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Where is the heat going? Ken Perrott Dec 22

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prod_1386860363ns071213

It is a good article but a lousy headline.  The December 7 issue of New Scientist has a cover head-line Climate showdown: Is it time to stop worrying about global warming? That will create the wrong impression among those many people who get no further than headlines. And it certainly doesn’t convey the message of the article itself.

The article does acknowledge that “the average surface temperature of the planet seems to have increased far more slowly over [recent years] than it did over the precious decades.”

But says:

“This doesn’t mean that climate change has stopped, any more than the very rapid warming seen in the 1990s meant it had accelerated.”

Several reasons

The article a describes several reasons that help explain the current situation. To do this it stresses “it helps to think about heat energy rather than temperature.” In summary:

“In terms of heat. There are three possible reasons why the Earth’s surface temperature hasn’t increased much recently”

  1. Less heat arriving from the sun. “The sun’s heat output rises and falls in an 11-year cycle and measurements by spacecraft such as SOHO show it did dip particularly low recently.”
  2. Increased levels of sulphur aerosols in the atmosphere could have reflected more of the sun’s heat back into space. “Levels of sulphur dioxide have risen in the past decade, mainly due to lots of small volcanic eruptions.”
  3. More of the heat gained by the planet “ends up somewhere other than the lower atmosphere, whose temperature we focus on.”

Ocean – the main culprit

The article points out the most likely storage place for this heat is the ocean.

“Water covers more than 70% of the planet and the stuff has a huge capacity to absorb heat: around 3000 times as much energy is needed to warm a given volume of water by 1°C as is needed to warm the same volume of air.

“Observations show that a whopping 94% of the heat energy gained by the planet since 1971 has ended up in the oceans, with another 4% absorbed by land and ice. . . . So all the surface warming since 1971 is due to just 2 per cent of the heat. If just a little more heat than usual has been going into the oceans, it will have had only a slight effect on ocean surface temperatures, because of water’s huge capacity to absorb heat, but a large effect on atmospheric temperature. And several studies show that the oceans have indeed been soaking up even more heat than normal.”

The article goes on to suggest this is because there have been lots of La Niňas (which cause the Pacific to soak up heat – thus cooling the planet) lately but no major El Niňo (which extract heat from the Pacific to the atmosphere and warm the planet) for the past 15 years.

The graphic from the article illustrates where the heat has gone.

energy

The whole process is obviously complicated and there are various opinions among climate scientists about the relative importance of the different processes distributing heat. There is even a suggestion “that soaring aerosol emissions from China may have contributed to the slowdown” of surface temperature increases. However:

“the mainstream view expressed in the latest Intergovernmental Panel on Climate Change report is that about half of the surface slowdown is due to the oceans, and the other half due to the sun and extra volcanic aerosols.”

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Pseudosceptics are at it again – misrepresenting and attacking climate scientists Ken Perrott May 16

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I have already mentioned the irony of a failed politician attacking climate scientists, accusing them of treating science like a religion while declaring his own faith that:

“The world stopped getting warmer 17 years ago. That’s incontrovertible.”

(See “Incontrovertible” is it, Rodney? and Confusion and distortion – has global warming stopped?).

But another factor in this sordid little story was the way that Rodney Hide attempted to portray New Zealand climate scientist Dr James Renwick as a religious fundamentalist in his science. Basically he did this by misrepresenting Renwick – Hide told a porkie.

Hide claimed that Renwick “was in no doubt that man-made global warming was causing the summer drought” and went on to give this quote as “proof;”

” . . climate change, global warming. Put more greenhouse gases in the atmosphere and things warm up.” The host Corin Dann double-checks: “And you’re of no doubt of that?”

“Oh, no, no. There’s no other explanation that’s remotely plausible.”

Hide then went on to declare:

“That’s religious zealotry in action. Science is never that certain.”

Creating the impression that Renwick had “no doubt” that greenhouse gases were responsible for New Zealand’s recent extreme drought.

Problem is – at this stage of the interview the drought had not even been mentioned.

Interview transcript

Here’s the transcript of the interview from its beginning to Hide’s quote:

CORIN DANN: Good morning, Dr Renwick. How are you?

DR JAMES RENWICK: Good morning, Corin. Very well.

CORIN: Listen, thanks for coming on the show. I know you’re literally just back off the plane this morning. Tell us what is happening to NZ’s climate. Paint us a picture of what’s going on.

JAMES: Well, like the rest of the globe, NZ’s climate is warming up gradually. Temperatures have risen by the best part of a degree in the last century, and they’re set to rise by two or three degrees or maybe even more over the course of the coming century.

CORIN And this isn’t some normal- What is this? Is this climate change at work?

JAMES Yeah, it is. Yeah, climate change, global warming. Put more greenhouse gases in the atmosphere and things warm up.

CORIN And you’re of no doubt of that.

JAMES Oh, no, no. There’s no other explanation that’s remotely plausible.

Full transcript available at: Lack of govt leadership on climate change – Renwick

Simply a clarification that New Zealand’s climate is part of the global climate and that greenhouse gases contribute to global warming. The New Zealand drought had not even been mentioned at this stage.

The informal confidence Dr Renwick expressed was  consistent with the current understanding of the role of greenhouse gases in global warming – not, as Hide and fellow pseudosceptics and climate change deniers have claimed, that greenhouse gases were the direct cause of our recent drought.  That claim was a complete misrepresentation, clearly motivated and knowingly dishonest as the perpetrators also had access to the transcript of the interview.

Should Renwick have any doubts on role of greenhouse gases?

Dr Renwick did display, informally, a high degree of confidence that greenhouse gases are contributing to climate change. But that is hardly surprising because that is the current understanding of most climate scientists. Consider what the Intergovernmental Panel on Climate Change has said.

The figure below shows the results of simulations of global temperature from 1900 to 2005. Figure a included all the natural and anthropogenic influences.  The black line is the actual measured global temperature anomaly (obtained by subtracting the average temperature for 1901 to 1950).  The individual simulations are shown as thin yellow curves. The red line is the multi-model ensemble mean (see Figure 9.5 – AR4 WGI Chapter 9: Understanding and Attributing Climate Change).

Figure b is a similar plot using simulations which consider only the natural influences on climate. The individual simulations are shown as thin blue curves. The thick blue line is the multi-model ensemble mean.

So, climate scientist have considered both natural and anthropogenic influences. And they are unable to reproduce the global temperature changes since 1970 unless anthropogenic influences are included.

That is why the IPCC has concluded that there is a high probability (>90%) that human influences are contributing to the current observed global temperature increase.

Notice also that the experts talk about probabilities. It’s a complex field and things are rarely cut and dried. We are more certain about some influences than others. And the IPCC doesn’t hide this fact – far from it. It doesn’t make sweeping claims in the way that some of their opponents do.

I am sure Dr Renwick accepts this – his comment “Oh, no, no. There’s no other explanation that’s remotely plausible” is simply an informal recognition  of that.

While on the role of greenhouse gases this short video provides some of the data supporting current scientific assessment – in this case not relying on computer models or the IPCC.

Was our recent drought caused by CO2?

Later in the interview Renwick did comment on our drought. Here’s the relevant section of the transcript:

JAMES: Well, no, I don’t think panicking is very helpful.

CORIN : But it feels like that with this drought, though, doesn’t it?

JAMES: It’s a pretty exceptional event, yeah. It’s probably the first time in 50 years that it’s been this dry over this much of the country. So, sure, it’s exceptional. You know, a farmer would only see this once in a working lifetime.

CORIN: But if we’ve only seen it once in 50 years, should we not be that worried? That suggests it’s not going to happen for another 50 years.

JAMES: Well, the way the climate’s changing, the likelihood is that summers will become drier, so what’s a one-in-50 year event now will be, say, one in 20, one-in-25 year event by the middle of the century. And in some parts of the country, it might be a one-in-five year event by the end of the century, which means the farming sector’s going to have to adapt to that. We’ve got time – it’s decades we’re talking about, and farmers are very adaptable, but things will have to change.

Again, I think Renwick was just informally conveying what seems to be the current scientific assessment of the role of global warming in extreme weather events, like New Zealand’s drought and US storms. This is that one can’t prove a direct link of atmospheric CO2 to single specific events. However, scientific analysis analysis suggests that such events will become more frequent as the planet warms.

As Dr Renwick expressed it - “what’s a one-in-50 year event now will be, say, one in 20, one-in-25 year event by the middle of the century.”

Given the informal nature of such interviews I think Dr Renwick presented the scientific assessment pretty accurately. But of course this won’t stop the pseudosceptics and climate change deniers. Most of these, and certainly Rodney Hide, have a ultraconservative political agenda. They commonly paint scientists as plotters and schemers, part of an evil world-wide conspiracy wanting to bring in a One World Government. And claiming scientists have manipulated global temperature records to create false evidence for fclimate change.

And, yes, despite the availability of the interview transcript local climate change pseudosceptics are still misrepresenting Dr Renwick’s statements. (see Hide sticks it to Renwick and Renowden a scaring warmist). They are studiously avoiding the transcript and instead interpreting reporter’s comments.

And, of course, sticking the boot in while they are at it.

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Confusion and distortion – has global warming stopped? Ken Perrott May 14

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There’s a mantra circulating at the moment claiming that global warming “stopped 17 years ago.” It is of course being pushed by the pseudosceptics in the climate denial echo chamber. However, even people who should know better have been heard to repeat something like that.

Rodney Hide, a former New Zealand ultra conservative politician has assured us “The world stopped getting warmer 17 years ago. That’s incontrovertible” (see my post “Incontrovertible” is it, Rodney? for my take on that). And one of the commenters on my blog at  SciBlog seems willing to treat Rodney’s assurance as a simple fact. Of course the pseudosceptics proudly and loudly reassert similar claims.

But many of those repeating this mantra are attributing the claim to authoritative sources, like the the Intergovernmental Panel on Climate Change (IPPC) and leading climate scientists and institutions.

So what’s the truth. Has global warming “stopped?” Are climate scientists saying it has stopped?”

Short answer is actually no. Slightly longer answer is along the lines that the current rate of global temperature increase seems to have slowed, global temperatures may even have plateaued, but that doesn’t support a claim that global warming has “stopped!” Or stopped 17 years ago.

IPCC Chairman misrepresented

Firstly – lets deal with the use of Rajendra Pachauri, Chairman of the IPPC, as a source for this mantra. This appears to go back to a report in the Australian which claimed he  “acknowledged a 17-year pause in global temperature rises.”

Trouble is, there is no record to back up the claim and the IPCC communications office said it does not accurately represent Pachauri’s thoughts on the subject.

The only statement the Australian article actually attributed to Pachauri on this subject is that “global average temperatures had plateaued at record levels and that the halt did not disprove global warming.” And that is paraphrasing Pachauri and not quoting him directly.

As the blog Skeptical Science pointed out (see Did Murdoch’s The Australian Misrepresent IPCC Chair Pachauri on Global Warming?) if he “had he said that global surface air  temperatures have plateaued and that this doesn’t disprove global warming, he would be 100% correct.” And that is what a number of well-known climate scientists also have said. Usually no mention of 17 years and certainly no claim that global warming had “stopped” 17 years ago.

To help clarify I repeat below two figures from my recent post “Incontrovertible” is it, Rodney? These show global air temperatures for the last 17 years and for the long-term – since 1880.

17-years

Global temperature anomalies for 1996-2012 (Average annual temperature data from NASA’s Goddard Institute for Space Sciences),

Line plot of global mean land-ocean temperature index, 1880 to present, with the base period 1951-1980. The dotted black line is the annual mean and the solid red line is the five-year mean. The green bars show uncertainty estimates. [This is an update of Fig. 1A in Hansen et al. (2006).]

As I said about the first figure in my recent post:

“There’s a lot of noise so all we can say from that data is the warming rate is in the range of  -0.02 and 0.17 °C/decade (95% confidence level). That’s the problem with such short time periods.”

Putting short-term trends in context of long-term record

The data in the first figure must be put into the context of the longer term changes. And as the 2nd figure shows a number of short periods over the longer term which had a similar pattern to that in the first figure. It would be silly, especially with hindsight, to claim that global warming “stopped” in 1990, or 1985, or 1975, and so on. Yet this is what some people are doing.

It’s easy to find short time periods where the global temperature trend is not significantly different to zero – that’s the nature of a record with this sort of variability or noise. A record which also results from a number of factors and is therefore not a simple correlation with one cause.

So it is silly to cherry pick a short period and then make an absolute claim (global warming has stopped) – and especially to claim that somehow something happened in 1975 so that “global warming stopped 17 years ago. Think about it. Take that first figure a just select the last 10 years. The trend will also not be significantly different to zero – are we then going to claim something happened in 2002 to “stop” global warming?

No, of course not. The only reason 17 years is mentioned is that one can’t go back further than that without the trend being significantly different from zero. It’s a cherry-picked date – cherry picked to produce a non-significant trend.

Have IPCC models been disproved

Another common claim is that the very recent plateau, or decrease in the rate of global warming proves the scientific climate models are wrong.  More specifically I have often heard the claim that since this plateau has occurred while atmospheric CO2 levels continue to increase this proves that CO2 is not driving global warming. Even the claim that the plateau has somehow shown the scientific understanding of the fundamental properties of greenhouse gases is wrong.

The naivety of the last claim is to think that climate scientists  consider CO2 to be the only factor influencing the climate – they just don’t. Consequently one should not expect to see a simple correlation between global temperature and atmospheric CO2. Any attempt to understand or model climate change must include many more inputs than CO2.

As for models in general here is a couple of factors:

  1. All models are inaccurate. That’s just the nature of the attempt to understand complex systems – we can’t expect to get things perfect. And when anomalies occur this may actually help us improve the models by incorporating other factors or more realistic physical parameters. Despite this models have important uses as long as we understand their limitations.
  2. Models require inputs – inputs which may change, often unpredictably, over time. Therefore it is silly to expect model projections to always be correct or accurate further down the track.

For example, there could be weather conditions increasing heat inputs into the deep ocean which could not have been incorporated several years ago. Or there could have been an increase of particulates from increased coal use which had not been predicted. Political changes can produce economic changes which influence inputs. These are some of the ideas that have been suggested to help explain the current plateau or reduced rate of global temperature increase.

So the real test of the model is not to use inputs based on predictions made several years before, but to update inputs so that the model more correctly represents current situations.

But, more basically, it’s important to recognise that the global climate is complex. Simple mechanisms are not going to explain the details in the global temperature record. So be careful of people who advance simple explanations to discredit the science.

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Climate change is not simple Ken Perrott Mar 03

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I have said this before – but it bears repeating Climate change is complex. And I feel the need to repeat it now because of a current myth being pushed very strongly by climate change deniers/contrarians/sceptics. The claim that “there has been no global warming for 16 years.”

If you doubt climate change is complex have a look at this global temperature record from NASA’s Goddard Institute for Space Studies.

Fig.A2

Line plot of global mean land-ocean temperature index, 1880 to present, with the base period 1951-1980. The dotted black line is the annual mean and the solid red line is the five-year mean. The green bars show uncertainty estimates. [This is an update of Fig. 1A in Hansen et al. (2006).]

Isn’t cherry picky wonderful?

There’s a lot of noise in that graph but it does sort of support the conclusion that global temperatures have increased in the last 100 years. Mind you, if you want to create a contrary impression you can easily take a short time period – say around 1950, 1960 – 1980, 1985 – 1995 – or even the last 16 years. Cherry picking is a great thing – if your aim is to support a predetermined conclusion, and avoid (or even hide) evidence to the contrary.

So we get this sort of thing being promoted by climate change deniers (thanks to Andy for this one). Didn’t someone say a little knowledge is a dangerous thing? And isn’t cherry picking a great way of restricting knowledge?

Graph-billboard

So, just to repeat myself – here’s an extract from my post Climate change is complex. It indicates some of the scientific knowledge that climate change deniers/contrarians/sceptics ignore when they cherry pick to make this silly claims.

Natural influences just can’t explain global temperature

The figure below shows the results of simulations of global temperature from 1900 to 2005. Figure a included all the natural and anthropogenic influences.  The black line is the actual measured global temperature anomaly (obtained by subtracting the average temperature for 1901 to 1950).  The individual simulations are shown as thin yellow curves. The red line is the multi-model ensemble mean (see Figure 9.5 – AR4 WGI Chapter 9: Understanding and Attributing Climate Change).

Figure b is a similar plot using simulations which consider only the natural influences on climate. The individual simulations are shown as thin blue curves. The thick blue line is the multi-model ensemble mean.

So, climate scientist have considered both natural and anthropogenic influences. And they are unable to reproduce the global temperature changes since 1970 unless anthropogenic influences are included.

That is why the IPCC has concluded that there is a high probability (>90%) that human influences are contributing to the current observed global temperature increase.

Notice also that the experts talk about probabilities. It’s a complex field and things are rarely cut and dried. We are more certain about some influences than others. And the IPCC doesn’t hide this fact – far from it. It doesn’t make sweeping claims in the way that some of their opponents do.

Knowing what we don’t know

We can see this in another figure from the report (Figure 2.20 – AR4 WGI Chapter 2: Changes in Atmospheric Constituents and in Radiative Forcing). It shows the estimated influences of several human caused effect and solar radiation since 1750. Notice the error bars. They are much bigger in some cases than others. Notice the assessment of scientific understanding for these influences. We have a high understanding for some of them and a low understanding for others.

So, climate scientists aren’t hiding anything. They are not ignoring natural effects. They are up-front about probabilities. They acknowledge that we need more information is some areas. They are behaving like professionals.

Considering there are areas where scientific understanding is low there is clearly room for debate, discussion and more research. But deniers and contrarians who take an extreme reductionist stance, misrepresent the IPCC reports and attack honest scientists doing the research are not in a position to contribute to this.

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Deconstructing climate change, and its deniers Ken Perrott Jan 15

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I presented these IPCC graphs some time back in Climate change is complex. They underline the fact that climate changes are caused by a number of factors (natural and human-caused) so any successful modelling of global temperature changes needs to take all the factors into account. The graphs show how omission of human caused factors produces model results inconsistent with measured values.

Figure a included all the natural and anthropogenic influences. The black line is the actual measured global temperature anomaly (obtained by subtracting the average temperature for 1901 to 1950). The individual simulations are shown as thin yellow curves. The red line is the multi-model ensemble mean (see Figure 9.5 – AR4 WGI Chapter 9: Understanding and Attributing Climate Change).
Figure b is a similar plot using simulations which consider only the natural influences on climate. The individual simulations are shown as thin blue curves. The thick blue line is the multi-model ensemble mean.

These figures show how simple plots of global temperate over time cannot identify causes – a more complex investigation involving modelling was required. This enabled contributions from non-natural and natural causes to be identified.


Now the blog Skeptical science has produced a video showing a similar deconstruction of the factors causing global temperature change. The purpose was to show the falseness of recent claims by climate change deniers/contrarians/sceptics of no human contribution to climate change because they have observed no warming in the last 16 years.

Short term temperature changes are the results of several natural and human caused factors. But only the human caused emissions of CO2 is causing a steady effect which becomes clear when long-term changes are considered (even if not clear in the short term).

http://youtu.be/u_0JZRIHFtk
(Thanks to Still warming after all these years (again) at Hot Topic).


Finally, here is another graph which has the climate change deniers/contrarians/sceptics buzzing. It’s from the UK Met Office (see Decadal forecast). The buzz arises from the Met Offices revisions of “near-term’ climate prediction because of improvements in the modelling.

fcst_global_t4

Observed (black, from Hadley Centre, GISS and NCDC) and predicted global average annual surface temperature difference relative to 1971-2000. Previous predictions starting from June 1960, 1965, …, 2005 are shown as white curves, with red shading representing their probable range, such that the observations are expected to lie within the shading 90% of the time. The most recent forecast (thick blue curve with thin blue curves showing range) starts from November 2012. All data are rolling annual mean values. The gap between the black and blue curves arises because the last observed value represents the period November 2011 to October 2012 whereas the first forecast period is November 2012 to October 2013.

Actually, the denier/contrairan/sceptic buzz arises because the revised (improved) predictions are a “little lower” than the previous one. This has caused them (the deniers/contrarians/etc) to claim this proves global warming has stopped, and that human-caused climate change has consequently been proven wrong!
Of course this is wishful, and motivated, thinking on their part. The predictions produced by the Met Office rely on simulations using the best and most up to date models. The models incorporate all the factors known to influence global temperatures – including that caused by human burning of fossil fuels!

It’s a strange old world. The deniers/contrarians/sceptics who wish to deny human contributions to climate change have been sucked in by the Met Office sort term predictions of global temperatures. These deniers/contrarians/etc., are now touting models in support of their claims which in fact are based on the effects of such human contributions.

They are relying on the very thing they wish to deny!

See also:
Updates to our decadal forecast
Has global warming ground to a halt?

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Deconstructing climate change, and its deniers Ken Perrott Jan 15

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I presented these IPCC graphs some time back in Climate change is complex. They underline the fact that climate changes are caused by a number of factors (natural and human-caused) so any successful modelling of global temperature changes needs to take all the factors into account. The graphs show how omission of human caused factors produces model results inconsistent with measured values.

Figure a included all the natural and anthropogenic influences. The black line is the actual measured global temperature anomaly (obtained by subtracting the average temperature for 1901 to 1950). The individual simulations are shown as thin yellow curves. The red line is the multi-model ensemble mean (see Figure 9.5 – AR4 WGI Chapter 9: Understanding and Attributing Climate Change).
Figure b is a similar plot using simulations which consider only the natural influences on climate. The individual simulations are shown as thin blue curves. The thick blue line is the multi-model ensemble mean.

These figures show how simple plots of global temperate over time cannot identify causes – a more complex investigation involving modelling was required. This enabled contributions from non-natural and natural causes to be identified.


Now the blog Skeptical science has produced a video showing a similar deconstruction of the factors causing global temperature change. The purpose was to show the falseness of recent claims by climate change deniers/contrarians/sceptics of no human contribution to climate change because they have observed no warming in the last 16 years.

Short term temperature changes are the results of several natural and human caused factors. But only the human caused emissions of CO2 is causing a steady effect which becomes clear when long-term changes are considered (even if not clear in the short term).

http://youtu.be/u_0JZRIHFtk


(Thanks to Still warming after all these years (again) at Hot Topic).


Finally, here is another graph which has the climate change deniers/contrarians/sceptics buzzing. It’s from the UK Met Office (see Decadal forecast). The buzz arises from the Met Offices revisions of “near-term’ climate prediction because of improvements in the modelling.

fcst_global_t4

Observed (black, from Hadley Centre, GISS and NCDC) and predicted global average annual surface temperature difference relative to 1971-2000. Previous predictions starting from June 1960, 1965, …, 2005 are shown as white curves, with red shading representing their probable range, such that the observations are expected to lie within the shading 90% of the time. The most recent forecast (thick blue curve with thin blue curves showing range) starts from November 2012. All data are rolling annual mean values. The gap between the black and blue curves arises because the last observed value represents the period November 2011 to October 2012 whereas the first forecast period is November 2012 to October 2013.

Actually, the denier/contrairan/sceptic buzz arises because the revised (improved) predictions are a “little lower” than the previous one. This has caused them (the deniers/contrarians/etc) to claim this proves global warming has stopped, and that human-caused climate change has consequently been proven wrong!
Of course this is wishful, and motivated, thinking on their part. The predictions produced by the Met Office rely on simulations using the best and most up to date models. The models incorporate all the factors known to influence global temperatures – including that caused by human burning of fossil fuels!

It’s a strange old world. The deniers/contrarians/sceptics who wish to deny human contributions to climate change have been sucked in by the Met Office sort term predictions of global temperatures. These deniers/contrarians/etc., are now touting models in support of their claims which in fact are based on the effects of such human contributions.

They are relying on the very thing they wish to deny!

See also:
Updates to our decadal forecast
Has global warming ground to a halt?

Similar articles

Agreement polar ice sheets are melting Ken Perrott Dec 02

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Many climate scientists felt the conclusions on effects of global warming in the 2007 IPCC review were too conservative. One reason was the estimation of likely melting of ice sheets and its effects.

Problem was that there was insufficient knowledge to draw definite conclusions. And the measurements of changes in ice sheets just wasn’t accurate enough.

That’s now changed and a large number of experts agree global warming has caused loss of ice from these ice sheets. And this has contributed to measured increases in sea level.

Richard A. Kerr reports in Science (see Experts Agree Global Warming Is Melting the World Rapidly):

“Forty-seven glaciologists have arrived at a community consensus over all the data on what the past century’s warming has done to the great ice sheets: a current annual loss of 344 billion tons of glacial ice, accounting for 20% of current sea level rise. Greenland’s share—about 263 billion tons—is roughly what most researchers expected, but Antarctica’s represents the first agreement on a rate that had ranged from a far larger loss to an actual gain. The new analysis, published on page 1183 of this week’s issue of Science, also makes it clear that losses from Greenland and West Antarctica have been accelerating, showing that some ice sheets are disconcertingly sensitive to warming.”

He’s referring to the major paper by Andrew Shepperd and others, A Reconciled Estimate of Ice-Sheet Mass Balance.

Over recent years climate change deniers/contrarians/sceptics have cherry picked data to counter any suggestion that the earth’s large ice sheets are melting. They have pointed to increased amounts of ice in Eastern Antarctica to balance reports of massive losses of ice in the Arctic. (Have a look at this animation to see how such data can be cherry picked). Similarly they have tried to hide concern of the loss of land ice by stressing reports of local increases in sea ice.

But the paper by Shepperd et al. combined data from satellite altimetry, interferometry, and gravimetry measurements. This provides more reliable estimates of changes in the ice sheets, and gives some detail of these changes. This figure from the paper gives an idea of the detail of their findings. It shows that all the major regions of the polar ice sheets except one (East Antarctica) have lost mass since 1992. The authors also estimate that mass loss from the polar ice sheets has contributed roughly 20 percent of the total global sea level rise during that period (at a rate of 0.59 ± 0.20 millimeter year−1 ).

Figure S1 from Shepperd et al.: Cumulative ice mass change of West Antarctica ((WAIS) East Antarctica (EAIS), Greenland (GrIS), and the Antarctic Peninsula (APIS).

And to underline the fact that denier claims of amounts of ice increasing in Antarctica are false, NASA recently displayed this figure showing data from Antarctica from their satellite measurements

Monthly changes in Antarctic ice mass, in gigatones, as measured by NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites from 2003 to 2011. Image credit: NASA-JPL/Caltech; NASA GSFC; CU-Boulder; Technical University of Munich; Technical University of Denmark; Delft University of Technology, Aerospace Engineering, Netherlands; Durham University, UK; Leeds University, UK

Could those climate change deniers/contrarians/sceptics please stop hiding behind claims that gains by Antarctic ice sheets balance losses from ice sheets in Greenland and the Arctic.

They don’t.

See also:
Science: Major Regions of Polar Ice Have Been Shrinking Since 1992
Polar Ice Sheets Losing Mass, Several Methods Show
New Study Shows Global Warming Is Rapidly Melting Ice at Both Poles
Human-Caused Climate Change Signal Emerges from the Noise
Study: Polar ice sheets in Antarctica, Greenland melting 3 times faster than in ’90s
Ice Sheet Loss at Both Poles Increasing, Study Finds
Projections of sea level rise are vast underestimates
“Hard” “Authoritative” Evidence Of Climate Change Begins To Overwhelm Even Fox

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Who are these “credible experts”? Ken Perrott Oct 29

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There is a nice article over at A Few Things Ill Considered about climate change denial. And I thank Grant, from the Code for Life blog, for bringing it to my attention.

The image I have of local climate change denial activists

Climate Trolls – An Illustrated Bestiary produces an illustrated list of the different types of personality among climate change denial activists, and the websites or blogs they tend to congregate around.

There is ,The Galileo Gambiter, The Auditor, The Sanctity of Science concern troll, The Faux Skeptic, The Uncertainty Monster monster, The Avenger, The Gish Galloper, Hockey Goon, The Conspiracy Theorist, The Right Wing Ideologue and Breakthrough Boys. Each with photos illustrating how they see themselves, and how the public see them.

It’s quite an entertaining read.

This one - The Not the IPCCer – struck close to home. It seems to describe the group that gathers around the NZ denier blog sites Climate Conversation Group. And the picture of “How the world sees them” coincides with my image of people who find it impossible to get a life and instead spend all their time attached top their computer passing on links to anything they can interpret to fit their world view.

Here’s how coby at A Few Things Ill Considered describes this subspecies:

The Not the IPCCer – whatever was said on whatever topic by any of the IPCC reports, the opposite must be true.  Indeed there has never been a single correct statement made or paper published by any member of mainstream climate science. This conviction extends to even the most non-controversial and well supported contentions found in the literature and is accompanied by complete ignorance of what is found in the literature.

How they see themselves

How the world sees them

Favorite blog:     Watts Up With That
Special attack:    Peer review really means “Pal review” and Michael Mann and Phil Jones control all the major journals and all the world’s science institutions.
Favorite Topic:   Whatever the latest typo found in the latest IPCC report is.
Best counter:      Light.  The copious self-contradictions permeating their minds thrives only in darkness.

These local activists have been very vocal (at their own watering hole, anyway) since their defeat in the recent high court action they took against NIWA scientists. They have resorted to everything to justify their stance, avoid paying the NIWA  costs awarded by the courts and claim the real climate expertise rests with them, rather than New Zealand’s climate scientists.

Currently one of the most central figures in this little band is Manfred Otto Dedekind (See Shy climate denier in “science team” reveals himself for details). Manfred (who goes by the alias Bob D) on the internet was the “anonymous science team” behind the infamous attack on NZ scientists “Are we getting warmer yet?” The document which claimed that the evidence showed that no adjustments of NZ temperature data was necessary to accommodate site changes and that NIWA used such adjustments to invent an increase in temperatures.

He then did an about turn (without acknowledging that huge error) by agreeing that adjustments are necessary, doing his own manipulations of the data and telling NIWA his adjustments were the only correct ones. That NIWA had purposely got it all wrong. He and his mates used his “analysis” as their evidence in the High Court case (see High Court ruled on integrity – not science). Quite rightly, the court refused to accept that he was the climate expert he claimed to be (he has no publications at all in the area, 4 [very old] scientific publications in total – only two of which he is the senior author. I can see why his group initially wished to keep him anonymous).

But this hasn’t stopped these characters from getting behind Manfred and promoting him as an Über climate expert. One of their sister denier blogs Tallbloke’s Talkshop describes Manfred as an “expert” and a “statistician!”  (see How NIWA added lots of warming in New Zealand – and got away with it – so far). And Watts Up With That, a prominent denial blog, is describing him as a credible expert!

These guys live in a world of their own. No wonder they find trouble in getting a life.

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A concise summary of climate change – science and politics Ken Perrott Oct 16

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Here’s a relatively short (26 min) video of a lecture by Michael Mann. I think it gives a very concise and accurate picture of the current science of climate change and the political attacks on climate scientists (Mann calls this the scientization of politics).

via The Hockey Stick and the Climate Wars – Michael Mann Speaks at SOS 2012 on Vimeo.

From the video description:

Michael E. Mann- Director of the Earth System Science Center gives a very eye-opening presentation at the 2012 Sustainable Operations Summit. Mann’s presentation highlighted themes from his most recent book: The Hockey Stick and the Climate Wars: Dispatches from the Front Lines. In his talk, Mann discussed the “Hockey Stick,” a graph he created with his colleagues to depict changes in Earth’s temperature dating back to 1000 AD. The graph was featured in the Summary for Policy Makers portion of the 2001 report of the Intergovernmental Panel on Climate Change (IPCC) and became an icon in the debate over human-caused climate change. Mann told the story behind the Hockey Stick, using it as a vehicle for exploring broader issues regarding the role of skepticism in science and the relationship between science and politics.

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Another anti-science attack on Mann fails – but the lies continue Ken Perrott Sep 19

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Michael Mann

Once again legal action by climate change deniers/contrarian/cranks has failed. In the US attempts by the  American Tradition Institute, a climate change denial think tank, to obtain personal emails and documents from  the University of Virginia. These documents belong to well known climate scientist Michael Mann and the court action was part of a fishing expedition by climate change deniers to repeat the “climategate” scandal. To obtain emails from which cherry-picked material could be used in the ongoing campaign to discredit climate scientists. See University of Virginia prevails against climate science attack groupfor further information on this case.

But Michael Mann is certainly the scientist that the climate change deniers/contrarians/cranks love to hate. Just recently I was assured by a local climate change deniers/contrarian/crank that Michael Mann had been thoroughly discredited. That his so-called Hockey Stick image, which had appeared in the 2nd to last IPCC review (AR3) had been dropped from the most recent IPPC review (AR4). This local denier/contrarian/crank asserted, for example:

“You’re going to have to come up with someone other than Mann, to be taken seriously.”

“I don’t need to prove Mann wrong, plenty of far better people have already done that.”

“Mann has been so often deprecated he is without authority.”

“The Mann saga is over, even the IPCC has dropped Mann’s hockey stick graph.”

This attempt to discredit Mann and his work is a lie – but its not a new lie. It’s one I had dealt with almost three years ago in my post Climate change deniers’ tawdry manipulation of “hockey sticks”. I am repeating that post here, with slight amendments. Hopefully this will at least lead to some climate change sceptic who may have accepted that lie getting some of the real facts.

The “infamous, discredited” hockey stick

The charge is:

“Mann’s hockey stick has been thoroughly discredited and the IPCC has dropped it from its reports.”

But it’s simple enough to check the IPCC reports – they are on-line for all to see. If you do check you will find this figure below in the 2007 reports. The original data from Mann (MBH 1999) is included with, of course, more recent data. Here is the reference for anyone doubting my claim - Figure 6.10, page 467,  Chapter 6: Palaeoclimate,The Fourth Assessment Report (AR4), WG I The Physical Science Basis.

And far from this work being “thoroughly discredited” or abandoned, it has been expanded with more, recent, data. The graph below is from Mann’s 2008 paper (Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia).

National research Council report vindicates Mann

In this paper Mann was responding to suggestions made by the National Research Council in its report  Surface Temperature Reconstructions for the Last 2,000 Years. This thorough and rigorous investigation formed part of US House of Representatives Committee hearings on Mann’s “hockey stick” figure arising from criticisms made by climate change sceptics. It is very authoritative.

Anyone who has ever had their work reviewed knows that a reviewer worth their salt will always find your weaknesses and suggest amendments, even though they endorse your work. And climate changer deniers/contrarians/cranks have hunted out the criticisms, taken them out of context and are usually well versed in those cherry-picked quotes. They must be repeated ad nauseum in those unreliable books deniers rely on as sources. But the fact is the National Research Council report basically supported Mann’s findings:

“The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes both additional large-scale surface temperature reconstructions and pronounced changes in a variety of local proxy indicators, such as melting on ice caps and the retreat of glaciers around the world, which in many cases appear to be unprecedented during at least the last 2,000 years.”

In fact the NRC produced their own “hockey stick,” using more than just Mann’s data, in the report (see figure below):

Lord Monckton’s lies about the “hockey Stick”

These false assertions on the “hockey stick” graph are, unfortunately, very common. It’s one bit of mudslinging that has found purchase with most deniers repeating the lie. Even some sceptics believe the story.

Lord Mockton has been a prolific propagator of this lie. He even appears in the infamous “climategate” emails saying of the “hockey stick”: “the US National Academy of Sciences has described as having “a validation skill not significantly different from zero”. In plain English, this means the graph was rubbish.”

Problem is – search through the NRC report and you just won’t find those words (“a validation skill not significantly different from zero”). Nevertheless this allegation has been repeated innumerable numbers of times in conservative newspapers and websites. Some of these also claim that the IPCC had abandoned the data (see for example the policy Brief from the Commonwealth foundation – Climate & Penn State – demanding a McCarthyist-style investigation of Mann). But even Mockton acknowledges that the UN continues to use the defective graph.”

I guess it just makes a good story so these conservative sources tack it on. But  where is the integrity in that?

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See also:
Journalist thinks world climate-science publications are controlled by cabal
Analysis of stolen CRU emails by NZ blogger shows tawdry manipulation of facts – Poneke’s credibility now in tatters — Hot Topic

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