (IJIS), and over half a million sq km below last year, which itself is the 3rd lowest extent for 14th July. The odds of a new record low extent have just shortened somewhat, but will it be enough to wake people up to what is happening? The canary is struggling for breath...
79398. Dikran Marsupial at 20:34 PM on 15 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Hyperactive Hydrologist If it did, it would only be masking the warming due to the additional CO2 emissions, and when the aerosol emissions end, they are quickly removed from the atmosphere (unlike the CO2) and the enhanced greenhouse effect would rapidly reassert itself again in a big way. Of course we all want the standard of living in the third world to improve with time (at least I would hope we all want that); however in order to achieve that without making our global environmental problems even worse, we need to reduce our emissions in the first world. However that is a topic for a different thread.
79399. Hyperactive Hydrologist at 20:33 PM on 15 July 2011
       Climate Change Impacts on California Water Resources
       I did a project on the Colorado basin recently. Major issues are due to demand. Some of my conclusions. • The initial apportionment of water under the Colorado River Compact was based on data collected over a short period, at a time of relatively high flow. Current water balance suggests that the sum of the entitlements is higher than current flows. • No consideration was taken for environmental needs within the Compact as a result discharge to the Gulf of California is close to zero. • Pollution is a major problem, partly due to very low river flow, with high salinity of river water especially in the southern reaches. Desalination plants at the Mexican border reduce the salinity of the river water before it enters Mexico. • There is no organisation which has overall control over the basin. • Agricultural use of water has grown rapidly over the last century and accounts for 80% of the water used. • Many of the crops grown in the basin are exported to other regions or countries for example exporting hay and rice to Japan. • Huge subsidies on water prices are allowing farmers to grow crops which would otherwise not be economically viable. • Rapid population growth has increased water demand substantially. The population grew by 10-35% between 2000 and 2010 in the 7 states within the Colorado basin. This growth is expected to continue. • Population growth is, in part, indirectly driven by cheap water prices. • Residential water usage is amongst the highest in the United States, however, water prices are some of the lowest. • Much of the Infrastructure in Colorado basin is funded partly by the federal government. The United States collectively is paying for infrastructure • Open water evaporation from reservoirs is a major problem, with losses estimated to be approximately 2MAFY. • Climate Change will increase temperatures in the Colorado basin by 2-4°C. Reduced run off will decrease flows in the Colorado River by 10-30%. By tackling some of the issues with demand and getting rid of subsidies on water prices many of the issues could be dealt with relatively easily. For instance increasing block tarrifs need to be employed. Also the actual cost of water needs to be evaluated including the payments for existing infrastructure.
79400. Hyperactive Hydrologist at 20:16 PM on 15 July 2011
       Why Wasn't The Hottest Decade Hotter?
       Broken link? Indian Coal Rush

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