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Comments 17801 to 17850:
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RedBaron at 01:18 AM on 23 September 2017Climate's changed before
Scott0119,
You asked, "if we completely eliminate human CO2 emissions we could send ourselves into another ice age? Or am I oversimplifying the issue?"
According to this paper published in Nature: Evolution of global temperature over the past two million years , judging by the fossil record it appears as if we are locked into continued warming for a while at least even if we stopped all fossil fuel use tomorrow. Earth 'Locked Into' Temperatures Not Seen in 2 Million Years (all else equal of course).
However, all else need not be equal. Humans being a tool using species have the ability to do great works of ecosystem healing just as easily as we can do great works of destruction. In this case it means we have the knowledge tools and capability to sequester rapidly in the agricultural soils of the world more than enough carbon to "unlock" that "locked in" scenario.
Simply eliminating fossil fuels completely won't stop AGW. We waited too late for that. Sequestering carbon in our agricultural soils world wide by itself is probably too late for that too. But doing both ? That actually can finally reverse AGW, and such draconian measures need not be necessary. We could still burn a little fossil fuels and still have some ag that isn't carbon farming. In other words if we approach this from all angles we can drop it in as a replacement to all our unsustainable systems where economically feasable and the problem would vanish...and at a net economic profit!
I have written a rough outline essay how that might work here: Can we reverse global warming?
Here is a description of both the challenges and solutions we are facing in US: Can American soil be brought back to life?
Here is the same basic concept as developed in Australia: FARMING A
CLIMATE CHANGE SOLUTIONand
Why pasture cropping is such a Big Deal
And here is the Chinese efforts and early results for the same concept:
“Grain for Green” driven land use change and carbon sequestration on the Loess Plateau, China
Executive summary:
Yes we can reverse Global Warming.
It does not require huge tax increases or expensive untested risky technologies.
It will require a three pronged approach worldwide.
- Reduce fossil fuel use by replacing energy needs with as many feasible renewables as current technology allows.
- Change Agricultural methods to high yielding regenerative models of production made possible by recent biological & agricultural science advancements.
- Large scale ecosystem recovery projects similar to the Loess Plateau project, National Parks like Yellowstone etc. where appropriate and applicable.
Either way though, a glaciation event is not in any forseeable future. Quite the opposite problem.
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Scott0119 at 01:06 AM on 23 September 2017Ocean acidification
@geo guy @13. Concerning scrubbers. Would it be possible to to put scrubbers to use around the world to start cleaning the air in the atmosphere? Is that even feasible?
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Eclectic at 22:01 PM on 22 September 2017Climate's changed before
Scott0119 @574 etcetera : Quite so. There's no such thing as a stupid question per se, yet a poorly-worded question may give the impression that the questioner is being disingenuous or subpontine in intent. Especially so, in the context of making contemporary statements in other threads, giving a similar impression.
Cast your mind back to your School days, Scott, and you will recall that you were expected to do your basic homework. And picture what your Science teacher's opinion of you would have been, if you had skipped doing your homework, and you had then declared that you "were not yet convinced that the globe is round". Or if you had expressed similar baseless doubts about similar well-established facts.
Do your basic homework first, and then you will be able to ask intelligent questions. That makes for the most efficient use of your time. SkepticalScience is an excellent (indeed, award-winning) repository of scientific information. Read. Think. And you will find there are very few questions that you need to ask. Any clarifications needed — and excellent teachers such as Scaddenp are happy to help answer a genuine question arising from your "homework".
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Kevin C at 20:59 PM on 22 September 2017It takes just 4 years to detect human warming of the oceans
Barry @ 9:
It looks to me also like the uncertainty on the GMST trend is wrong. I can get a value in the same ballpark (but not the same as) theirs by leaving out the autocorrelation.
This makes no difference to the calculation in the opinion piece, since they do not use that value. However the trend uncertainty is itself derived from the value of sigma - I need to think about the implications of that.
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Scott0119 at 19:58 PM on 22 September 2017Climate's changed before
@ eclectic@572. "clearly" that is why I am here. I know these questions may seem uneducated but if memory serves from my School years if you don't know something ask.
@ scaddenp @573 thank you for your answer. You seem to have a grasp on teaching.
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scaddenp at 12:14 PM on 22 September 2017Climate's changed before
If we completely eliminate CO2 emissions, CO2 concentrations and temperature will continue to rise for some time, because once temperature starts to rise by any cause, all the natural feedbacks that amplify the ice-age cycle still cut in. Detail on our commitments here though carbon-cycle feedbacks are still major research topic. Because they are slow (hundreds of years), they dont affect our immediate future.
CO2 that we have already emitted stays there. There are very slow processes (millions of years) that gradually pull CO2 from the atmosphere. If we every needed to warm the planet, then very easy to make extremely powerful GHGs that would warm the planet again far more efficiently than CO2, but on those long time scales, you have to remember the changes in the sun too. Too many generations away for me to be much concerned.
Couldnt agree more about danger of humans interfering with mother nature. Our unplanned change in atmosphere concentration is biting us.
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It takes just 4 years to detect human warming of the oceans
Fool @ 7:
The "science" correspondents in almost all the media are hopeless. Even the better of them were putting the recent hurricanes down to AGW without caveats.
The only one I take any notice of is Peter Highfield, late of the BBC and other outlets, who puts out YouTube talks under the name Potholer54: masterly understatements and full of links to the relevant papers - unlike the deniers who just "know" their alternative facts are common sense right.
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Eclectic at 11:21 AM on 22 September 2017Climate's changed before
Scott0119 @571 , clearly you need to do a lot more reading to educate yourself on climate matters. Undertake some "science 101" basic education. Examples : read the climate science summaries on the websites of the U.S. National Academy of Sciences; of the U.K. Royal Society; of NASA; of NOAA; of the American Geophysical Union; of the Pontifical Academy of Sciences; or of other Societies of eminent scientists. If you prefer a more piecemeal approach, then select a few of the Climate Myths (see via the top/left corner of the SkepticalScience home page) — and read a number of them that interest you particularly [like with delving into a dictionary, you will soon find "nearby items" which will also interest you].
The "truth" which you quote may be less "immutable" than you think : but you are certainly correct that "human intervention on mother nature" [by injecting 100's of Gigatons of fossil-origin CO2 into our atmosphere] is definitely proving to be dangerous. It is high time that we all woke up to that !
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Eclectic at 10:28 AM on 22 September 2017It takes just 4 years to detect human warming of the oceans
Barry @8 and @9, "What you are missing" is the bigger picture.
The GMST warming trend you quote [of 0.016 degrees per year] may be plus or minus a particular "uncertainty" figure — but do you not think it would be crazy to therefore deduce that "There is nothing going on" / "Move along folks ... nothing to see here" ?
Take a common sense look at the bigger picture — since whether the expressed numerical uncertainties be tenths or thousandths of a degree, yet the polar ice is still melting away and the sea level is rising and glaciers are disappearing and plants & animals are changing their activities accordingly. The world is really changing — regardless of any "viewed-through-a-narrow-straw" type of blinkered assessment.
In overall terms, Pielke ( +/_ one generation ! ) is wrong-headed.
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Scott0119 at 09:43 AM on 22 September 2017Climate's changed before
Scaddenp, so what you are saying is if we completely eliminate human CO2 emissions we could send ourselves into another ice age? Or am I oversimplifying the issue? If there is one immutable truth it would be that human intervention on mother nature is usually dangerous.
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barry1487 at 09:39 AM on 22 September 2017It takes just 4 years to detect human warming of the oceans
John,
Is the GMST uncertainy for the period 2004-2015 in the opinion piece correct?
0.016°C ± 0.005°C per year
GISS has the same trend, but an uncertainty of 0.021.
What am I missing?
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barry1487 at 09:35 AM on 22 September 2017It takes just 4 years to detect human warming of the oceans
scaddenp @ 3,
Pielke Snr has been consistent on OHC being the best metric. He hasn't "stopped beating that drum."
Pielke Snr 2017: "Ocean heat content changes is, by far, the much better way to assess global warming. Ocean heat changes can be much more directly related to the radiative imbalance at the top of our atmosphere."
Nor did he limit that to the upper 750 meters.
"To be able to predict future climate change, in principle, it is necessary to be able to evaluate the actual current and future heating of the climate system from anthropogenic and natural sources as well as to evaluate where this heating is accumulating. For example, heat could be stored in the ocean at depths greater than 3 km (where observations were not reported in the Levitus et al. studies), instead of lost to space..."
http://journals.ametsoc.org/doi/pdf/10.1175/BAMS-84-3-331
You may be thinking of his comments on OHC papers which were about the upper 300/700/750 meters.
When he was blogging this view some years back, he tended to get criticism for it by those who (usually rightly) deconstructed 'skeptic' arguments. His papers don't rate a mention in the opinion piece linked above. I remember those to and fros, and it's disappointing that his earlier work has been sidelined in this recent opinion.
The time period assessed in the opinion piece seems way too short. 12 years? Better to do multiple series of that length than just one.
The GMST trend uncertainty for the period (2004-2015) is just wrong. They get a trend of 0.016°C ± 0.005°C per year. In all global surface data sets the uncertainty is larger than the trend for that period.
Possibly a typo, but as it appears twice, it doesn't give me much confidence in the piece in general.
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scaddenp at 09:26 AM on 22 September 2017Climate's changed before
Scott, the first important thing to understand is that climate is a reflection of the energy balance. If that changes for any reason, climate changes. Climate does not change by itself. CO2 was much much higher in the past, but the sun was fainter. We only got polar caps when CO2 dropped below a level for it to get cold enough. In the Pleistocene, CO2 dropped to point where the slow orbital cycles (Milankovich cycles) could drive an ice-age cycle due to variations in insolation happening at around 65N. Before that (the last time we had CO2 above 400ppm), you had icecaps but not ice ages.
Could they melt again? They will. The sun as a mainline star, is very slowly increasing its output and has been doing so since formation. At some point, a billion or so years into future, it will be too hot for liquid water. Eventually, as its fuel is exhausted, the sun will expand and probably consume all the inner planets - 5 billion years into future from memory.
A volcanic eruption on the scale of the Deccan traps could also push so much CO2 out that it warms the climate though that might be the least of our worries.
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Scott0119 at 09:20 AM on 22 September 2017Al Gore got it wrong
I really can't think of a worse spokesman for a scientific cause than a politician.
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Same Ordinary Fool at 09:00 AM on 22 September 2017It takes just 4 years to detect human warming of the oceans
1. I don't like, but can understand, some of the reluctance of video media (we'll exclude FoxNews) to mention "global warming" during hurricane coverage, because the complexity of the attribution would require too much explanation:
Not 'cause'...The ocean temperature...the frequency of all hurricanes, or just the 4's and 5's...rain and water vapor...wind shear...stalling, with speculation about jet streams... ...
2. They could alternatively emphasize the synonym of GW, 'higher temperatures'.
In partial compensation, the coverage could could increase the existing mention of Sea Surface Temperatures, beyond the existing color coding. As by mentioning the actual temperatures (does 30C correspond to category 5?). And maybe showing past smaller hurricanes' tracks with their cooler temperatures. Just saying 'hot' or 'hottest' doesn't fully describe the situation.
3. Heat content/temperature below the surface sometimes gets mentioned, but I've never seen it shown.
For today's hurricane Maria track, follow Google's "RSMAS Ocean Heat Content North Atlantic."
For some other examples, see the Google images at 'hurricane ocean heat content'.
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Scott0119 at 08:44 AM on 22 September 2017Climate's changed before
Please answer this hypothetical for me. If we stop all human CO2 emmisions tomorrow would the temp at some point warm the earth to the critical stages it has done in the past? Am I right to understand that the polar caps have for the most part melted in the past?
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Scott0119 at 08:29 AM on 22 September 2017CO2 lags temperature
As this is my first post on this site I will explain that I am not yet convinced of human caused global warming. I am on this site to gain knowledge so that I can make an informed decision.
i noticed a couple of you discussing the subject of how to label those of us who have not been convinced and those of you who are. To be blunt, labels tick people off! Why do we need them. Call them for what they are...convinced and not yet convinced or some benign variation. What the situation tells me is that this community has done a terrible job of explaining the issue. Katharine Hayhoe is an exception. She and I have tweeted back and forth on this subject and she has never made me feel stupid for asking questions. Not to mention some great videos she has posted. All should learn from her example.
Moderator Response:[PS] Welcome to skeptical science. We hope that you find the resources useful. While we discourage labels, there is a distinction between those weighing the evidence to understand scientific conclusions and those who ideological convictions cause them to deny scientific evidence altogether. If someone is skeptical about peer-reviewed science but swallow without question some garbage on a website that fits their convictions then they are well described as a pseudo-skeptics.
Please read and ensure you comply with the comments policy and you will find people here happy to answer questions. Dont make assertions without referencing evidence.
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NorrisM at 07:29 AM on 22 September 2017New paper shows that renewables can supply 100% of all energy (not just electricity)
Moderator and michael sweet
I have not had any reponse from michael sweet on my post on this thread on September 12, 2017 referencing the paper published by the Proceedings of the National Academy of Sciences in June 2017 which is severely critical of the Jacobson paper which was the subject of this blog originally created by an article on the Jacobson study posted by michael sweet in August 2015. I have only recently realized that michael sweet has indicated that he is not prepared to respond to any of my posts. I am not completely clear why.
I think in the interests of balance that SkS should acknowledge the criticisms that have been made by the NAS paper. I have now read that paper which is available publicly at http://www.pnas.org/content/114/26/6722.full.pdf
Although the 23 scientists, headed by Christopher Clack (of NOAA), are in complete support of effective ways to wean our society from fossil fuels by a combination of solutions (which would include a large solar and wind component), this paper effectively states that the Jacobson study is so full of modelling errors and implausible assumptions that it cannot credibly be used in any way to advance the questions that need to be answered to move this examination of alternatives (and their costs) forward.
I have recently praised the SkS website (agreeing with Joe Romm on a Sam Harris blog following Harris' interview of Romm on climate change) that the SkS website does a good job of providing valuable information. I may not agree with (or understand) some of it but I find it reasonably balanced.
In the spirit of providing balanced information, I would hope that SkS would make its readers aware of the serious criticisms that have been levelled by eminent scientists at the Jacobson 2015 study published by the Proceedings of the National Academy of Sciences (PNAS).
I do not think the Jacobson study should ever be referenced by any contributor to this blog without a caveat pointing the reader to the criticisms presented by this paper in June 2017.
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nigelj at 06:24 AM on 22 September 2017It takes just 4 years to detect human warming of the oceans
Swayseeker @5
The evaporative coolers use fans to induce a cooling effect, so I dont see how a mist comes into things or relates to evaporation as such.
I also don't see how you would apply such devices to the oceans in a practical way and you dont describe how. It looks very difficult.
You also need to provide calculations to show how many you would need at what cost. It would clearly be huge numbers probably staggering as you have thousands of square kms, even within the limited area that generates hurricanes like Irma, and you would need to cool pretty much all those oceans.
It could also have unintended negative consequences.
However wave powered pumps have been suggested to drive warmer surface water deeper down as below. These sorts of ideas arent new but have many difficulties in application.
www.vox.com/energy-and-environment/2017/9/8/16264376/stopping-a-hurricane-science
But this is not really the right website to float such ideas, this is a science website not a technology forum. It kind of really distracts me from the article above, and climate science. But Im not knocking novel ideas, but you must think them through.
Why not get involved with some website that deals with engineering ideas and get some feedback from the real experts on practicality and costs?
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One Planet Only Forever at 03:44 AM on 22 September 2017Australia's Transition to Renewable Energy
A serious problem is the popularity of the "continuity of affordable electricity supply" portion of the following part of the OP.
"... it is necessary to point out the fallacy of arguments put forward to justify future use of so called ‘clean coal’ fired ultra-supercritical power stations as the best means of ensuring emissions reduction and continuity of affordable electricity supply."
And the biggest part of the problem is people competing to Win Leadership deliberately making Poor Excuses for unjustified understandably unacceptable behaviour in the hopes that doing so will increase their popularity, increase their chances to win political leadership and Win the ability to get away with 'more profitable/less acceptable' ways of doing things.
Unjustifiably 'affordable/cheaper' energy supply should not be allowed to be excused just because 'it is what people have developed a taste/preference for'.
The 'undeniably less acceptable but cheaper' electricity supply over-developed in well developed places like Australia should have been ended a long time ago. The basis of that understanding was internationally established in the 1972 Stockholm Conference (more damage than the CO2 impacts, and ultimately unsustainable - not ways of living that the entire global population can develop to enjoy forever).
And the scientific basis for that understanding has steadily strengthened since that time. The current best understanding of the required chnages is presented in the 2015 Sustainable Development Goals (with the Paris Agreement being an important step toward achieving the climate action goal).
A Good Reason for continuing CO2 production from electricity generation wold be as a transition step for the 'sustainable' development/advancement of less fortunate people to better lives. However, nations with more than enough wealth to have their entire populations live decently, like Australia, have no legitimate justification to continue benefiting from burning fossil fuels. They certainly should not be able to excuse building new fossil fuel burning capacity. Those nations need to be reducing the benefit they get from creating any additional CO2 from burning fossil fuels rapidly to 'zero', even if doing so means that their electricity costs go up significantly (And the existence of less fortunate people due to inequity of distribution of wealth within such a nation would not justify that nation collectively being allowed more CO2 emissions. And that evaluation of inequity of wealth also needs to be applied to limit what is allowed in the developing nations).
The higher cost of electricity is what such 'supposedly more advanced nations' should have adapted to long ago. It would motivate the reduction of 'less necessary' electricity use and the development of lower cost 'acceptable' ways of generating electricity.
That understanding of the unacceptability of 'Ways of Winning' that the currently perceived to be more fortunate people have developed popular regional support for is very important. The related understanding that clearly has to become 'more common knowledge' is that 'it is undeniably easier to regionally temporarily drum up popular support for beliefs that excuse less acceptable attitudes and actions than it is to properly raise awareness and understanding'.
As an engineer, applier of science - constantly improving awareness and understanding of what is going on, my job is to first exclude unacceptable alternatives from consideration regardless of the desires of clients and those higer up in my work organization for things that were cheaper or quicker - never allowing cheaper or quicker to be considered to justify a less acceptable option, cheaper and quicker to achieve the required objective was all that was allowed. And if it was ever discovered that a previous way of doing things was actually producing an unacceptable result then nothing new would be done that way and previously done things would 'get corrected' no matter how unpopular or unprofitable that 'change' would be.
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Swayseeker at 23:55 PM on 21 September 2017It takes just 4 years to detect human warming of the oceans
Talking about the air temperatures fluctuating, my idea to cool oceans would cause havoc with readings, but would cool, I believe. If one has mist evaporative cooling ( see https://en.wikipedia.org/wiki/Evaporative_cooler ) with an efficiency of 80%, then sea surface temperatures of 27 deg C or so could drop below surface temperatures of 26 deg C or so needed for hurricanes. https://www.seatemperature.org/caribbean-sea says, "The water of the Caribbean is warm, clear and has lower salinity levels than the neighbouring Atlantic. The average water temperature is around 27°C (80°F) and varies as little as 3°C (37°F) throughout the year." Now 27 deg C is sufficient for hurricanes to form. The temperature also does not change much, so in future, sea temperatures could be high enough throughout the year for hurricanes to form. Example. Air temperature is 33 deg C (dry bulb temperature). The humidity is 70%. Calculation: The wet bulb temperature is 28.31 deg C and therefore an 85% efficiency evaporative cooling would cause the air temperature to drop to 29 deg C. Surface temperatures could be altered by these means
Moderator Response:[JH] Excessive repetiton deleted.
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jenna at 22:07 PM on 21 September 2017It takes just 4 years to detect human warming of the oceans
Is there a problem with the SKS website? I see only this one article when I go to the home page.
Moderator Response:[BW] The homepage display should be fixed now.
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Ken in Oz at 17:26 PM on 21 September 2017Australia's Transition to Renewable Energy
scaddenp - seems to me the building of new coal plants "anyway" is a serious mistake. Any appearance that they are cost effective are based on an enduring amnesty on the externalised costs.
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Riduna at 14:45 PM on 21 September 2017Australia's Transition to Renewable Energy
Given the high capital and recurrent costs of a USC power plant, how will it be able to generate electricity at a price which (a) does not put upwards pressure on the price of electricity and (b) how will it contribute to meeting our (modest/inadeqwuate) obligations under he Paris Accord by redcing our CO2 emissions? A USC power plant may result in (30%?) lower emissions but solar/wind generators result in 100% lower esmissions.
What investor in his right mind would invest in a hugely expensive USC power plant when far greater 'bang for the buck' can be obtained by investing in solar/wind supported by pumped hydro or battery storage?
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scaddenp at 12:01 PM on 21 September 2017It takes just 4 years to detect human warming of the oceans
Roger was only looking at 0-700m. You get heat loss from upper ocean to atmosphere in an El nino. He stopped beating that drum when OHC marched on upward. OHC is another important metric for quantifying climate change but I think it is too early for calling it the "standard" metric. Because the surface is where we live, surface temperature is what matters to us humans. My understanding is that it is not a trivial thing to extract OHC from models so dont know how climate modellers would feel about both their modelling skill in oceans and using OHC for validation.
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barry1487 at 08:51 AM on 21 September 2017It takes just 4 years to detect human warming of the oceans
“Ocean Heat Content” should become a standard metric not only for measuring climate change but for testing our computer models that are used to predict the future climate.
Roger Pielke Snr will feel vindicated by this conclusion. He's been saying the oceans are the best metric for many years.
https://pielkeclimatesci.wordpress.com/2006/08/30/mismatch-btween-models-and-observations/
By coincidence, in the 1st article, he notes that OHC had not risen by.... 4 years.
Is the corrollary here that we will not see another 4 years of no OHC rise as long as we're emitting CO2 at present rates? And should that happen, won't the contrarians point at this article to say global warming is over?
[BTW, wen clicking on the SkS home link, this article is the only one that appears. It's all blank below. I cleared the cache, but no result. Something's up with the site]
Moderator Response:[BW] Thanks for the heads-up, Barry. The homepage display should be fixed now.
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scaddenp at 08:00 AM on 21 September 2017Australia's Transition to Renewable Energy
Ken, well I realize it is PR, but the super-critical plants do have lower emissions per kWh of electricity produced than subcritical plants. If you are going to build a coal plant anyway, then I much prefer it is USC than convential cycle. Of course, it might be good to ask some hard questions about whether they are working as designed and what the actual heat rate from the plants are.
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Riduna at 07:33 AM on 21 September 2017Australia's Transition to Renewable Energy
Queensland, Victoria and South Australia do have plans for transition to renewable energy generation which involve provision if targets, provision of back-up (diesel generators, gas fired peaker stations) and energy storage (pumped hydro, batteries). Oz has over 20,000 sites suitable for pumped hydro with pumping powered by solar or off-peak existing coal-fired.
The Federal Government also has a plan, based on building additional coal-fired power stations and Snowy Scheme pumped Hydro. By the time these measures become operational, in 5-7 years time, battery and solar technology will have advanced to make coal fired power generation uncompetitive with renewables and overcoming present capacity limitations on electricity storage.
Recent calls by the National Party and right wing Liberals for all subsidies for renewables to be withdrawn, simply adds to investment uncertainty – a problem which State governments are overcoming by supporting the best renewable energy proposals. It’s a shame the Feds are so ideologically committed to coal. However, market forces will ensure a renewable future.
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ubrew12 at 04:18 AM on 21 September 2017It takes just 4 years to detect human warming of the oceans
Abraham: "ocean heat content is the key to quantifying how fast the climate is changing" Arguing online, I tell people that while global warming causes climate change, they aren't exactly the same thing. A useful proxy for 'climate change' is the surface temperature record. But when deniers note that that proxy hadn't changed temperature much for 12 years after 1998, they said 'global warming' had stopped. No, the proxy for 'global warming' is ocean heat content. I try to explain that, since the ocean is 200 times more massive than the atmosphere, trying to measure 'global' warming without it is like trying to discern the direction of a hurricane by measuring a pocket of air in its SW quadrant.
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Tom13 at 00:37 AM on 21 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
Moderator Response:
[PS] Discussion of Hansen 1988 goes here.Hansen's 1988 prediction is covered in four (4) paragraphs of this article - should be appropriate to respond in this thread
Moderator Response:[PS] Skeptic talking points about Hansen however are best discussed on the indicated thread where more context is available. I am concerned to ensure any wide ranging discussion of Hansen is in a more appropriate place as it is not the main point of this topic.
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Ken in Oz at 21:21 PM on 20 September 2017Australia's Transition to Renewable Energy
I find it very disturbing that super-critical coal plants have been renamed as "low emissions" - and much of the media in Australia have gone on to take up that deceptively misleading terminology without objection. Worse is that the definitions of "low emissions" under which support for emissions reductions are based are under threat of being rewritten by an openly pro-fossil fuels government to include such coal generation. Generation that in no respect is actually low emissions.
The Orwellian doublespeak in Australian public discourse is getting so commonplace that it actually appears to be successfully changing the fundamentals of the debate away from climate responsibility; energy policy is about cost and reliablity and on the rare occaisions gov't spokespeople mention emissions reductions at all it is in ways that imply those are entirely about kowtowing to international agreements, not about achieving climate stability.
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Digby Scorgie at 17:20 PM on 20 September 2017Australia's Transition to Renewable Energy
There's no bloody master plan in New Zealand either. Is there anybody with a master plan?
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Eclectic at 10:47 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
Thanks for that, OnePOF @16 .
It is worth re-emphasizing the bigger picture [as touched on, in post #4]
That is — until such time as a real pause can occur in nett radiational energy inflow at the planetary level [at Top Of Atmosphere], it remains impossible for any actual physical pause in global warming to occur. Essentially, a real pause or warming-trend slowdown can only occur after the atmospheric CO2 level has stopped rising. And there is no sign of that happening within the next 3 decades.
Sure, there will always be brief fluctuations in "trend", from minor natural variations in ocean currents and/or volcanic eruptions — but no pause is possible in real terms. To suggest otherwise is to commit obfuscation [to put it politely!] .
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nigelj at 10:37 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
Getting back to the article, picking just one of Hansen’s predictive scenarios was far too “selective” (choosing my words carefully) but I would go further and say its rather selective to focus just on Hansen. It would have been more representative to pick an average of all projections made at the time for "business as usual"
I say this with huge respect for Hansen who is quite possibly some kind of genius, but the world doesn’t revolve entirely around him and Al Gore. A lot of people have concluded we are warming climate going right back to Arrhenius a century ago.
Moderator Response:[PS] You said it. Hansen had his sensitivity too high in 1988 for reasons that are actually interesting. You dont see pseudo-skeptics giving much attention to the oldest quantitative estimate for global warming - Broecker's paper of 35 year ago.
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One Planet Only Forever at 10:01 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
Tom13,
I have used the SkS Temperature Trend Calculator with the 15 year rolling average (180 months) the Met Office used. The 15 year average would show some of the variability of global averages that does not appear in longer roling averages.
I do indeed see a levelling off of the trend line in the teperature data sets when looking at that 'shorter-term trend line'. The leveling-off occurs in the early 2000's not at 1998. And the level period is quite short with a clear return to the rate of rise that was occurring before the brief leveling off.
It is harder to see the change of short term trend in the satellite data sets. But the satellite data are not surface temperature so the less noticeable change of trend in those data sets are not really a relevant issue.
Note that using a shorter term rolling average would show an even 'noisier' trend line. Using a 60 month average makes it very difficult to see the actual trend in any of the data sets (lots of ups and downs). And using a 13 month rolling average is almost useless for appreciating what is actually going on in terms of the long-term.
Moderator Response:[PS] This is straying offtopic. If want to talk more about models reliability, then the "Models are unreliable" thread is more appropriate. And Tom13, note models have no skill at decadal level prediction and dont have claim to have any so no sloganeering around that please.
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John Hartz at 07:59 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
Tom 13 @10:
If you read the Met Ofice news release, A Pacific flip triggers the end of the recent slowdown, and watch the two short videos embeded in it, you will learn that PDO and ENSO are two different cycles.
Two key paragraphs from the news release...
Prof Stephen Belcher said: “After a period during the early 2000’s when the rise in global mean temperature slowed, the values in 2015 and 2016 broke records and passed 1 °C above pre-industrial levels. Data from the Met Office shows that the long-term rate of global warming has now returned to the level seen in the second half of the 20th century.”
Although there has been scientific debate about the exact framing of the so-called ‘slowdown’, by looking at rolling 15-year trends, the Met Office confirmed that while the globe remained at near record warmth, the rate of global warming did slow between 1999 and 2014, but now this rate has picked up once more.
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nigelj at 07:23 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
Even 2015 - 2016 would not normally prove anything or indicate fundamental change. It's too short and mixed in with some natural variation, and some agw.
2015 - 2016 is significant mainly because it clearly ended the pause, and this is indeed significant as it shows models are not "broken" and never were.
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One Planet Only Forever at 07:15 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
Tom13,
I am not sure what you are talking aboutregarding trends around 1998.
When I review any of the temperature data sets using a rolling 30 year average (what you would look at to see a 'trend') I do not see any marked change of the slope/trend at 1998. (The exercise I refer to is simple using the SkS Temperature Trend Calculator, just set the moving average to 360)
In the surface temperature data sets there is a flattening in the 50s and 60s. But since then the trend line has just been up. Other than that clear trend change, all I see is a momentary blip in the data line that may disappear if 1998 is igonored as an aberrant value (such a large departure from the other data it is to be excluded from the evaluation).
The satellite data sets are not really the surface temperature, are manipulations of satellite data that are still being adjusted in attempts to get reasonable results, and have too short of a time frame to meaningfully see the trend. But if you set the duration to 25 years (300 months) there is still no sign of a change of trend around the time of 1998 in any of the satellite data sets.
So to be clearer, please explain what you mean when you refer to trends around 1998. Providing mark-ups of the charts of temperature data history that can be generated using the SkS Temperature Trend Calculator would be helpful from my perspective.
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nigelj at 07:12 AM on 20 September 2017Australia's Transition to Renewable Energy
There seems a lack of a master plan here. They appear to be making it up as they go along. I appreciate its partly politics, but its chaotic and a bit scary.
Say for example if Australia has total reliance on a mix of solar and wind (which seems the sensible thing given their climate) then you will need "x" quantity of gas fired backup, or alternaively "y" quantity of surplus solar and wind as a backup, or alternatively "z" quantity of storage. Or some combination of these. Surely someone has some sort of master plan and calculations? I would be interested if anyone knows and can point me at specific information.
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nigelj at 06:50 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
Tom 13 @5
"The rate of warming since the end of the 2015/2016 El Nino has been very similar to the rate of warming post 1998 El Nino."
Why would you even focus on changes of less than even one year? Its at least partly natural variability, so doesn't indicate anything much about agw. It may continue at a slower rate for a few years as you say, for what its worth but so what?
We are more interested in long term trends. We have an obvious global warming trend over particularly the last 50 years that stands out clearly compared to data over the last 2000 years as in link below. No real sign of last 50 years slowing.
Theres no sign of things fundamentally slowing from 1998 - 2017 either. There was a slowdown from about 2002 - 2010 in the trend line as in the link below from NASA, but it was within realms of natural variability.
I mention all this because you claim to be interested in "historical trends".
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Tom13 at 06:28 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
Nigelj #9
read my post at 10
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Tom13 at 06:01 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
One planet - not sure what you asking -
1998 was a big el nino year and subsequent to the 1998 el nino, the rate of warming slowed considerably until the 2015/2016 el nino. My comment was only that the rate of warming after the 2015/2016 el nino has reverted back to a similar rate of warming that was observed after the end of the 1998 el nino. That slower rate of warming is likely to continue at least in the short term (3-5 years).
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nigelj at 05:55 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
Tom13 @5
"My basis - Historical trends - always a good place to start."
Then follow your own advice. Look at the overall global temperature trend for the last 150 years, a clear historical trend. Theres no sign of a slowdown here.
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One Planet Only Forever at 05:43 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
Tom13,
Just to be clear, are you referring to the temperature trend that can be seen to have been happening around 1998 if the extremely aberrant 1998 temperatures are ignored? Looking at any of the surface temperature data histories 1998 sticks up/out like a sore thumb.
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Tom13 at 05:27 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
A Pacific flip triggers the end of the recent slowdown, News Release, Met Office, Sep 18, 2017
Thats what normally happens after an el nino. though eclectic was the one who questioned the reversion back to a similar warming trend that was in play after the 1998 el nino.
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John Hartz at 05:25 AM on 20 September 2017It's Pacific Decadal Oscillation
Recommended supplemental reading...
Following three record years for global surface mean temperature in 2014-2016, the observed recent slowdown in average global temperature has ended.
A Pacific flip triggers the end of the recent slowdown, News Release, Met Office, Sep 18, 2017
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John Hartz at 05:07 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
Tom 13 @5: Per the Met Ofice...
Following three record years for global surface mean temperature in 2014-2016, the observed recent slowdown in average global temperature has ended.
A Pacific flip triggers the end of the recent slowdown, News Release, Met Office, Sep 18, 2017
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Tom13 at 01:21 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
Eclectic -
Tom13 @3 : quite so — though you are bold to predict a flattening of the rate of warming (for 2017 onwards). Do you have any reason for suggesting that?
My basis - Historical trends - always a good place to start. The rate of warming since the end of the 2015/2016 El Nino has been very similar to the rate of warming post 1998 El Nino.
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Eclectic at 01:06 AM on 20 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
Tom13 @3 : quite so — though you are bold to predict a flattening of the rate of warming (for 2017 onwards). Do you have any reason for suggesting that? After all, there has been no reduction of the rate of heat energy accumulation (i.e. no reduction of the rate of nett energy inflow at Top Of Atmosphere).
The "geoethic" reference you supplied, is a link to a determinedly foolish denial of the physical processes that are causing the ongoing global warming (as evidenced by recent years' observations of surface temperature and ocean heat content). It's a case of denialism both stubborn and foolish.
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Tom13 at 23:06 PM on 19 September 2017Scientific models saved lives from Harvey and Irma. They can from climate change too
I agree that it is inappropriate to only compare Hansen's A scenario against actual observed temps.
Hansen had three basic scenarios A: increase in CO 2 emissions by 1.5% per year, B: constant increase in CO 2 emissions after 2000, C: No increase in CO 2 emissions after 2000.
Through 2013, the observed global temps were slightly under the C scenario while the emissions were running slightly ahead of the projected A scenario. Then in 2015& 2016, with El Nino, the observed temps are running slightly under the Scenario B projected temps. So far in 2017 (after the 2015/2016 El Nino), the temps appear to be reverting back to the rate of warming observed since the 1998 El nino. (it is premature to reach a conclusion as to whether the slower rate of warming will hold since we only have 8 month of data.)
geoethic.com/2015/11/27/james-hansens-climate-models-versus-observations-1958-%C2%AD2015/
Moderator Response:[PS] Discussion of Hansen 1988 goes here.
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