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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Recent Comments

Comments 22851 to 22900:

Dcrickett at 02:26 AM on 10 October 2016

2016 SkS Weekly Climate Change & Global Warming Digest #40

Re #1: Some Moslem women wear the various forms of dress because it makes them feel more comfortable. Period.

My daugher married into an immigrant semi-Moslem family. Her mother-in-law (Phi Beta Kappa, Bryn Mawr) wears a hijab to prayer, otherwise dresses like most American women (albeit more tastefully). One of her daughters is more conservative. My daughter and son-in-law are fully secular. A fine family.

My wife, who is Hispanic by upbringing and modest by nature, had trouble appearing in public in a traditional one-piece swimsuit. Her friends at church told her they'd die to have a figure like hers to show off in a swimsuit.

My daugher went to college in France for a couple of years. She and some Americans went to a beach topless. Today she laughs about it; she had a very difficult time being blasé about it at first, but then she got used to it; to the French girls in her group, the American girls were funny.

Leslie Graham: Cool it.

Eclectic at 22:42 PM on 9 October 2016

Temp record is unreliable

Pink @379-382 , you will have to explain your ideas more clearly.

You seem to be stating that the world surface temperature has been swinging back and forth like a pendulum, between hotter and colder every few centuries.

But that's not really so. If you have a look at scientific temperature assessments of past times, you will see that the average worldwide temperature has been slowly falling during the last 6,000 years. There have been localised (regional) variations, particularly in parts of the Northern Hemisphere - but these have been very minor variations indeed (though often given very grand names, like "Roman This" or "Medieval That" or "Little Ice Age" etcetera, which make them sound far bigger and more important than they actually were). But overall there's been a slow cooling until now.

The major worldwide swings in heating/cooling have occurred on a scale of thousands and tens of thousands of years (including the "Ice Ages" = more correctly called the "Glacial Ages"). Those big swings have occurred for a reason - predominantly from subtle changes in Earth's tilt and orbit.

But nowadays we are in a completely new ball game : temperature rise very fast in the past 100+ years and being caused by a new factor - the new factor being a large rise in greenhouse gas effect from "fossil fuel" CO2. This really is very new and different, compared with recent millions of years.

Very strangely, Mr Heller/Goddard seems to be trying to misinform you and give you the impression that the world has been cooling since the 1930's. He couldn't be more wrong - and you can see the evidence that he's wrong, by looking yourself at all the melting ice and rising ocean level and all the other stuff that's going on to show that rapid global warming is occurring. Exactly as all the climate scientists are saying.

You would have to ask yourself why Mr Heller/Goddard is going against common sense!!

MA Rodger at 22:12 PM on 9 October 2016

Temp record is unreliable

pink @382.

I don't know of evidence for a natural warm era of any significance for which "the 1930's was probably the peak of several hundred years of warming."

The IPCC graphic (AR5 Fig BoxTS5.1) below shows a NH temperature reconstruction. While this reconstruction does show a period of NH warming over the last 300-400 years, the top panel of the graphic shows the majot agent of forcing to be the "well mixed GHGs." So it is mostly not natural warming.

And do be mindful of the implications of your proposal. You suggestion is that man-made climate change is responsible not just for the +0.99ºC temperature rise 1934-2015, but also some additional warming to reverse the onset of your proposed "cold period." How much additional warming would depend on the strength of your proposed "cold period," the significance of which I couldn't begin to assess as your proposal in my view an entirely fanciful.

IPCC FIGBOXTS-5.1

pink at 21:08 PM on 9 October 2016

Temp record is unreliable

I didn't say it was a 'warm era', what I meant was that it was just the peak of THIS warm period. The Roman warm period, followed by the 'dark' cold period, followed by the medeival warm period, followed by the 'LIA' cold period, followed by the current warm period. The 1930's was probably the peak of several hundred years of warming.

Moderator Response:

[PS] This is more sloganeering. Please back your assertion "the 1930's was probably the peak of several hundred years of warming" with some shred of evidence. As other commentators have shown, there is massive evidence against this.

MA Rodger at 19:59 PM on 9 October 2016

Temp record is unreliable

pink @380.

The warm 1930s experienced by parts of the US does not constitute part of "another post Roman warm era, post medeival warm era." It was solely a regional warming. If you use this GISTEMP mapping tool, you will see that for the year 1934 it is only a tiny part of the globe, indeed only a tiny part of the USA that plots a temperature anomaly +2ºC (and the global average is -0.14ºC). But for last year 2015, the map shows the +2ºC area is much much greater (and the global average is +0.85ºC).

In the grand scheme of things, climate is a global thing. As such, it would be an utter fool who insisted that the global view should not be "your outlook."

pink at 18:40 PM on 9 October 2016

Temp record is unreliable

1 other thing, his graphs are not showing that "we're going into an Ice Age" They just suggests that the 30's were the peak of the current warm period, which will naturally end as the Earth goes into another post Roman warm era, post medeival warm era, cold era. I take it you guys think that warm periods are now permanent and humans have to 'cap' the warm era so it doesn't get too warm, and they can do this by not burning stuff. Is that your outlook?

pink at 18:20 PM on 9 October 2016

Temp record is unreliable

OK thank you for the extensive reply. Basically what your saying is that he uses the unadjusted temps and the noaa has adjusted historical temperatures for "systemic errors" and other things. But I would be suspicious that these 'hot daily lows' you mentioned are the result of black asphalt, concrete etc. at night time. I have personally felt this effect, riding a motorcycle in a built-up tourest area(small town) in a hot climate I went back to my bungalow at about sometime after 2am. driving down a narrow road surrounded by vegitation, I'm wearing only T-shirt & suddenly it gets very cold, like i have to slow down because suddenly i'm freezing. I'm skeptical that these adjustments can ever be accurate when we're only talking about a degree or so since the 1800's.

The only solution seems to be to use only very consistent climate network instrumentation in area's that are far from any human activity for a long time.

What you said about this only being the USA. What skeptics are saying about that is most countries have not been in the business of measuring climate other than the USA. Czarist Russia did not see measureing 'climate change' as a priority, neither was the German Kaiser. Lawerence of Arabia and King Faisal did not battle the Ottoman empire and take temperature readings.

Moderator Response:

[PS] This is dangerously close to sloganeering. If you want to quote "pseudo-skeptics", make it a direct quote and cite. These sentences are unsubstantiated nationalist rhetoric and the last sentence absurb. I doubt Davy Crockett didnt battle with the Mexicans and took temperature readings either. The global tide gauge record and glacial retreat are consilient with the global instrument record and would strongly contradict a cooling since 1930s. Cherry picking of evidence in denier tactic. I am quite sure that the glories of Chinese science would be lauded if there was a Chinese record that suggested some cooling.

Tom Curtis at 17:00 PM on 9 October 2016

Temp record is unreliable

pink @375:

1) First and most obviously, the data is for the contiguous USA alone, and is not indicative of global temperatures.

2) The 1930s were noted for some years with very large areas showing some of the hotest temperatures on record, along with months in the same years showing large extents of very cold temperatures. That shows up in a spike in maximum temperature records, and in a spike in minimum temperature records; but the end of the 20th century, both minimum and maximum temperatures have increased. That results in a stronger increase in the mean temperature than occured in the 1930s. Heller carefully selects data that obscures that fact.

In the post by Heller I found which discusses these charts, he actually compares directly the NOAA graph of hot daily highs, which he purports to reproduce. That graph, however, also shows hot daily lows, which obviously climb much more at the end of the century than in the 1930s; again resulting in a greater increase in mean temperatures at the end of the century.

3) Heller graphs a simple count of the number of USHCN stations, but compares it to a graph of the percentage of the CONUS surface area affected by hot temperatures. Given that USHCN stations are very unevenly scattered across the CONUS surface, the two would not have the same shape unless exactly the same regions experienced heat waves in the 1930s as at the end of the century. The map of areas of the US that have experienced more (red) or less (blue) high temperatures since 1948 shows clearly a decrease across the midwest and most eastern regions (which have a very high number of stations) whereas the increase has mostly been in the west (with a very few number of stations):

The 1930s heatwaves, in contrast, were centered on the midwest (with a high number of stations):

Not using percentage of land area rather than numbers of stations in making the comparison shows either an absolutely abysmal level of incompetence, or a very deliberate fraud.

4) Heller uses an asolute temperature criterion, whereas NOAA uses a criterion depending on the percentage of the time a station exceeds a particular temperature. That is because what counts as a heatwave in Maine might by considered a cool spell in Miami. Thus the annual mean temperature in 1936 for Florida is "Near Normal", despite being 12^oF warmer than the "record warmest" temperature for Montana. Again, this change in method will distort the comparison unless the geographical pattern of temperature variation is identical in different years (as it clearly is not).

5) Heller probably uses unadjusted temperatures, despite there having being a clear downward bias in the raw data due to changes in instruments used, in times of observation, station moves, etc.

FrankShann at 16:36 PM on 9 October 2016

Temp record is unreliable

James Hansen has recently suggested using an early-industrial baseline of 1880-1920 (rather than 1951-1980) to plot GISS temperature anomolies in "a better graph" (www.columbia.edu/~mhs119/Temperature/ and http://csas.ei.columbia.edu/2016/09/26/a-better-graph/).

To find how to convert from 1951-1980 baseline to 1880-1920, I calculated the mean anomoly for all 41 years of GISS for 1880-1920 to be -0.276 ^oC (and, reassuringly, 0 ^oC for 1951-1980) using the annual temperatures at http://data.giss.nasa.gov/gistemp/graphs_v3/Fig.A2.txt

Therefore, to calculate the change in temperature relative to 1880-1920 for GISS, do you add 0.28 ^oC to the temperatures at nasa.gov? For 2015, that gives 0.86 (from nasa.gov) + 0.28 = 1.14 ^oC which approximates the value for 2015 in the graph at columbia.edu.

Tom Curtis at 16:14 PM on 9 October 2016

CO2 has a short residence time

Richard @151, to a first approximation, what happens is that CO2 concentrations fall as the ocean absorbs excess CO2 up to an equilibrium point. At the same time, the temperature response to the CO2 approaches equilibrium itself, a process that given constant CO2 concentration would see the temperaure response increase by about a third. The two processes have similar time scales, so that the temperature response in fact remains almost constant. This has now been shown by several teams, with slight divergences in the overall result. For instance, you may want to look at Frolicher and Joos (2010).

Of even more interest, however, is Friedlingstein et al (2011). That is because not only do they show the consequences of (the obviously impossible) complete cessation of emissions (a &b); but also the consequences of three plausible emissions reduction rates of 5, 3, and 1% per annum commenced immediately (c&d); and also of the 3% per annum reductions commenced 10, 20, and 30 years into the future (e&f):

They also show other permutations such as a 90% reduction (which shows an ongoing long term temperature rise) or 105% reduction (ie, net negative emissions, which show a long term decline in temperature, but not brining it below preindustrial levels for nearly a thousand years).

Eclectic at 15:57 PM on 9 October 2016

Temp record is unreliable

Pink @ 375 , the guy called Tony Heller also calls himself Steve Goddard.

He is well-known for his "economy with the truth" - indeed, he is notorious for his misleading presentations. Pink, you should always look very skeptically and carefully at anything he presents (under either name).

Here, if we generously assume he has not presented false or distorted information, then we should next look to see :-

(a) if he used data which is out of date (outdated because the temperatures were not corrected for systematic errors in themselves, or in relation to worldwide standardising methods).

(b) if he has cherry-picked data which he thinks is good "denier" propaganda - while carefully avoiding presenting the vast amount of data which points in the opposite direction.

(c) if he has used only continental USA data and not worldwide data. The worldwide records show strong warming, and continental USA records being only 2% of global area, are therefore rather unimportant in comparison.

(d) if he has not been contradicting himself by also (elsewhere) claiming the denier meme that CONUS temperatures are showing higher over the past half-century but only because of the Urban Heat Island Effect. ( Pink, as a well-informed guy, you will of course be aware that "UHI Effect" has been completely debunked as a cause of apparent rising temperature records ). You have to laugh when you see deniers trying to play for both sides at the same time !

Another interesting point is that there certainly were some unusually hot summer days in central continental USA in the 1930's. It is uncertain if they were the entire cause of the Oklahoma-type droughts - or whether they were (in part) a consequence of desertifying effect from extensive poor management of those agricultural areas.

A further point, Pink, is to find comparable graphs of night-time low temperatures for summer , and also find graphs of day/night winter temperatures. You might find those to be very interesting, in comparison ! Has Mr Heller/Goddard supplied those, too ?

A final matter, Pink, is the important common sense test you yourself can apply to Mr Heller/Goddard's graphs - graphs which on first glance seem to indicate a rapid trend toward a New Ice Age. Look around you : warming changes are already happening within CONUS, and even more strongly in Alaska - and most of the "non-CONUS" world is recording higher temperatures and new records in heat waves. Sea levels are rising faster and faster; huge amounts of glacier and arctic ice are disappearing. The ocean is warming ( and acidifying from excess CO2 ).

Mr Heller/Goddard is clearly very wrong in what he is implying.

Richard13791 at 14:33 PM on 9 October 2016

CO2 has a short residence time

Given that CO2 remains in the atmosphere for a very long time, the present amount continues to cause warming. To set a lower boundary on the problem, let’s say that ALL new human-produced CO2 and methane added to the atmosphere is reduced to ZERO starting tomorrow. Using current models, what is then the predicted change in average global temperature in 2100? Has anyone run such a simulation?

pink at 11:30 AM on 9 October 2016

Temp record is unreliable

Tony Heller has created a bunch of charts like these above, they all show it was hottests in the 1930's, how do you explain that?

pink at 11:28 AM on 9 October 2016

Temp record is unreliable

% of days over 100*

pink at 11:26 AM on 9 October 2016

Temp record is unreliable

Stranger8170 at 10:06 AM on 9 October 2016

Pew survey: Republicans are rejecting reality on climate change

In 2009, Pew Research Center surveyed scientists in all fields of science. Only 6% of them claimed the Republican brand. My guess is that number might even be lower today.

It seems fitting because today Republicans have little trust in science. It only stands to reason that if the base doesn't trust science that at some point it begins to effect researchers. It's sad because a few decades back the number researchers who claimed the Repubican brand was near 50%.

http://www.people-press.org/2009/07/09/section-4-scientists-politics-and-religion/

jja at 06:11 AM on 9 October 2016

2016 SkS Weekly Climate Change & Global Warming News Roundup #41

Hey! Did you guys discontinue the "Tracking the 2C Limit" page??? please continue the valuable series, we need it now more than ever!!!

RedBaron at 04:35 AM on 9 October 2016

Models are unreliable

John,

I have no doubt you are right John. I have every respect for the mathematicians doing the models. They are remarkably close considering the difficulty of the task, and getting better as time goes on. I was simply addressing the claim that there was somehow some conspiracy or something where hindcasts was somehow wrong. It isn't as long as the reason for it is to check the skillfulness of models as you improve them. Hindcasts are a valuable tool, used properly.

John Hartz at 02:54 AM on 9 October 2016

Models are unreliable

@RedBaron #992

In many cases, the "old data" is also being refined.

In addition, the scientific and technical teams engaged in the care and feeding of Global Climate Models are highly skilled and dedicated professionals. In other words, they know their stuff better than do any of us.

MA Rodger at 02:26 AM on 9 October 2016

Models are unreliable

Concerning Nate Silver's 'The Signal and the Noise' book cited @989, I note Michael Mann has a number of serious criticisms of its coverage of climate modelling (although Mann does admit that his use of five-hundred-and-thirty-eight quoted as being 'The Number of Things Nate Silver Gets Wrong About Climate Change' in his title is “poetic license”).

Bob Loblaw at 00:32 AM on 9 October 2016

Models are unreliable

Another example of "predicting the past" would be a geologist searching for gold. She might come up with a new hypothesis ("model") of how gold deposits are related to other geological features, and a prediction from that hypothesis is that gold would be found in a place nobody had ever thought to look before.

When you do dig there, and find gold, the fact that the gold has always been there (it was placed there in the distant past) does not mean that the hypothesis was not making a successful prediction. The hypothesis was not developed with knowledge of that particular gold deposit. Predictions from the hypothesis do not have to be "gold will eventually form here in the future" - it's still a prediction of you say "dig there, and I think you'll find pre-existing gold".

RedBaron at 00:32 AM on 9 October 2016

Models are unreliable

Models are always wrong. What matters is if they are skillful.

Emerging patterns of climate change

As you can see, in order to be skillful you must take what you have learned apply it to the improving models, adjust them, and then run them again to see how they match up to unknown future events. Those future events once known and giving you more knowledge, then can give you the needed information to again improve your models...which will also be wrong, but hopefully better. This continues as long as you are learning because of skillful models, they will keep improving.

So this idea that you can't go back and see if the new improvements fit old data (hindcasts) is categorically false. Of course you need to go back and match it up to old data. That's how you determine if the new adjustments to the model are skillful.

In other words it's a process. It will never be perfect, but it should gradually trend towards the models becoming better over time.

Dikran Marsupial at 20:52 PM on 8 October 2016

Models are unreliable

Just to add, what Nate Silver is really talking about is "in sample" predictions and "out of sample" predictions. It is an "out of sample" prediction if the thing you were predicting is not part of the data used to calibrate the model. If I calibrate the model on the data from 1950-present and use it to predict what happened from 1900-1949, then this is still a prediction from a statistical perspective, even though it is predicting something that ocurred before the calibration data. The key point is that you can't overfit "out of sample" data.

HTH

Dikran Marsupial at 20:48 PM on 8 October 2016

Models are unreliable

FrankShann the Nate Silver article is missing an important point. If I construct a model and fix its parameters and then observe the eruption of Mt Pinatubo, the eruption is still in the future from the perspective of the model as the parameters of the model had already been fixed. This is true even if I don't generate the model runs until afterwards. In this case, the model cannot possibly be overfitting the response to pinatubo (as the parameters were already fixed), and hence Silver's criticism is not relevant. Similarly, the CMIP projects archive model projections (understanding the difference between a projection and a prediction is much more important), so if we compare what the models say about climate after they were archived, that is still a prediction.

So we could say that "the model would have predicted the response to Pinatubo had we known in advance the details of the eruption", but this is a bit verbose, and most people are happy just to view it as bing a prediction from the perspective of the model.

Essentially overfitting is only a concern if you have tuned the model in some way on the observations you are "predicting" (this does happen in statistics/machine learning, I even wrote a paper describing a common, but not widely understood, way in which it can creep in, and what to do about it).

FrankShann at 18:34 PM on 8 October 2016

Models are unreliable

" A sign that you're spending too much time in model land is if you start to use the word 'prediction' to refer to how you model past data ... It is very easy to overfit a model, thinking you have captured the signal when you've just described the noise. Sticking to the simple, commonsense definition of prediction as something that applies strictly to a future event may reduce the risk of these errors." Nate Silver. The Signal and the Noise. New York, Penguin, 2015:452.

And sticking to the simple, commonsense definition of prediction as something that applies strictly to a future event will also reduce the risk of being misunderstood by the general public.

KeenOn350 at 15:56 PM on 8 October 2016

Pew survey: Republicans are rejecting reality on climate change

Seems to me almost all politicians in the world are "rejecting reality" - everyone is still talking "economic growth" and "job creation" - and "natural gas as a bridge" to renewables. Just that Republicans are more extreme - living in la-la land instead of fantasyland like everyone else!

nigelj at 09:04 AM on 8 October 2016

The future belongs to clean energy

Wind intermittency is sometimes claimed to be a problem, but is less challenging than it appears.

cleantechnica.com/2013/08/12/intermittency-of-wind-and-solar-is-it-only-intermittently-a-problem/

The article says the following "The UK’s National Grid reports that only 22 GWh of fossil fuel reserve power was needed to back up the UK’s 23,700 GWh of wind electricity when there was no wind at all to harvest. This is partly because the wind is always blowing somewhere on the seascape or landscape—quite often, not far away—and thus wind power can always be sent from there to the towns and cities where there is less wind or no wind at all"

I think it's astonishing how little fossil fuel backup power is required, so the resultant emissions become a small concern, - although not ideal. Of course an alternative approach would be to have additional surplus wind energy, or other forms of backup power. Presumably the challenge would be very small countries where the entire country could be under an anticyclone with little wind, on some days. This would require specific approaches for such a country.

But remember, fossil fuel grids and nuclear have very substantial surplus capacity as well, due to maintainance requirements.

ianw01 at 08:04 AM on 8 October 2016

The future belongs to clean energy

michael sweet @7: Thanks for the detailed and thoughtful reply. I doubt we'll be able to solve Ontario's mess here. I will spend some time looking into the links you provided. Allow me to pick up on some points you raised:

The 7 day chart often nicely displays the irregularity of the wind generated portion of Ontario's electricity. When it does not contribute, other sources must make up the shortfall.
Ontario's installed wind generation capacity is ~3900 MW, and it is currently generating about 800 MW. At each day's peak demand hour in the last 7 days, wind generation has ranged from just 66MW on October 3 to 2332MW on Oct 5.
I have no particular love for nuclear and yes it is expensive. It is part of the problem here and a big part of the low-carbon profile of electricty in the province.

Finally, you ask what do I think you are missing. When you state "Ontario will probably be best served with their expensive nuclear until wind becomes so cheap it is economic to scrap the nuclear plants..." the thing that seems missing is recognition that wind is intermittant. You made that assertion devoid of any mention of storage or long range transmission capacity. I think it must have been implied, but it is non-trvial and must not be downplayed.

Similarly the whole original article here is a "wind power is getting cheaper" puff-piece by a CEO with a vested interest in selling more turbines, with no mention for how its intermittency can be handled. I'd much rather hear about all the great grid-scale storage technology that is being built and getting cheaper.

Sorry for the rant. This transition is important and we both want the same goal. I'll do my homework and see if I can allay my fears.

michael sweet at 03:07 AM on 8 October 2016

The future belongs to clean energy

Ianw01,

On his website Jacobson has a plan for every USA state and most of the countries in the world. How much more detailed do you want? In my opinion, it is not necessary to redo everything Jacobson has done. If a few locations are checked (as has been done in the lists of citations I have already provided) the time is better spent working on the issues Jacobson and others have identified, like power storage and hydrogen usage, rather than checking on his projections. The energy system is very large and complex. Jacobson has demonstrated many paths are available to reach the desired endpoint. The final result will not be exactly what Jacobson currently forecasts but will be completely renewable.

Checking the website you cite about Ontario, right now (12:30 pm EST), nuclear provides 11,000 MW, hydro 4,000 and wind and solar combined about 1 MW. This hardly seems like a "huge buildout" of wind. A single new nuclear power station costs $8-10 billion (if they could be built on schedule). Your issue is that nuclear (which must run 24/7, except when it closes down completely) is overbuilt, not wind. Since nuclear is the most expensive energy, that is why your energy costs are high. Do not blame wind for the wasted money on nuclear.

Nuclear requires huge fossil standby in case the reactor shuts down, which happens once or twice a year. Wind and solar do not require spinning reserve at high levels. Do not blame wind and solar for expensive reserve set aide for nuclear emergencies. I found the 7 day page hard to read. What is your point?

For storage you have already built hydro, which is the best form of renewable storage. All that is required is for the management of your hydro facilities to be adjusted to a renewable support format instead of a fossil fuel support format. This is an oversimplification, but so are your complaints of difficulty from renewables. In the new renewable energy system the grid will not function in exactly the same way as it does using fossil fuels.

Jacobson won the Cozzarelli prize, for best paper in the PNAS. In it he ran a model of the entire USA for 4 years and found that all energy is supplied all the time paper. This demonstrates renewables can supply all power on windless nights. You keep asking for work that has already been done.

In my opinion, Ontario will probably be best served with their expensive nuclear until wind becomes so cheap it is economic to scrap the nuclear plants (a few years at the current pace) or sooner if they want to switch over industries that currently use fossil heat to electricity. That change will be made in different industries as wind continues to be cheaper than fossil fuels and nuclear.

I wrote the original article you linked and used that paper in my AP Chemistry class last week as a science resource. What do you think I am missing? Since that paper was published additional data has been published (like Jacobson 2015 linked above).

ianw01 at 01:28 AM on 8 October 2016

The future belongs to clean energy

michael sweet @4: I have read much more than one study. My concern is that we can't afford to bungle the transition. The Jacobson 2015 paper covers a remarkable range of topics, and out of necessity stays at a high level. It cannot take the place of a detailed engineering plan for each jurisdiction. That further planning work needs to be done ASAP, and on that I'm sure we agree. (The citations are impressive but I maintain that citations do not consitute independently verifying the conclusions.)

Tom Curtis @5: Agreed - the need to move that way is clear. And yes, the political dimension to the challenge we face is significant. As for "viability" my main concern is the extent to which storage and interconnections can meet power demand for extended periods of low winds in a region during long cold winter nights. Sure, with "enough" storage and overbuilding of generation it can work, but to be convinced that the Jacobson vision is viable, I think that a detailed picture by state of the worst case scenario they modeled would go a long way to de-bunking critics of the 2050 vision.

If you are both still with me, let me provide an example that perhaps explains my bias and concerns:

In Ontario the government closed coal-fired generation and embarked on a huge build-out of subsidized wind generation in the province. So far so good, but it was an energy plan devised by politicians. The province now has inflexible base-load generation, minimal storage, and a high proportion of renewables whose generation (under premium-priced incentive contracts) correlates poorly with demand. That often leads to overgeneration where they have to pay to dump power to neighboring jurisdictions. That, coupled with the need to keep substantial fossil-fuel generation capacity at the ready means that tax- and rate-payers are in an uproar, the province has cancelled the next $3.8 billion of renewable generation.

This is a good web site to explore this in real-time: see the Supply tab's 7 day chart. I bet this October's windy days are going to be quite different from a calm cold night (or even daytime) in December or January.

On the positive side, Ontario's supply is largely carbon-free, as you can see from that site. Many jurisdictions would be pleased to have such a low-carbon profile for their electcity generation.

However where do we go from here? Pulling the plug on fossil fuels and nuclear generation in Ontario seems like pure fantasy. Clearly extensive storage technology is needed before further renewables are added, and the considerable issue of residential and commercial building heating remains unaddressed.

A path that is financially, politically, and technically viable to get Ontario from the present to the 2050 Jacobson vision needs some serious detailed planning, and it won't be easy.

One last request before you respond: go back and re-read the original article here that was the context for my inital post.

Tom Curtis at 17:53 PM on 7 October 2016

Water vapor is the most powerful greenhouse gas

TonyLambert @261, the effect of irrigation on temperatures has been studied a number of times. In chronological order we have Boucher, Myhre and Myhre (2004), who find a 0.03-0.1 W/m^2 global greenhouse forcing from irrigation, but a surface cooling of 0.8 K over irrigated lands. That equates a 0.02 K increase in global temperature, assuming a Transient Climate Response of 2 K per doubling of CO2, and weighting the regional cooling by area.

In contrast, Puma and Cook (2010) find an overall cooling effect from irrigation in tropical latitudes (NH winter) and tropical and NH mid-latitudes (NH summer) once all factors are included, but for land surface only:

Boucher et al also show a slight cooling for land surface only according to Puma and Cooks' table 1.

Finally, Vresse, Hagemann and Claussen (2016), which you cite, shows a cooling effect from irrigation both in Asia and Africa, but do not give global figures.

Clearly from the tables in Puma and Cook, this listing is not exhaustive.

Digby Scorgie at 13:13 PM on 7 October 2016

DOE charts show why climate doom and gloom isn't needed

From all the comments above one can see that we have all the technologies and techniques we need to make a huge dent in our emissions. Some of these technologies are already having an effect — as the article makes clear regarding solar and wind power, LEDs and battery storage. Some techniques have yet to be implemented in any meaningful way — and here I'm thinking particularly of the agricultural sector — but they could have a dramatic effect if they were rolled out world-wide. But is it happening fast enough?

There are various shades of opinion about our winning the race. Some are pessimistic, some are not. I'm more interested in learning if any modelling community has looked into this. I bought a copy of "Limits to growth" over 40 years ago and have been dipping into it more often in recent years. Their standard run predicts a collapse in about mid-century, and as I noted above, the recent reappraisal of "Limits to growth" (with 40 years of data) has us tracking the standard run quite closely.

I have heard of only one similar study and that is by Aled Jones of the Global Sustainability Institute at Anglia Ruskin University in the UK. Their model is intended for short-term projections for the insurance industry. As I understand it, just for fun (?) they ran the model to 2040 and discovered that it predicts a collapse before this date.

Are there any other modelling communities out there, and have they come up with different outcomes? The specific problem, as I see it, is comparing our rate of emissions reductions with the rate at which the climate is worsening. This was not considered in "Limits to growth". They assumed that climate effects would not be significant before we stabilized the global system, assuming of course that we actually do manage to stabilize the system.

To summarize, it's one thing to have all the building blocks to avoid disaster, it's quite another to use them.

TonyLambert at 12:54 PM on 7 October 2016

Water vapor is the most powerful greenhouse gas

This blog states: "The other factor to consider is that water is evaporated from the land and sea and falls as rain or snow all the time. Thus the amount held in the atmosphere as water vapour varies greatly in just hours and days as result of the prevailing weather in any location. So even though water vapour is the greatest greenhouse gas, it is relatively short-lived."

S. Stanley states "Agricultural irrigation is so widespread that it accounts for about 4% of the total evapotranspiration of water from Earth’s surface." (Eos.org: Research Spotlights, August 2016). Further, De Vrese et al [1] show that Asian irrigation causes a large increase in precipitation in East Africa. And Lo et al [2] and others show that California irrigation affects precipitation in the US mid-west. Considering that irrigation is fairly continuous and constitutes a fairly large source of evapotranspiration, the resulting atmospheric water vapour flows might be fairly significant in terms of their effect on atmospheric temperature, even if a particular droplet might be short lived. My question is whether you can point to a study that has quantified the effect of irrigation water vapour flows on the temperature of the atmosphere, including over the last 100 years.

[1] de Vrese, P., S. Hagemann, and M. Claussen (2016), Asian irrigation, African rain: Remote impacts of irrigation, Geophys. Res. Lett., 43, 3737–3745, doi:10.1002/2016GL068146.

[2] Lo, M.-H., and J. S. Famiglietti (2013), Irrigation in California's Central Valley strengthens the southwestern U.S. water cycle, Geophys. Res. Lett., 40, 301–306, doi:10.1002/grl.50108.

nigelj at 09:05 AM on 7 October 2016

Pew survey: Republicans are rejecting reality on climate change

We do indeed have all this evidence of substantial climate change denial among the Republicans. I accept your suggestion that their dislike of taxation and regulation leads to denial of the science.

However The Republicans appear to be strong defenders of property law, so they are not adverse to all regulation. Climate change regulations or taxes, etc, are really just a way of protecting the property of future generations, so should be acceptable to Republicans ideologically. Their opposition is very much a case of not thinking it all through.

Tom Curtis at 09:03 AM on 7 October 2016

The future belongs to clean energy

ianw01 @3, there is no question that some combination of renewable energy, energy storage at a number of time scales, and improved network capacity can completely supply the USA (or any other countries) energy needs. Whether or not that is 'viable' is a different matter, as "viable" is a very vague, indeed, a subjective word. I can well imagine that a commited climate change denier will find no such plan 'viable'; but that that is only an indication of their unwillingness to accept any conversion to renewable energy.

The interesting thing about Jacobsen (2015) is that, for the US, they show a pathway to achieving that end whose calculated costs show a net benefit across the full range of uncertainty (excluding the cost of stranded assets, and health and climate impact benefits). An actual attempt to impliment the scheme may well be less effective than it is on paper (most likely due to political factors), or be more effective (due to improved technology). But, as in any policy issue, it is not known on which side of that equation we will fall, so that means there is no technical reason not to make the attempt. And there is certainly a need to do so.

michael sweet at 07:00 AM on 7 October 2016

The future belongs to clean energy

Ianw01:

A quick search of Google Scholar shows that 42 studies have already cited Jacobson 2015. Most of those support the claims of Jacobson. That is a lot of citations considering the lead time required for a paper to get in a journal. Jacobson 2008 has over 600 citations. Many of those have similar conclusions to Jacobson 2015.

Perhaps if you read more about the subject of renewable energy you will be more supportive. When you limit your reading to a single study it appears that more work is required.

ianw01 at 05:29 AM on 7 October 2016

The future belongs to clean energy

@ 2-ajki: Hah - you had me going there. I thought you were going to say that we need some skepticism about renewables and the risks of relying on someone "talking their book" in that sector. :-P

Even setting aside vested interests, I think I could make the claim that some skepticism is in order about plans to deploy renewables (due to viability rather than motivations).

For example, one study claiming that overbuilding intermittant renewables (albeit with storage and better interconnections) and discontinuing nuclear is a viable plan for the USA is insufficent evidence that that is truly viable. The goal is laudable, the conclusion is appealing, but that does not mean that the authors may have overlooked something. The result needs to be independently analyzed and reproduced to be sure the construction of the investigation was not faulty.

That's probably enough said - I'm sure the slings and arrows are pointed my way already - but please know that I think we owe ourselves a deeper exploration of the engineering challenges to transition to a zero emissions society.

You are saying we should have a list of "myths" debunking criticisms of various CO2 mitigation or avoidance strategies? Perhaps we agree! :-)

ajki at 18:52 PM on 6 October 2016

The future belongs to clean energy

When I look at the massive commenting of the linked article [the known Guardian Blog], I'm thinking (again and again) that there is a need for a new kind of myth list here on SkS. While the "sceptics" lose more and more ground on the scientific basics of climate change, they return freshly and completely unconvinced on all fields of practical avoidance or production changes. The patterns presented in this "newer" discussions reminds me very much of the pointless discussions in the early 2000 wether there are GHG and if there are, why they are not causing any problems and if they would do, why it's not us that produce them and if it is us, then why we could never change this.

RedBaron at 16:54 PM on 6 October 2016

DOE charts show why climate doom and gloom isn't needed

You guys do know the whole cancer and nobel prize thing was rhetorical right? More specifically which is better? Improving a genome of a corn plant to obtain 10% increased yields? (and you still have to deal with all the issues associated with cropping including soil degradation and pesticide runoff and a positive carbon footprint in your cropping system etc.) Or finding a way to double yields of the final product by not growing corn at all, and making your ethanol and feeding your livestock other ways that don't use pesticides, nor degrade the soil, and have a negative carbon footprint?

This means that switchgrass ethanol delivers 540 percent of the energy used to produce it, compared with just roughly 25 percent more energy returned by corn-based ethanol according to the most optimistic studies [1]

So why do we struggle to barely break even or maybe slightly gain a little energy with corn ethanol on a good year? Because the directive from the USDA is specifically to increase corn ethanol, not ethanol from more efficient sources. It is part of the commodity markets buffer stock scheme designed to vastly over-produce corn and other grains by "destroying" the huge surplusses.

Before anyone can make any progress on this, you must first dispell the myth that our system is efficient or required to "feed the world". It couldn't be further from the truth. It is literally designed to be efficient at inefficiency, and it is not designed to "feed the world" it is designed to make a stable price in the commodity markets by "destroying" the surpluses in the most profitable way possible; so we can continue to overproduce without crashing the price below cost to produce.

In a normal economic market, overproduction drives the price down. There is no way the entire world could possibly eat all the corn soy and wheat we produce. So to keep the price up, we must destroy it. However, that also has ethical issues involved with purposely destroying food when there are hungry people on the planet. So to avoid this a myth was created that we are "feeding the world" and all these creative ways to "destroy" the surplus are the most efficient at doing so. They are not. Making corn ethanol or corn fed animals in confinement is only efficient at destroying grain surpluses, not at actually producing final product in terms of yields per acre or energy spent per calorie returned.

chriskoz at 12:40 PM on 6 October 2016

2016 SkS Weekly Climate Change & Global Warming Digest #40

Nice quote from Ken. Just replace "little old ladies" with "vulnerable countries" that do not contribute to AGW but bear most of its consequences, and you've got a true picture. Or, in temporal space, replace "little old ladies" with "future generations".

AGW is firstly a social problem, and then environmental problem. The fact that w're dealing with its denial, confirms we have a social problem here. If it was environmental problem only, it'd be far easier to fix.

Paul W at 10:47 AM on 6 October 2016

The future belongs to clean energy

Well its good news that wind is on the up. Don't get me wrong I want wind to "win" very much. When I look at the worlds 2000, 2010 and 2013 total energy and renewable energy its lifeted from 13% renewables in 2000, 13.3% in 2010 to 13.8% in 2013. (Wikipedia World energy consumption)

When I look at the need to end fossil fuel at the current rate our budget runs out in some where between 5 and 15 years if we are to keep the planet to below 1.5 C average temperature increase. Even if renewables continue to grow and I hope they grow very much faster, we are still short of what we need.

An all out war footing is still called for to very greatly increase all sustainables to displace fossil fuels.

Don Miller at 10:01 AM on 6 October 2016

DOE charts show why climate doom and gloom isn't needed

@Red Baron - re: ".....but what about the the scientist that discovers a way to help avoid getting diabetes or cancer to begin with by identifying an improvement in our food systems that just so happens to sequester carbon and improve soil health too?"

Just such a system is used in a number of countries and is remarkably effective at reducing soil erosion, retaining soil moisture and improving crop production - all the while sequestering carbon. But because it is cheap it is not held in high regard. Nobel Prize? You have to be joking.

DrivingBy at 07:49 AM on 6 October 2016

DOE charts show why climate doom and gloom isn't needed

Re #5 (this is OT, so it'll be short)

" but what about the the scientist that discovers a way to avoid getting diabetes or cancer to begin with by identifying an improvement in our food systems"

There's no rainbow nor unicorn riding it.

Type I diabetes can't be fixed by 'improvement in our food systems' because one is born with it. Type II is caused by eating too much food, with sugary food having a greater effect. The system improvement to prevent type I is eugenics (ya sure ya want that?), the system to prevent type II lies between one's ears.

bjchip at 05:54 AM on 6 October 2016

DOE charts show why climate doom and gloom isn't needed

@9 RedBaron

food-per-capita:

current projections are based on current energy availability and pricing as it impacts both the farming community and the shipping of food.

current projections are based on a climate that does NOT change drastically.

With BCCS (note to moderator .NE. Bio-Carbon-Capture and Beijing-Climate-Center ??? ) things can improve markedly but have you ever tried to change a traditional farmer's mind? :-) .

Of course, if we can pay him for the Carbon he pulls down... ;-)

I remain pessimistic because we have German Greens in league with US Republicans in the unwitting effort to pitchfork children of coming generations onto bonfires of delusional thinking. In 15 years the next generation will see the results and the result will be revolt. People blocking action will be peacefully removed from power, or will be forced to flee, or hurled with great force from their obdurate positions.

Yet it will still be far-too-late. The actions required are required now.

When Mother Nature starts smacking mule-headed humans between the eyes with the 2x4 to get their attention, the time is long past for the result to be merely bad.

John Hartz at 05:40 AM on 6 October 2016

DOE charts show why climate doom and gloom isn't needed

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