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ubrew12 at 05:43 AM on 10 December 2014California just had its worst drought in over 1200 years, as temperatures and risks rise
In the first graph, above, the variability strongly suggests that most of the current drought is natural. However, I was struck by the average value. It indicates that drought became slightly less severe from 800 AD to 1880 AD, after which it abruptly changed its trend, and became rapidly more severe throughout the last century. An abrupt trendline reversal at 1880 AD is also seen in global temperature.
Correlation is not causation, but its hard not to ignore the average trendlines of CA PDSI and global temperature, both abruptly changing direction around 1880.
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william11409 at 03:45 AM on 10 December 2014California just had its worst drought in over 1200 years, as temperatures and risks rise
Thanks Dana. Yes the comment from Prof Mann mentioned in Will@3 was present in the article I linked to as was a comment by Kevin Trenberth "This study completely fails to consider what climate change is doing to water in California,". As both are well respected climate scientists I guess NOAA will address their comments in due course.
I note you consider "NOAA is doing the public a disservice by claiming otherwise". while the Moderator's opinion is "What you are observing is the scientific process at work. Over time, the seeming contradictions will be sorted out. This sifting and winnowing process occurs in all scientific disciplines". So is the sifting and winnowing a disservice to the public or just a necessary part of the scientific process?
He also berates me for suggesting " that conflicting explanations are unique to climate science is bogus". Actually ` didn't suggest that at all if I had meant to make that suggestion I would have written "in contrast to other branches of science only in climate science are two opposing explanations are put foward for the same event" That would clearly be utterly incorrect.
Moderator Response:[JH] You are skating on this thin ice of moderation complaint. Please read and adhere to the SkS Comments Policy.
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dana1981 at 01:58 AM on 10 December 2014California just had its worst drought in over 1200 years, as temperatures and risks rise
william @1, see wili @3. The NOAA report is flawed in its failure to consider the drought influence from human-caused warming, as I discuss above. The human influence on CA precipitation is a mixed bag, with 2 studies finding no connection and 2 finding a connection. NOAA focused on the former 2 (having authored one of them), but frankly I find the other two (Diffenbaugh and Wang) more convincing.
Nevertheless, there is indisputably a human influence on the drought due to warming. NOAA is doing the public a disservice by claiming otherwise.
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CBDunkerson at 23:46 PM on 9 December 2014Even climate change experts and activists might be in denial
One Planet, it isn't that simple.
You say, "...common sense is all that is required to recognise that the consumption of non-renewable resources needs to be curtailed from human activity...".
Sure, that makes sense... except that consumption of those non-renewable resources may eventually be replaced by renewable options that wouldn't have been possible without the advancements made using the non-renewables. If we had curtailed use of coal we wouldn't have had the abundant cheap electricity which allowed a mass computing environment... which led to the development of solar and wind power cheap enough to now begin replacing the coal.
Ditto, "Every very fortunate person should be required to behave far better, stop trying to benefit from the burning of the stuff...". Again, that seems 'fair'... except that those fortunate people, by virtue of their better resources, education, stability, et cetera have the ability to develop new technologies which then in turn greatly benefit the less fortunate people. Look at what solar PV, previously a toy only affordable by the rich, is now doing in remote areas of India, Africa, Australia, and other places that never had electricity before.
Personally, I don't see the 'conflict' over global warming policy as between 'populations of countries with high standards of living vs those with low standards of living' at all. At this point, it should be clear that moving away from fossil fuels will be hugely beneficial to both of those groups. The only people who will really be hurt by such a transition are those who make profits from selling fossil fuels. Pitting 'wealthy' vs 'poor' populations just plays into the hands of those selling the lie that prosperity depends on fossil fuel use. That used to be the case, but for much of the world (and soon all of it) there are now better options.
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One Planet Only Forever at 14:23 PM on 9 December 2014Even climate change experts and activists might be in denial
I challenge any suggestion that 500 million people would be sustainable by highlighting how long humanity should be able to enjoy being a sustainable part of the robust diversity of life on this amazing planet.
The accumulating impacts of pollution are one thing, but a more relevant issue is that the consumption of any non-renewable resources, particularly burning them up, is unsustainable for almost any amount of human population.
The University of East Anglia recently released a report here forecasting that the Earth could be habitable for humans for 1.75 Billion more years.
With that knowledge, common sense is all that is required to recognise that the consumption of non-renewable resources needs to be curtailed from human activity in order for humanity to sustain itself through that amount of time. Some may argue that figuring out how to live that way is someone elses problem, or that they will be willing to live that way if someone else makes it cheaper and more enjoyable for them to do so (and refusing to accept higher costs for not living that way). Those are clearly poor excuses for not wanting to participate in supporting the rapid development of what is required for the future of humanity.
What is clearly required is the rapid curtailing of any benefit being obtained by already fortunate people from the burning of buried hydrocarbons. That would 'motivate' the development of sustainable ways of living. And there needs to be no different national rules for that requirement. Every very fortunate person should be required to behave far better, stop trying to benefit from the burning of the stuff, no matter what nation they are in. The only justified beneficiaries should be the poorest of the poor who would only benefit for the short time it takes the more fortunate to help them to transition to a sustainable decent life, with none of the 'helping more fortunate people' getting any benefit from the assistance being provided.
I believe that can help clarify why there is so much resistance to climate science and so many other developing better understandings of the unsustainable and damaging nature of popular and profitable activities. Many people do not like the thought of it. It requires an admission that they are not fully deserving of the 'good life they are enjoying'. And some of them prefer to believe that all would be great if there were fewer people. What they fail to realize is that the best benefit for the future of humanity would be for the 'reduced population to be exclusively the lowest consuming and impacting humans.
My preference would be for the highest consumption-impact people to willingly change their ways rather than being forced to behave better. However, it is clear that some people are very reluctant to participate responsibly toward the rapid development of a suatainable better future. And there is little point in asking them 'what they are willing to do'. They are clearly willing to try to get away with the most unacceptable behaviour they are able to.
Hopefully the number of real considerate leaders has increased since the last time global representatives tried to collectively effectively develop toward a sustainable better future for all. What is required is clearly understood by all the global representatives. Who stands in the way is also easy to see.
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wili at 09:39 AM on 9 December 2014California just had its worst drought in over 1200 years, as temperatures and risks rise
william (who is, may I point out, not the same as me!), your question is directly addressed in the article:
There’s been some confusion about the human influence on the drought because two studies published this year didn’t find a connection to the lack of rainfall. However, as Mann noted, those studies did not consider the three mechanisms listed above. They were incomplete.
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scaddenp at 09:35 AM on 9 December 2014California just had its worst drought in over 1200 years, as temperatures and risks rise
The actual statement in the article is "in fact, there are at least three different mechanisms that are potentially relevant to the connection"
I am not sure that "potentially relevant" is the same as "strongly implied". However, the 3rd mechanism is important. While there have undoubtedly been low rainfall periods in the past from other causes, higher temperatures worsen the intensity of drought ( which is what PDSI attempts to quantity).
It is extremely difficult to link any particular weather event to climate change - in general climate change only affects the probability of a weather event happening and its severity.
As far as I can see, the NOAA study only considers rainfall patterns, and the article above says, it does not consider changes to jetstream (very unsettled science admittedly).
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william11409 at 07:43 AM on 9 December 2014California just had its worst drought in over 1200 years, as temperatures and risks rise
This report is like so many in climate science in that two opposing explanations are put foward for the same event. Here it is strongly implied that the Californian drought is due to human activities whereas a report from NOAA scientists states it is not (www.usatoday.com/story/weather/2014/12/08/california-drought-cause-noaa/20095869/) Who to believe?
Moderator Response:[JH] What you are observing is the scientific process at work. Over time, the seeming contradictions will be sorted out. This sifting and winnowing process occurs in all scientific disciplines. Your suggestion that conflicting explanations are unique to climate science is bogus.
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dagold at 05:04 AM on 9 December 2014Even climate change experts and activists might be in denial
I am wondering about this: Do folks in the 'middle of the bell curve' who are aware of climate change, but in a 'peripheral' manner, look at headlines like "nations pledge to cut emissions 30%", etc. and believe that this means that GHG concentration in the atmosphere will actually decline? I am willing to bet that this is the case...that many people simply do not realize that, in a very best case scenario , the world reduces GHG emissions let's say 30% below today's levels by 2030 (taking into account that 'developing' nations will almost certainly not agree to ween off fossil fuels) that a significant amount of carbon will STILL be added on to the, by that time, 430 or so ppm CO2 level?....and that permafrost tipping points and carbon sink saturations could very well be 'exponentializing' the Keeling Curve by that point? In summary, my strong suspicion is that humans, for the most part, simply do not and will not 'grok' non-linear change and feedback loops until the on-the-ground destruction simply 'punches them in the face'.
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CO2 effect is saturated
WRT the effective radiating altitude, it's worth comparing the spectra of emitted IR to the atmospheric temperature profile.
Emitted IR, single point, US Standard Atmosphere:
Atmospheric temperature profile:
What's interesting is that for any GHG wavelength you can go from the amount of IR radiating to the temperature to the effective radiating altitude.
In the CO2 trough you can see emissions bottoming out around 220K, or -53C. At the tropopause temperatures are around -50 to as low as -70C, ~223 to 203K, indicating that valley and those wavelengths represent an effective CO2 emission altitude at the tropopause.
In the center of the CO2 trough where absorbance is particularly high there is a smaller peak - that comes from a small band of IR emitted by CO2 in the warming stratosphere. For most of the IR spectra the tropopause represents the upper limit on the effective radiating altitude. And for that very reason the upper end of convective overturning, as the energy necessary for the tropospheric inversion and convection radiates to space at that point.
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michael sweet at 02:59 AM on 9 December 20142014 SkS Weekly Digest #49
Real Climate has an excellent post debunking Watts "World Climate Widget" graph here (currently top post). Skeptical Science may want to post a similar OP, or just repost the Real Climate one. They link a widget that could be linked at SkS also.
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Alexandre at 02:39 AM on 9 December 2014Even climate change experts and activists might be in denial
JH (moderator),
I actually read that in one of his books, and I would have to be home to look for that... but a quick search on Google gave me this:
"He [Lovelock] also criticized growing demography, which causes pollution and over-exploitation of natural resources, stating that if the world population amounted to 500 million people none of the environmental problems that the world was then (and still is) facing would exist." (link)
Although I find that figure plausible, I don't think he provides details of the reasoning that led to it, even in his book.
Moderator Response:[JH] Thank you. As they say, "context is everything."
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Alexandre at 00:41 AM on 9 December 2014Even climate change experts and activists might be in denial
Wol at 23:45 PM on 8 December, 2014
If I remember right, James Lovelock put that figure in 500 million people.
Moderator Response:[JH] Please validate the figure you cite and provide context.
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Wol at 23:45 PM on 8 December 2014Even climate change experts and activists might be in denial
I keep, unapologetically, coming back to the fundamental problem: overpopulation.
The sustainable planetary population - with a modern standard of living - is probably less than 2-3 Bn.
Unless this is recognised an addressed we are bashing our heads against the brick wall - and climate change is only one aspect of the sustainability question.
Moderator Response:[JH] Please cite recent reports and/or peer-reviewed papers that underpin you position.
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Tom Curtis at 17:42 PM on 8 December 2014CO2 effect is saturated
Anne Hyzer @379, that is a very complicated graph that has been launched like an iceberg on an unsuspecting public. It is unsurprising that you have misinterpreted it (as I have on a previous occasion).
Teasing out the complexities, the first thing to note is that it is a graph of spectral cooling rates by pressure altitude and wave number. Because it shows cooling rates, positive values show a net cooling effect at that wave number. It is important to recognize that it is by wavenumber, as integrated across all wavenumbers (ie, into the ultraviolet), ozone has a net warming effect rather than the net cooling effect shown which appears to be shown here.
The second complexity is that the spectral cooling rate is the total emission less total absorption at that altitude and wave number divided by density times the heat capacity of the atmosphere at that level. The heat capacity is in fact not constant with altitude because atmospheric composition is not constant with altitude. In particular, the water vapour concentrations falls rapidly as you ascend in the troposphere. Further, density falls rapidly with altitude as well. Density scales very approximately with pressure in the atmosphere, so that at a pressure of 100 mb, the energy emitted minus energy absorbed is very approximately one tenth of what it would be for an equivalent spectral cooling rate at sea level. At 1 mb pressure, it is 1000th. That is a significant underestimate of the actual scaling due to the greatly reduced heat capacity at altitude as a result of the greatly reduced water vapour content.
Combining these two factors, and the title of the graph seen when you run your mouse over it here (which I assume you put in) and your interpretation of the graph are both completely wrong and misleading.
Adding further complexity is that the scale is not uniform (being linear below six, and logarithmic above it), and the colour scale was chosen to emphasize features in the stratosphere and hence are not terribly informative in the troposphere. Further, this graph is for Mid Latitude Summer conditions, and do not represent a global average.
As it happens, the original paper has a host of interesting figures which would obviate the confusion caused by the above graph without detailed discussion. Most helpful in this case is Table1:
As can be seen both upward and downward flux are highest at the surface, where the difference between them (net flux) is also smallest. At the surface, upward flux is 423.5 W/m^2 but downward flux is 346.9 W/m^2 leaving a net upward flux of 76.6 W/m^2. At the tropopause, upward is 287.6 W/m^2, downward is 22.3 W/m^2 and net is 265.3 W/m^2. At the TOA, there is no downward, so upward= net = 283.3 W/m^2. Further, because at any location, upward emissions from that location equals downward emissions from that location, we know that upward emissions from the stratosphere never exceed the downward emissions at the bottom of the stratosphere, ie, the 22.3 W/m^2 downward emissions at the Tropopause.
With that in mind, consider the chart of net upward IR flux below:
As you can clearly see, the net upward IR flux is smallest at the surface, and rises rapidly with altitude up to the tropopause. You will also see that doubling CO2 reduces the net upward IR flux. Table 1 from the original paper specifies the reduction in net upward IR flux due to doubling CO2 to be 2.8 W/m^2 at the TOA, and 5.6 W/m^2 at the tropopause. Given that the normal definition of radiative forcing is the change in net upward IR flux at the tropopause after equilibrium adjustment for the stratosphere, and that this is a Mid Latitude Summer atmosphere, these figures are consistent with the accepted forcing of 3.7 W/m^2.
Finally, one more figure from Clough and Iacono 1995:
This figure shows the change in spectral cooling rate for an increase in CO2 concentration from 335 to 350 ppmv (approx) among other changes. As you can clearly see, the effect is a warming effect in the troposphere (100 mb and lower) with most of the warming being in the wings of the CO2 band. There is a cooling effect in the stratosphere. (Note, this graph uses a more detailed resolution, allowing more detail of differences in wave number to emerge than in the more commonly shown graph.)
So, as figure 5 and plate 9 of Clough and Iacono 1995 clearly show, the CO2 effect is not saturated, and increasing CO2 warms the troposphere.
Note: In the original version of this comment, I made a blunder in interpreting Fig 5. The original text is preserved below in the interests of transparency. I have, however, struck it through to make it clear that (except where it agrees with the text above) it no longer represents my opinion.
Most helpful in this case is their plot of net upward IR flux by altitude integrated across the spectrum:
As you can clearly see, the net upward IR flux is greatest at the surface, and falls rapidly with altitude up to the tropopause. You will also see that doubling CO2 reduces the net upward IR flux. Table 1 from the original paper specifies the reduction in net upward IR flux due to doubling CO2 to be 2.8 W/m^2 at the TOA, and 5.6 W/m^2 at the tropopause. Given that the normal definition of radiative forcing is the change in net upward IR flux at the tropopause after equilibrium adjustment for the stratosphere, and that this is a Mid Latitude Summer atmosphere, these figures are consistent with the accepted forcing of 3.7 W/m^2.
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One Planet Only Forever at 05:07 AM on 8 December 2014Even climate change experts and activists might be in denial
Another way to think about the issue is to understand that those who are more aware and better understanding of what is going on actually understand that the current developed lifestyle of the highest per-capita consumers is illigitimate and unacceptable. They are aware that the pleasures of abundant carefree damaging consumption are unsustainable. Yet they want all the personal benefit they have gotten away with developing a taste for, and more.
Their desire to have the amount of enjoyment they get always be increasing leads them to demand that the solution to this issue, and so many others, must be the development of a way for them to continue to get all the enjoyment they are fond of getting away with, and more. Any alternative has to be cheaper and more enjoyable for them.
They fail to understand that the starting point for development which could constantly improve conditions for everyone on this amazing planet is for many among the most fotunate to actually accept a step down, a reduction of excess personal pleasure, comfort and convenience. The current developed enjoyment of most of the most fortunate that everyone else aspires to develop to is clearly undeserved, unsustainable and even currently impossible for everyone to develop to, let alone in the future when there is a dramatically diminished amount of easy to access non-renewable resources to fight over.
The impossibility and unacceptability of what many people want is clearly evident, yet they struggle to admit it, because they like what they have developed a taste for. They like to benefit at the expense of others, particularly at the expense future generatons or slave workers in foreign lands who cannot effectively challenge them regarding their inconsiderate attitudes and actions.
In other words many people like to get away with whatever they think they can get away with, and will even try to get away with not thinking about the unacceptability of what they are getting away with.
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PhilippeChantreau at 03:33 AM on 8 December 2014CO2 effect is saturated
Anne, I'm not sure that you're correctly interpreting the Iacono and Clough graph. It is essentially a heat loss diagram and shows the role of various GHG in stratospheric cooling. I'm sure Tom Curtis can help more.
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Jose_X at 02:59 AM on 8 December 2014Mercury Rising: 2014 Likely to Surpass 2010 as Warmest Year on Record
One Planet Only Forever, I'll try to be clearer by listing all of the key data that shows that the prior 12 months is currently the highest 12 month average.
12-Month, January, look for the highest value. It's .63C (134th)
12-Month, February, look for the highest value. It's .64C (134th)
12-Month, March, look for the highest value. It's .64C (134th)
12-Month, April, look for the highest value. It's .66C (134th)
12-Month, May, look for the highest value. It's .66C (134th)
12-Month, June, look for the highest value. It's .66C (134th)
12-Month, July, look for the highest value. It's .67C (134th)
12-Month, August, look for the highest value. It's .67C (134th)
12-Month, September, look for the highest value. It's .67C (134th)
12-Month, October, look for the highest value. It's .68C (134th) *** highest ever.
12-Month, November, look for the highest value. It's .66C (133th)
12-Month, December, look for the highest value. It's .65C (134th)Note, December starts the cycle that is why it is at 134 and not 133. When December 2014 rolls around, it will be the first 135 for the prior 12 month period (ie, that will be the first time there will have been 135 Jan, Feb, ... and Dec).
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Anne Hyzer at 01:32 AM on 8 December 2014CO2 effect is saturated
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Anne Hyzer at 01:28 AM on 8 December 2014CO2 effect is saturated
I understand that most radiation comes from the troposphere as you say, outside the CO2 band, but this source says almost all of the CO2 band's radiation comes from the upper stratosphere.
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wili at 14:10 PM on 7 December 20142014 SkS Weekly News Roundup #49B
Thanks again, TC. I do wonder what the main variations were in the assumptions of the various projections.
And thanks also for the explanation of the linear versus log thing--it was one of the other things gnawing at me about this study.
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Tom Curtis at 10:53 AM on 7 December 20142014 SkS Weekly News Roundup #49B
chriskoz @5, there has been a variety of research showing that, for whatever reasons, since the industrial revolution warming has been effectively linearly correlated with cumulative emissions. Based on that research, scientists have determined the trillion tonnes of carbon benchmark which approximately correlates with 2 C warming (which was determined by policy makers). By reporting their result in terms of milli-Kelvins per gigatonne of Carbon, Ricke and Caldiera have obviously attempted to connect their data to that line of research, so I simply rescaled to make the comparison.
Having said that, you are of course correct that CO2 forcing rises with the log of concentration so that a 1 gigatonne emission will have a much larger effect from a 289 ppmv base than it would from a 489 ppmv base. However, for their projections, Ricke and Caldiera used a 389 ppmv base, so that the linear approximation should be good over at least the range from 390 to 450 ppmv, ie, to the point were we exceed the 2 C limit.
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Tom Curtis at 10:44 AM on 7 December 20142014 SkS Weekly News Roundup #49B
wili @3, Ricke and Caldiera write:
"Across the 6000 combined projections, there is a high degree of concordance on the overall magnitude and general shape of global warming resulting from a CO2 emission (figure 1). A pulse emission of CO2 results in a stepwise increase in atmospheric CO2 content, followed by a slow decrease as the CO2 is taken up by the oceans and terrestrial biosphere. Global temperature rises in response to the CO2 forcing, but with a lag of about a decade due to the thermal inertia of the upper layers of the ocean. The maximum temperature is reached when the ever-decreasing rate of warming in response to the increase in radiative forcing is balanced by the slowly decreasing magnitude of radiative forcing of atmospheric CO2."
Figure 1 is, of course, the figure I have shown. Based on that, Max is the maximum temperature at a given year out of all 6000 projections, 99% would be the line such that just 60 projections are as warm as or warmer than that line in the given year, and so on.
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Trevor_S at 10:20 AM on 7 December 2014Even climate change experts and activists might be in denial
Professor Kevin Anderson stated in a speech in 2012 that we have not yet begun to counternace the changes we need to make. This still holds true.
Talk of putting in another airport etc rather than discussing shutting them down for example. Until the wider community starts to realise what's needed, all I can do is cut my CO2e emissions to as close to 2t per annum as I can, engage my peers and friends in debate about reduction and only vote for politiacns that have effective mitigation as part of their climate policy.
I don't agree with 5's approach of trying to educate his congressmen, just let them kow they can't count on your vote because of their support for climate denial. Same here in Australia, neither the ALP or the LNP have effective mitigation policies, so anyone concerned with climate change who thinks effective mitigation should be part of policy and votes for either is wasting their vote. Yet 90% or so of my fellow Australians vote for them, this shows me denial is at least 90%, regardless of what they may say in a poll.
Same with 7. I think that was the point of the article, denial is increasing necasue emissions are incerasing, saying you're concered about climate change and then flying to Bali for holkdays is the crux of what the article was about.
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chriskoz at 10:17 AM on 7 December 20142014 SkS Weekly News Roundup #49B
Tom@2,
How can you linearly extapolate mK/GtC into K/TtC in such straight manner while we know that the ECS in K/dCO2 in logaritmic? Did they "calculate" their tiny dT increments from radiative equilibrium + H2O feedback of did they simply intrapolate transient sersitivity from Charney?
Besides, the difference between 2.2 C per trillion tonnes of Carbon (result of your extravagant extrapolation) and assumed 2C/1000GtC for policy measures is so small compared to uncertainty that it's not worth mentioning.
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chriskoz at 10:04 AM on 7 December 20142014 SkS Weekly News Roundup #49B
"George Shultz gone solar" while being a good example that the mind of even most hardcore republicans is changeable, contradicts the claims by some people that mostly older "hard-core traditionalist" who cannot change their thinking process and their FF burning habits, deny the climate change. Shultz example shows that you can change your thinking and your habits at any age.
The bad news here is: the denialism will not die out naturally with the gradual passing of current GOP members. Younger generation that is taking over, like Ken Cuccinelli in VA who could be Shultz' grandson, is a prime example that denial will continue to thrive.
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wili at 09:01 AM on 7 December 20142014 SkS Weekly News Roundup #49B
Thanks, TC. One further question for now--what does "Max" mean in the graph you present from the paper? Is that 'maximum sensitivity'? 'maximum level of warming from all the model attempts'?? Or what? I'm afraid I still find it hard to determine the value, if any, of this study. How many feedbacks did they include, positive and negative? What were assumptions (if any) about aerosols' effects? ...
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Tom Curtis at 08:21 AM on 7 December 20142014 SkS Weekly News Roundup #49B
wili @1, it is a very interesting result. What it is not saying is that the time to reach the Equilibrium Climate Response (ie, approx 3 C per doubling of CO2) is just ten years. Rather, it is factoring in both the rise in temperature due to increased CO2 together with the fall in CO2 concentrations over time with further ocean uptake assuming no further emissions. As I have often noted, the two have approximately equal time scales so that the long term response to increased CO2 if we cease all further emissions approximates to the Transient Climate Response rather than the Equilibrium Climate Response.
In their model experiments they released just a single pulse of CO2 and hence had no additional emissions. The result is a warming profile over the following century like this:
There is an initial sharp rise in temperature during the period of most rapid response to the increase in CO2 (due to the response to the CO2 forcing plus the water vapour feedback), followed by a slow decline as the reduction in CO2 concentration slightly outweighs the continued feedbacks to the initial warming. It is not clear whether their models allowed for melting of permanent ice sheets, and hence for the full range of feedbacks, so that slow reduction may be a slow rise with all feedbacks included.
In policy terms, the paper contains some good news and some bad news. The good news is that if we cease all emissions, future temperature rises will rapidly come under control, and at a lower temperure than the ECS often quoted would suggest. With ongoing emissions as per the various RCP scenarios, however, temperatures will continue to rise well into the future. So the good news is only good if we take action to curtail emissions.
The bad news is that they find a 2.2 milli Kelvin temperature rise per gigatonne of CO2 emitted, or 2.2 C per trillion tonnes of Carbon. Current policy discussions assume that if total human greenhouse gas emissions can be restricted to just one trillion tonnes of CO2e, we have a 50-50 chance of avoiding a 2 C temperature rise. On these figures we need to restrict total emissions to 0.9 trillion tonnes to obtain the same percentage chance. It should be noted, however, that not all emissions are CO2, and other gasses are not as long lived in the atmosphere so that they will have a shorter time to peak warmth, and a more rapid decline in warming effect.
As a final point, in the paper Ricke and Caldiera suggest warming will last longer than 100 years. In fact from carbon cycle studies we know that it will last thousands of years, and potentially tens of thousands of years, albeit at a reduced level. However, the time scale for Earth System Responses to CO2 increase (ie large scale melting of ice sheets and changes in albedo to widespread changes in ecosystems) approximately matches the time scale for the reduction in CO2, so the decline in temperature over the long term will not be as rapid as the decline in CO2.
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shoyemore at 06:08 AM on 7 December 2014Even climate change experts and activists might be in denial
I take issue with the statement:
Climate denial is undoubtedly on the rise, particularly in those media-saturated markets of North America, Europe and Australia.
The data does not bear that out - for example in this George Mason U Poll: In Jan 2012, the number of people who "Believe Global Warming is Happening" was 57%, that peaked at 70% in 2012, but has been stable at about 63% since 2013.
Climate Change and the American Mind
What we have seen is climate denial becoming entrenched, and becoming part of the group identity of a whole political class, which may be a minority, but a powerful and influential one. It is not as simple as just following where the science leads any more.
My understanding is that the IPCC Report states that it is possible to maintain the 2C limit with economic growth, but with an impact obviously.
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wili at 03:26 AM on 7 December 20142014 SkS Weekly News Roundup #49B
WRT: "CO2 takes just 10 years to reach planet’s peak heat"
I wonder if some of the good folks here would have the time to do a main post on this. I frankly don't know what to make of it. Is this without including aerosols? Other feedbacks?? In their own graph, the line that says "Max" clearly peaks at about 30 years after initial emissions. In other words, I'm confused. And I'm betting many others are, too. So any further light you could throw on how to interpret this finding (Is it valid? Is there something they missed? If it's valid, is it 'good' or 'bad' news?...) would be greatly appreciated.
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One Planet Only Forever at 02:17 AM on 7 December 2014Even climate change experts and activists might be in denial
Alexandre @4,
Burning non-renewable buried hydrocarbons simply cannot be continued. Not only does the activity produce harmful consequences, not just excess CO2, it is simply a dead-end activity.
The future of humanity requires no person to succeed in benefiting from burning the stuff, except temporary benefit obtained exclusively by the least fortunate to develop to sustainable ways of living. The richest should be required to live totally sustainably.
The reality is that there already is not enough that is easily available for everyone to burn as much as they want. We already have had many vicious global battles as greedy pursuers fight over the ability to benefit more than others while they disguise and excuse their pursuits as 'fights for freedom' or whatever other deception might gather 'sufficient' popular support in the moment.
There are already many developed ways to live decently without burning any non-renewable buried hydrocarbons. The problem is the perception that "it is impossible to live decently without burning the stuff". And the largest promoters of that delusion are the people who have the greatest potential to personally profit from prolonging the burning of the stuff. That said, it is clear that anyone enjoying an unsustainable and damaging lifestyle would 'get less personal enjoyment' from living more sustainably. The resistance to giving up any excess pleasure and enjoyment is the real problem.
Future generations have no vote, marketing power, legal power, or investment and purchasing power today. That continues to keep people who are immersed in current day over-consumptive socioeconomic activity focused on things that are popular and profitable for themselves in their region in their time, to the detriment of others and the future.
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Alexandre at 23:59 PM on 6 December 2014Even climate change experts and activists might be in denial
I disagree with the article. You don't have to jump out of a ship to question the route it's taking.
Virtually everything you do today emits carbon. Leo DiCaprio could not make a film, and people could not watch it without emiting carbon. Skeptical Science could not be a website without carbon-based electricity to run the internet providers or people's computers. This does not mean denial. This means our society is based on a unsustainable system that requires polluting the atmosphere until -if unabated- it wrecks nature and agriculture.
I'm all for iniciatives to emit less, both individual and collective ones. I plant trees and gave up gasoline in my car (I use sugar cane ethanol). I recycle as much as I can, and help other households do so as well with my personal time and effort. I try to use as little electricity as possible. And I know this is not nearly enough to curb emissions.
If someone wants to campaign or lobby or research for a change in this system, he or she will have to travel, use electricty, eat food, wear clothes. This all has a carbon footprint today. I encourage this campaigner to be as effective and energy efficient as he can, but by all means, he should go on and do his work as well as he can, with my blessings.
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shoyemore at 21:19 PM on 6 December 2014Even climate change experts and activists might be in denial
Sou has a post on the survey here
Climate action priorities of the populace
AS she points out, it is an internet poll, therefore suspect, though the sample is huge.
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shoyemore at 21:06 PM on 6 December 2014Even climate change experts and activists might be in denial
Interesting survey - it is hardly lack of communication, since in the countries where these issues are most effectively communicated (Western Europe, North American, Australia, New Zealand) action on climate change rises into the Top 10. For example, in Western Europe it is the 6th most important issue, ranking just a hundred votes or so below "Freedom from Discrimination and Persecution".
You can also note that many issues ranking above action on climate change overlap with it heavily. You cannot address reliable energy, or access to clean water, or protection for rivers and forests, or affordable food, without bumping up against climate change in some form or other.
In other words, this is a complex output that demands more than a superficial reading.
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william11409 at 17:37 PM on 6 December 2014Even climate change experts and activists might be in denial
From a recent world wide poll of over 6 million conducted by the United Nations (vote.myworld2015.org), climate change is placed last in a list of 16 items of concern to people (data.myworld2015.org). Why is this so? Lack of effective communication? Lack of interest? Not affecting people's daily lives? No incentives to change habits? Don't believe the science?
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Tristan at 17:09 PM on 6 December 2014Mercury Rising: 2014 Likely to Surpass 2010 as Warmest Year on Record
I don't think it'll be a calendar record for UAH or RSS. Very hard for a non El-Nino year to set records in the lower tropospheric temperature series.
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Donny at 16:31 PM on 6 December 2014Volcanoes may be responsible for most of the global surface warming slowdown
So this would mean that some of the "missing heat" never actually made it to earth?
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elisat1 at 13:17 PM on 6 December 2014Mercury Rising: 2014 Likely to Surpass 2010 as Warmest Year on Record
jimlj @ 22,
Please define "calendar record". If you mean a record for global mean temperature anomaly in calendar year 2014, I don't see how you get that from the UAH data.
I did a quick average of the UAH monthly global anomalies over two complete calendar years. 2010 comes in at +0.40C, 1998 comes in closer to +0.42C while the 2014 averaged anomaly comes in at +0.272C through end of November. By that calculation, in order for the calendar year anomaly for 2014 to equal that for 2010, the December, 2014 anomaly would have to come in at +1.78C, in other words it would have to be the warmest month since December, 1978 (the start of the UAH table) by a factor of about 2.7.
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TallDave at 08:08 AM on 6 December 2014Phil Jones says no global warming since 1995
"When all the heat accumulating in the oceans, warming the land and atmosphere and melting ice is tallied up, we see that global warming is still happening."
Naturally this article fails to mention that since the hydrosphere is 271 times as massive as the atmosphere, if oceans are absorbing the heat they are likely to moderate AGW into a nonproblem, as the average ocean temperature has only changed by .1 degrees in 50 years, an amount that is probably smaller than measurement error.
Moderator Response:[PS] please note the comments policy, especially the section on sloganeering. There are numerous papers on measurement error and you wish to dispute that please provide evidence to support it. That the oceans ameliorate warming hardly needs stating - without oceans, we would have warming by 36C. If you wish to propose that somehow heat uptake can increase to make it a "non-problem", then provide evidence to back it. The evidence from papers in the IPCC reports do not appear to support your argument. Further speculative sloganeering without support will be deleted.
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wili at 03:42 AM on 6 December 2014Drought and Deforestation in Brazil
Thanks again for the info. Pretty much what I though. I imagine that most of the soybeans also go toward cattle feed. So pretty much our burger habit is obliterating the most populous area on this half of the planet...nice.
Meanwhile, as they scrape ever further toward the bottom of the barrel, water quality is getting noticably worse, and it's likely causing long-term damage to infrastructure: translate.google.com/translate?hl=en&sl=pt&u=http://noticias.portalvox.com/sao-paulo/2014/12/sabesp-registra-82-de-volume-de-agua-sistema-cantareira.html&prev=search -
SDK at 03:24 AM on 6 December 2014Models are unreliable
Just to add. How many in the general population would understand that today the model ensemble mean is correct because it strays away from the instrumental record? And that if the observed data was closer to the mean -— or even exactly on top it -— it would in fact be more wrong?
Now there’s a pedagogical challenge...
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One Planet Only Forever at 03:00 AM on 6 December 2014Drought and Deforestation in Brazil
Deforestation for ranching, plantations and farming is also a major reason for the reduction of Indonesia's rain forests.
And in many nations the ranching, plantations, and farming is not done for 'internal consumption'. In many cases it is done for international trade. In some cases less fortunate nations are fooled into accepting 'development' loans to build massive infrastructure that is promised to bring them 'properity'. And the infrastructure is specifically focused on international trade, it is not hospitals and schools. All that it brings them is insurmountable debt and a desperate desire to expand their production of basic commodities for international trade. And their expansion of that activity reduces global prices for commodities reducing the benefit they get, all while their debt payments grow.
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Phil at 02:26 AM on 6 December 2014The Beginners Guide to Representative Concentration Pathways - Part 3
There is one thing that seems to be missing from this (otherwise excellent) series. The relationship between CO2 emissions and their atmospheric concentration is known to be fractional (it is, if I recall correctly, currently about 45%) due to the uptake of CO2 by the oceans - acting as a carbon "sink" (and also resulting in ocean acidification). There is also some uncertainty over whether this figure will remain constant over time, but general agreement that it represents an upper bound on the ocean's capability to act as a CO2 sink.
So my question is; do the RCP's assume a constant ocean uptake of CO2 (at ~55%) or do they assume a decrease over time ? Also can we assume the uncertainty associated with GCM tempature projections do not include any contribution from the ocean uptake decreasing over time ?
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billthefrog at 02:23 AM on 6 December 2014Volcanoes may be responsible for most of the global surface warming slowdown
MarkR@11
"circumference divided by diameter"
I'm afraid that's just Pi in the sky, Mark.
;)
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SDK at 00:12 AM on 6 December 2014Models are unreliable
Thanks for the charts (from a fellow Tom who is also knee-deep into chart porn…)
Forget about the deniers, but these charts are not even close to addressing the concerns of the fencers either. At least when we need to attach complex disclaimers to them. I mean, if you ask say 90% + of the general population, they would have no idea what the ensemble mean actually erm… means in the first place. Isn’t that kind of a “double catastrophe” when you add the battle of public relations? We’ve won on the science, but losing badly in communications and framing the issue. Unfortunately, science doesn’t always fit nicely on a bumper sticker.
Sure, I can provide charts with the short-term weather noise removed, but then I’ll always be accused of chart manipulation… “after the fact”.
What if I had a chart e.g. from the early 2000s, showing that if the 3 main short-term natural fluctuations put a downward pressure on the GST in the coming years, it will produce a flattening of the curve? Further, why not just produce hundreds of those -— with a combination of premises -— which can subsequently be checked “after the fact”? As appendixes to the IPCC reports? Just asking as it sure as hell would've made my life easier arguing the AGW case on other forums.
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Tom Curtis at 21:52 PM on 5 December 2014Volcanoes may be responsible for most of the global surface warming slowdown
MarkR @11, perhaps circumference divided by wavelength? But other than that, yes you are correct.
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MarkR at 21:21 PM on 5 December 2014Volcanoes may be responsible for most of the global surface warming slowdown
I meant to say circumference divided by diameter...
Anyway, Tom's comments provide more detail as to why volcanic aerosols tend to have a cooling effect.
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Alexandre at 20:32 PM on 5 December 2014Drought and Deforestation in Brazil
wili at 13:43 PM on 5 December, 2014
The data I have about that are not very recent (one paper from 2009 and another from 2003, both in Portuguese), but I don't think this has changed much in the meantime. It's mainly cattle ranching (more than half), and agriculture to a lesser extent, especially soybean plantation.
It's interesting and sad to notice that logging is a very minor activity comparing to those. Often the deforestation process is done with tractors simply pulling the trees out and discarding the wood. Logging is not a first step to other activities, either.
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MarkR at 18:16 PM on 5 December 2014Volcanoes may be responsible for most of the global surface warming slowdown
Tom @8: there is a hidden wavelength dependence in Mie scattering. In the lecture notes you give, through the size parameter. This is labelled as 'x' in Eq. 9.36, and is (for a spherical particle) the diameter divided by the wavelength.
The scattering efficiency has a wavelength-squared depndence, even in the Mie regime. The phase function is also dependent on size parameter, with larger particles showing more forward scattering. And the scattering cross section also increases with particle size, assuming no major changes in the scattering efficiency.
So I'm pretty sure that aerosol scattering still has some wavelength dependence. It's weaker than Rayleigh scattering, but it is there.
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One Planet Only Forever at 16:00 PM on 5 December 2014Drought and Deforestation in Brazil
vonMackwitz @3,
Unfortunately this recent BBC article indicates that what you hope for is not as likely as it needs to be.
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