back to article More and more likely that double CO2 means <2°C: New study

The results of a new approach to calculating the effect of CO2 - using empirical observations - suggest it has a lower impact on the climate than previously thought, and its effects are being over-estimated by the IPCC. Publishing in the American Meterological Society's Journal of Climate, a new paper called An improved, …

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Well done in anchoring models to actual observations.

I'm very surprised however that GCM's don't use actual data from actual weather stations historical records as seeds for the start of a run.

As in all things climate related it's not just the worst case but the probability of that case (and them most likely value) that matter, and probability density functions in this case do not seem to be the nice bell curve beloved of mathmaticians.

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Anonymous Coward

Re: Well done in anchoring models to actual observations.

"I'm very surprised however that GCM's don't use actual data from actual weather stations historical records as seeds for the start of a run."

They do, on both counts.

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Anonymous Coward

Re: Well done in anchoring models to actual observations.

They don't, on both counts.

GCMs attempt to do something called hindcasting. They set up the inputs the way they were at a point in time in the past and then run the model forward attempting to simulate past climate. When doing this they don't take the temperature from, say, Geenwhich and another from Heathrow as inputs. Instead they will use a gridded dataset such as GISS or HADCRUT. These datasets take the data from individual weather stations and apply multiple adjustments before using them to calculate the temperature of a gridcell.

The GCM's never see the data from an actual weather station.

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Re: Well done

Well done for a sensible article, especially this:

"Very few people disagree with the basic fact that the greenhouse gas CO2 warms the climate"

It's equally stupid to deny greenhouse effect, which is pretty basic physics, as it is to project remote worst-case scenarios as being likely / guaranteed, and then run around panicking like chicken little tinking the sky is falling on your head.

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Re: Well done

No one has ever denied that CO2 affects climate: that was an invented slur by the warmists.

The argument was always whether it was

1/. Detectably relevant

2/. If (1/.) in any way man made.

3/. If (1/. and 2/.) serious enough to warrant political action.

The answer to 1/. appear to be 'probably, just'

The answer to 2/. appears to be 'probably, just'

The answer to 3/. appears to be, 'no not really'

And by the way, the answer is NOT basic physics. Its very complicated physics, as there are many many feedbacks inherent in the system,

Not the least of which complexities, is that what we as a species are most concerned about is surface temperature, sunlight and rainfall, because that drives agricultural policies. And sea levels.. We don't actually care if the stratosphere suddenly warms two degrees in isolation because we don't live there.

ALL of the consensus is now shifting from 'stop emitting at any cost' towards 'be prepared for slow gradual changes in the ecosphere, whose outcome we cant actually predict with any certainty whatsoever'.

I.e. all the money wasted on CO2 reductions is ...er money wasted on CO2 reduction.

WE have a far more serious problem in that we are running out of CHEAP primary energy sources, and 'renewable energy' so called hasn't a cat's chance in hell of replacing it

The only actual hope is transition to a nuclear electric society, and that in itself is a bugger of a problem.

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Re: Well done

Greenhouse gasses certainly aren't ZERO towards global warming.

The major question is...

How much do they contribute? How much value is there in significant efforts to reduce it? How sure are we that NOTHING else contributes to the observed warming?

This Euro-Zeitgeist needs these answers before we follow it into the woods...

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Re: Well done in anchoring models to actual observations.

"GCMs attempt to do something called hindcasting. They set up the inputs the way they were at a point in time in the past and then run the model forward attempting to simulate past climate. When doing this they don't take the temperature from, say, Geenwhich and another from Heathrow as inputs. Instead they will use a gridded dataset such as GISS or HADCRUT. These datasets take the data from individual weather stations and apply multiple adjustments before using them to calculate the temperature of a gridcell."

I suspected it was something like this but reading the article certainly did not give that impression. A lucid explanation Mr (or Ms) AC.

It's still odd to me that model grids are not aligned to weather station locations. Obviously some of them have moved over time (possibly by quite a lot) but some of them should have stayed more or less in the same place. Yes I am aware of the "heat island" effect.

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FAIL

Re: Well done

"2/. If (1/.) in any way man made."

"The answer to 2/. appears to be 'probably, just'"

Simply wrong. All of the atmospheric CO2 increase is man made.

We know this because our emissions are *larger* than the atmospheric CO2 increase.

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Re: Well done

"We know this because our emissions are *larger* than the atmospheric CO2 increase."

Which proves there are other processes at work that neutralise man-made emissions. It doesn't prove that there aren't other processes that also release CO2 that are also being partially neutralised by these processes.

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Re: Well done

Logic fail.

You're claiming

atmospheric increase = our emissions - taken by carbon cycle + unknown emissions

But we know that

our emssions > atmospheric increase

so

unknown emissions < taken by carbon cycle.

so all of the increase is due to our emissions.

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Carbon dioxide

The other day my daughter aged 10 came to me saying: I'm glad I won't live for a hundred year. Why? I asked her. "Because the world is going to be destroyed by CO2 and we won't have anything to eat and the land will be flooded by the sea and it will be terrible". "Don't worry about the CO2" I told her. "When I was 10 years old (more than 30 years ago), I was coming home from school scared and telling my parents that we were soon going to have another ice age, everything would be freezing cold, we were all going to die, and on top of that, the oxygen and the water would be running out soon anyway. Plus the Chinese were going to invade any moment. The things they teach kids in school, eh! No wonder education is compulsory.

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Black Helicopters

Re: Carbon dioxide

You have to love our educational systems. They'll teach you how to be a good little slave of the state, but they cannot teach you how to succeed, nor how to think. Just believe whatever version of the truth they tell you. That is all.

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At 2C per doubling of CO2, even 1.5C, the problem is less, but still exists. It doesn't limit us to 2C warming because we aren't limited to only doubling CO2. Doubling would mean elevating CO2 level to 560ppm (compared to the preindustrial 280ppm level). But there's enough coal, oil, shale gas and other proven reserves of fossil fuels to lift CO2 much higher than 560ppm. Possibly even above 1000ppm. On top of that are other greenhouse gases like methane, nitrous oxide, sulfur hexaflouride which are also increasing. Bit players, but they still add on the equivalent of a few hundred ppm CO2 in the end.

I would guess that business as usual would be capable of leading to at least do two doublings of CO2 (to 1120ppm), which even if we assume 1.5C warming per doubling means 3C warming.

To put that in context, global temperature of the last 10,000 years is thought to have been varied within a range of 1C.

It would be nice to at least have some acknowledgement from the climate skeptics that these numbers make CO2 the primary driver of climate. It can no longer be thought as some irrelevant bit player when the warming it produces is greater than historical variations.

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@Nom - true, and we should not be complacent about the issue, rather, we should be able to take steps that are proportional to the problem. For example, reducing methane, nitrous oxide, sulfur hexaflouride are easier wins than cutting down CO2. Fracking is being championed as produsing gas that reduces dependency on coal and reduces CO2, but also releases a lot of methane, and depending on how well-sealed or not th eweel is, can produce a worse overall effect.

We need on work on reducing total greenhouse effect, instead of concentrating only on CO2

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Anonymous Coward

At an increase of 2ppm/year (which is what it is at the moment) it will take 80 years to reach 560ppm and 300 years to reach 1000ppm. If you want to use an accelerating increase of CO2 then that looks to be 1ppm/40 years which means it will take 59 years to reach 560ppm and 153 to reach 1000ppm. The indications are that the Western countries that have already industrialised have plateaued (fallen in the USA) with their output of CO2 and the same should happen with China. It is unlikely to take China (the main culprit) more than a few decades to fully industrialise which means that any acceleration should stop and the amount of CO2 in the atmosphere level off well below 1000ppm (and probably below 560ppm).

> To put that in context, global temperature of the last 10,000 years is thought to have been varied within a range of 1C.

Depends entirely upon which reconstruction you use. One thing most of them agree on is that most of the past 10,000 years were warmer than today. Another problem with the reconstructions is the resolution. Nearly all are low resolution which results in the peaks and troughs being smoothed and leads to narrowing of the temperature range. Other proxies, such as ice cores, have problems with diffusion which will also level out the peaks and troughs.

> It would be nice to at least have some acknowledgement from the climate skeptics that these numbers make CO2 the primary driver of climate. It can no longer be thought as some irrelevant bit player when the warming it produces is greater than historical variations.

The only evidence CO2 is the primary driver is in the GCM's. It might turn out to be a primary driver but so far there is no proof of that. The longer the hiatus in temperature increase goes on, the smaller the role of CO2.

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The problem is that we really just don't know. ISTR it was a Dutch scientist a while ago who worked out that CO2 in the atmosphere allows the Earth to hold on to heat energy from the sun. It was other people who said that there was a massive positive feedback mechanism, and quoted all sorts of things that would cause temperature to spiral to Venus like levels and perhaps lead would melt on the surface on the planet, like at Venus.

However, people have done scientific studies on the individual statements of how the positive feedback works, and found that not all of them were positive. The problem is that we really have no idea. If the Earth has had a climate with global temperatures with 1°C for 10,000 years, then perhaps we should wonder if there are a number of negative fedbacks.

For me, I think the climate models are like a drunken walk home. Heading generally in the right direction, with corrections added every few months as more knowledge about affects on the climate are known. Generally we are heading towards a more accurate model, but it seems at any particular time we might be heading away from the correct route. As long as people recognise this, and devote energy into improving our knowledge that is OK. But to put e.g. 95% on a model based on guesswork because we don't know yet, which then gets presented as 95% fact in the press or to politicians without stating what it assumes/ignores is dangerous IMHO.

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Per doubling

@nomnomnomnomnomnomnom

I think that the relationship between CO2 and its direct heating effect is logarithmic, so the base rise expected from the second doubling of CO2 will be much much less than the second. What feedback will add to it, who knows?

You ask sceptics to accept that co2 is the main driver of warming. I'm not prepared to do that until there's more research that provides a better quantification of anthropogenic effects such as land use change, aerosols and soot pollution as well as some other non anthropogenic causes like cloud formation. Once we have more reliable data for these, then I'd be happy to accept that we know exactly what's going on with the climate system.

It is becoming apparent that we were misled during the late 90s and the early part of this century. A lot of people made predictions that have been shown to be false. We were *assured* that the science was settled and government policy changed as a result. Well, now we that that the science isn't settled.

When someone produces a verifiable explanation for the divergence of measured surface and tropospheric temperatures from model predictions I will be more impressed. Then, someone will also have to explain to me why, when the science was settled, we need this new explanation at all...

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Re: Per doubling

multi-response follows

>>"Depends entirely upon which reconstruction you use. One thing most of them agree on is that most of the past 10,000 years were warmer than today"

I only know of one reconstruction and temperature records from ice cores. Both suggest most of the past 10,000 were cooler than today.

>>"I think that the relationship between CO2 and its direct heating effect is logarithmic, so the base rise expected from the second doubling of CO2 will be much much less than the second."

Warming being the same for the first and second doubling IS logarithmic.

>>"The only evidence CO2 is the primary driver is in the GCM's."

This study that reports a "90 per cent confidence in a range of 1.2°C to 2.2°C" per doubling of CO2. There was less than 1C warming over the 20th century so a substantial part of that warming must have been due to the CO2 rise according to this study. Given everyone seems to agree CO2 levels are going to at least double, it means the study is saying humans will be responsible for at least 1.2°C to 2.2°C warming. That would mean human CO2 emissions are the dominating driver of global temperature over this period.

The question is do skeptics really accept this study or not.

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FAIL

"these numbers make CO2 the primary driver of climate."

EPIC FAIL. These numbers are obtained by ASSUMING that CO2 is the primary driver of climate.

If for example some hitherto unknown thing is driving climate, like cloud cover and so on, it makes CO2 a minor player of no significance whatsoever in the grand scheme of things.

If for example, the earth surface temps are controlled largely by a negative feedback of water vapour convection and clouds, then sensitivity to CO2 might be less than half a degree, and what is more relevant is anything that affects that feedback system. Like aerosols, maybe cosmic rays and so on..and the key factor MIGHT be to emit more or less particulates. Or point particle accelerators at the sky.

All that this has done is bang in yet more data into the 'assume its CO2' model and get a lower sensitivity, to align with the lower recorded temperatures. Only when it start to cool with rising CO2 will we be able to say that the probability is that CO2 by itself has almost no effect on climate at all. It was all coincidence and a drive for profit that created the global warming scare in the first place.

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Re: Per doubling

well if I were to say to you that are obese fat and sugar guzzling society has in fact a life expectancy double the Victorian age, would you then accept that high levels of consumption of fat and sugar were in fact the 'primary drivers of increased longevity'?

If not then you are using precisely the same logic.

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Anonymous Coward

Re: Per doubling

> I only know of one reconstruction and temperature records from ice cores. Both suggest most of the past 10,000 were cooler than today.I only know of one reconstruction and temperature records from ice cores. Both suggest most of the past 10,000 were cooler than today.

Which one? There are many of them. Which cores did they use? NorthGRIP, GISP2, Dye 3, EPICA, Dome F, Vostok, Dome C? Please point to the paper that the reconstruction is from.

> This study that reports a "90 per cent confidence in a range of 1.2°C to 2.2°C" per doubling of CO2.

That range is dependant on the MIT 2D model

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So this doubling will conclude about the year 2100, the next doubling will take 200+ years.

Human population growth is already slowing, will peak in 30-40 years, and will begin a long, slow decline. By the year 2200 there could as few as one billion humans meaning of course few cars, power plants and all the rest.

AGW is a non problem. So relax already.

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Re: Per doubling

Skeptic 1: "EPIC FAIL. These numbers are obtained by ASSUMING that CO2 is the primary driver of climate."

Skeptic 2: "That range is dependant on the MIT 2D model"

This is an interesting bit of climate debate psychology. The above quotes are from climate skeptics throwing this study under the bus. Strange all round the internet I see skeptics promoting this study, so what's happened here?

Answer is that the study provides a RANGE "90 per cent confidence in a range of 1.2°C to 2.2°C" per doubling of CO2. Climate skeptics are keen to promote that upper limit as evidence warming is less than thought. For example this article is titled "More and more likely that double CO2 means <2°C: New study". That's perfectly valid.

But what about the unspoken lower limit of that range? Couldn't we write a similar headline "More and more likely that double CO2 means >1.4°C: New study". Yes we could, because the paper provides a range, not a single limit. If the study is evidence for the upper range, it's also evidence for the lower.

But, skeptics are loathe to accept there's any evidence for a substantial lower limit, because the implications of a lower limit of eg 1.4C is that human CO2 emissions are driving global temperature and recent warming is largely human CO2 caused.

So the reaction is to attack the study. Which is odd because they never attacked the study when the upper limit was being promoted! What they want is to be able to go around claiming doubling CO2 could just as likely have a negligible tiny irrelevant effect (eg ~0.1C) on global temperature. They don't want to have to accept there's evidence that CO2 (in the modern day) is the driver.

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Happy

Logarithmic response

Might be possible under the very unlinkely scenario where carbon uptake does not respond accordingly. Even so, the relation is logarithmic, so with the last doubling we are already converging on a asymptotic maximum. Not sure what that would be, but if feedbacks are as little as these approaches indicate, and it is the pure CO2 driving the warming with the next doubling, it does not seem that it would amount to much. So relax, it won't be so bad

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"Mere 2ppm"?

I'm generally with Orlowski and his climate realism, but even I would baulk at calling 2ppm CO2 rise on a total of 390 (up from a pre-industrial 280 average) a "mere" rise. That's a pretty big number and I think you betray your prejudices by calling this "mere". Keep posting the articles, but I think you'd be a lot more persuasive if you actually acknowledged one of the few properly measurable numbers in climate science with less pejorative language.

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Re: "Mere 2ppm"?

If the 2ppm per year remains the same, that means it'll take roughly 200 years to double CO2 from today's level. Boosting the global temp by 1.5C over 200 years doesn't seem "big" to me. Certainly it seems like a problem we should be able to solve, given 200 years to work on it. Imagine if early-19th-century climate boffins had demanded of Thomas Jefferson that we stop all woods-clearing, mammal-raising, and use of whale oil and coal immediately to prevent the disastrous rise of 1C expected by the year 2010!

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Anonymous Coward

Re: "Mere 2ppm"?

Indeed - an increase of 0.5% per year (or 5% per decade) sounds like a very significant cumulative rate.

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Boffin

All the news that fits the agenda

That's all right then. Nothing to see here, move along now. It's OK to keep emitting green house gases, because they may not cause temperatures to rise at rates predicted by other studies.

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Re: All the news that fits the agenda

Glad to see you've read the article and almost understood it :-)

It's not ok to continue emitting CO2 at the rate we're doing, but it does mean we don't have to go cold turkey to get off CO2. For which we should be very grateful.

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Childcatcher

Re: All the news that fits the agenda

Quite aside from the debate on CO2 causing or contributing to climate change, it seems to be having an adverse effect on our oceans.

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Boffin

Re: All the news that fits the agenda

My point was that it's always possible to cherry pick the science you report on, to further an agenda. Here's a video (so you should be able to understand it), which doesn't cherry pick:

http://www.youtube.com/watch?v=RInrvSjW90U

You may not be so confident that there is no urgency to reduce emissions fast after watching that. Alternatively, here's the reason why it's vital to keep pumping out the CO2:

http://www.guardian.co.uk/commentisfree/2013/apr/21/carbon-problems-financial-crisis-hutton

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Holmes

"over-estimated by the IPCC"

No shit. They have lifestyles to pay for.

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Anonymous Coward

IPCC?

I'm amazed the Independent Police Complaints Commission is taking such an interest at all.

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Re: IPCC?

Well you see, the global climate was just helping us with our enquiries, when it accidentally fell down 2 flights of concrete stairs... What do you mean our police station only has one storey?

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Re: IPCC?

the 1st floor just is`nt used, all the fat cops cant climb the stairs unless theres a donut machine at the top

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Anonymous Coward

Didnt see that coming

Wait, are you suggesting the people claiming we are all doomed are like all those who have gone before? These people who have (through complicated process and little evidence) divined the great plan and know the future with pretty pictures of the end (this time a graph instead of hellfire) surely have the answer. My psychic told me so.

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One of the better articles from AO. Study confirms one end of IPCC range largely correct! Who would have thought it...

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Low sensitivity is just great

Because it gives us time to deal with the problem rather than having to cram all of our abatement into the next decade as some loons keep telling us we must do.

Two things.

1) Who thinks that in 50 years time solar cells, fuel cells, thorium reactors etc, are going to be anything like as expensive as they are now? Quite, so, if we've a few decades to change our ways this is good for us. We get to install these things when they become cheaper. And we've got all sorts of people telling us that solar is going to be cheaper than coal any day now (I think perhaps a decade but that's just an opinion). so, we can all install it when it is cheaper and then the problem's over, isn't it?

2) It enables us to work with the capital cycle. Ripping down power plants we've already built makes us poorer. When they run out, as they of course will, we'll have to replace them with something or other. If we've a few decades to deal with all of this then we can, instead of junking a lot of what we've got (making us poorer) simply insist that the new stuff we build in the future is low/non-carbon whatever.

This is essentially the William Nordhaus view of the whole subject and he's pretty much the economist who has been calling it right for the past 20 years.

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Use of observations is...

...a new innovation (never mind the redundancy)?

Gee, who'd 'a thunk it? (Julius Sumner-Miller)

So what does that say about the older ways? Hmm?

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No-feedback sensitivity

That discussion you linked to appears to be someone who's being skeptical about the Stefan-Boltzmann law.

Denying basic physics is a bit much, even for climate skeptics.

1C per doubling is the straightforward number, which gets the temperatures of the moon, Mars, Venus and Mercury right (a useful observational check on the theoretical physics).

The feedbacks have always been the toughest part of the climate models.

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"The objection to short-term measures is that renewable sources of energy are not currently economically viable"

short term = a motor on a 6.5Mw wind turnbine, and having a 10 acre field with 100 of them in mini silos

long term = the same dynamo would be generating 100Mw every minute in 20 years tops

so on and so on, along with all cargo ship conversions, not needing any diesel for combustion electric electric generators

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FAIL

I love people who deny the basic laws of Physics...

>short term = a motor on a 6.5Mw wind turnbine, and having a 10 acre field with 100 of them in mini silos

Indeed, because that's all the energy there is in the wind,

>long term = the same dynamo would be generating 100Mw every minute in 20 years tops

Only if its coupled to a nuclear power station. and '100Mw very minute' means nothing anyway.

First it ought to be 100MW, and secondly that's a measure of continuous POWER power. 'Every minute' is meaningless.

So once again the fantasists of renewable energy deny the basic laws of physics/.

Hint: there isn't any more energy IN the wind, and if you start pulling gigawatts out of upper level winds you will be fucking with climate a hundred times more than CO2 (allegedly) does.

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Re: I love people who deny the basic laws of Physics...

and so on. its nothing todo with physics, its just a delayed loop back,. when the dynamo is above the minimum RPM for generating electric, the electric goes into the "battery" and 2% of it loops back to the motor, while the rest goes off to the main grid

its alot more renewable then wind farms costing billions to build or dams. and all the infrastructure for gas pipelines etc etc etc

you can put them anywhere you like,. and there are millions of ships using billions of gallons of diesel just to generate electric which can all be converted to use 6.5Mw wind turbine with a direct drive motor on, cutting down billions of co2 whatevers

wind farms only work when there is wind, they generate 4% of power to the national grid, if all dynamo were in use with a constant source of power that is generated by using a electric motor instead of wind, tey would add 20% + and the RPM would be able to be controlled by the power station

the germans have 10Wm wind farm turbine, as long as wind farms are the aim, then weight of the dynamo will always play a part in how much can be generated

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Re: I love people who deny the basic laws of Physics...

Pardon?

Are you saying what i think you are?

i do hope not

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Re: I love people who deny the basic laws of Physics...

i have said it a million times.....

if you have a setup like this http://s24.postimg.org/wvt4f8qt1/generator.png where the electro magnet motor turns the axle of a direct drive dynamo

1>the fully charged battery is used to start up the loop and as the motor turns up to the dynamo`s minimum generating RPM, it uses most of the power in the battery

2>once the dynamo has reached itts minimum RPM for generating power, it recharges the battery and makes the motor become faster, because it uses a small amount of power

3>the motor uses alot less power then is generated when the dynamo is at its maxium generating RPM

it has nothing todo with physics, you just need a external power source to start them up, once they are at the maximum RPM for the dynamo, they can easily be perpetual

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FAIL

Re: I love people who deny the basic laws of Physics...

"it has nothing todo with physics,"

You can say that again.

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Re: I love people who deny the basic laws of Physics...

I have many times, once it gets going its just a delayed loop

its the source of infinate endless power as long as theres atleast a star to solar charge a dead battery if the dynamo is to big for a whined up charge

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Anonymous Coward

Re: I love people who deny the basic laws of Physics...

You are extracting the dilute urea solution, aren't you?

Five minutes with a hand cranked dynamo and you will discover that you have to put more energy in than you get out. Otherwise, I would not need to put petrol in my Prius - in which one motor can indeed drive the other as a generator, to give an infinitely variable drive.

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Anonymous Coward

Re: I love people who deny the basic laws of Physics...

It seems that Eadon is not the only one that needs the frog pills...

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Joke

Re: I love people who deny the basic laws of Physics...

Hi, I'm your friendly local Greenpeace eco-terrorist hippy, and I'm here to say BAN ALL OF Zmodem's WIND TURBINES!!! because they are a menace to flying pigs.

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