"all global proxy reconstructions agree it is warmer now, and the temperature is rising faster now, than at any time in the last one or even two thousand years"

After the NAS report, don't you think this is a bit misleading/over-reaching?

It is missing the qualifications and quantified uncertainties that you will find in the details of the particular studies, but I don't think it is inappropriate, it does seem to match the quote from NOAA that they were comfortable with.  Perhpaps it would be better to say "it is likely warmer now", more correct and not any less clear.

While the NAS report did discuss some general aspects of all proxy studies (like they get more uncertain the further back in time they go) don't forget it was primarily about the "Hockey Stick" (aka MBH89) which is a single 8 year old work.  Time and science have moved on even if Michaels and Lindzen haven't!

Invent a clever saying, and your name will live forever! -- Anonymous

John Tukey was one of the world's greatest statisticians, and he had good observations:

"Far better an approximate answer to the right question, which is often vague, than an exact answer to the wrong question, which can always be made more precise."

"The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data."

Whether or not we are now warmer than the MWP is the wrong question, and in fact, as interesting as it might be, arguing it gives a perfect opportunity for anyone who wants to create clouds of confusion to do so.

The argument "it's warmer than the MWP, and therefore we should do something about AGW" invites the response "but we really don't know", and then lots of confusing side-tracks.

The stronger argument to me is: "Whether we are warmer or not already, we're going up fast, and the physics says we're going to keep going up, we have 10X more people on the planet, and 50% of the world's population lives within 120 miles of the ocean, and anything we can do to slow down the inevitable temperature rise will give more time for ecosystems adaptation, will likely cost less, and maybe will save some wars (over water, if nothing else)."

Suppose someone could magically duplicate our current temperature sensors 10,000 years back, and have a current-technology record from then.  Climatologists would be ecstatic, and models might improve, but otherwise, what would you do differently if it turned out the MWP were global, and a little warmer than now? or global and a little cooler? or not global?  

-John Mashey

Good points John.  I have written before that knowledge of the past can be very informative, but it is not explanatory for today, nor predictive of tomorrow.

"What if this weren't a hypothetical question?" -- unknown

Comment to John Mashey.

For a comprehensive summary of evidence for a global Medieval Warm Period check:

Soon, W. and Baliunas, S., "Proxy climate and environmental changes of the past 1000 years", Climate Research, Vol 23: 89-110 (2003)

Regards,

Max Anacker

Hi Coby,

I've been following the blogs on this subject and here are my thoughts:

Is the Medieval Warming Period Irrelevant?

A commonly heard argument among IPCC supporters is that it is irrelevant to the current reality of global warming whether or not the Medieval Warm Period was global, with temperatures higher than today (a fairly-well documented historical fact), because the climate models show in any case that our current higher CO2 concentrations will lead to DISASTROUS warming (a computer-generated virtual reality).

If it is REALLY irrelevant whether or not the MWP was global and that temperatures then were warmer than today, why does the IPCC have to rely on a discredited "hockey stick" curve to make the alarmist claim that "the warmth of the last half century is unusual in at least the previous 1300 years"?

Wegman is quoted as saying "In a real sense the paleoclimate results of MBH98/99 (the "hockey stick") are essentially irrelevant to the consensus on climate change", but as he summed it up to the energy and commerce committee in testimony: "Overall, our committee believes that Mann's assessments that the decade of the 1990s was the hottest decade of the millennium and that 1998 was the hottest year in the millennium cannot be supported by his analysis," and "I am baffled by the claim that the incorrect method doesn't matter because the answer is correct anyway. Method Wrong + Answer Correct = Bad Science."

Why not just delete this bit of BAD SCIENCE from the report if it is so IRRELEVANT?

Any good answers?

I think we know the answer. The MWP is an embarrassment for "disaster scenario" claims, for example that polar bears, etc. are facing extinction due to the climate changes today, despite the fact that they have survived for a very long time, including some longer periods of even warmer climates.

The "hockey stick" is used to substantiate the IPCC disaster claims, even though it has been shown to be a fraud.

Let's face it: slight warming over the past century (and possibly the next one), for whatever reasons, is real, as the record shows; impending DISASTER due to anthropogenic CO2 emissions is an imagined, computer-generated scare scenario, that does not pass the "sanity check" of common sense or the historical record, regardless of what the models, the media and the politicians may say.

I challenge anyone to prove that this is wrong.

Max Anacker

Reply to greyfalcon:

Thanks for your comment.

I fail to see in the references you cited that Soon and Baliunas were "discredited" (as Mann was earlier for his "hockey stick"), just that some editors disagreed and a couple resigned.

The "more" correct hockey stick, which you cite may be "more" correct than Mann's first one, but maybe "less" correct than some other curve showing a warmer MWP.

So far you have not been able to convince me that we are living in an unprecedented warm period today.

Regards,

Max

Reply to greyfalcon.

Wow! Looks like I hit your hot button.  Don't get excited.  And don't try to discredit IPCC critics by tying them to Phillip Morris or Exxon, or just claiming they are "consistently wrong about climate science".

I am just questioning the validity of the claims in the IPCC report regarding  "unprecedented 20th Century warmth".

Arguments used to support IPCC this claim include:

·    There was no Medieval Warm Period, also no Little Ice Age (Mann "hockey stick").
·    Greenland really wasn't "green" in 1000AD; it was just a "PR ploy by Eric the Red, to make the colony sound attractive".
·    There was a MWP and a LIA, but these were only local to some parts of Europe.
·    There was a MWP and a LIA, but temperatures today are even higher than in the MWP.

The first two of these arguments do not need to be refuted.  They have already been shown to be false.

The next two should be taken more seriously.

The "only in parts of Europe" hypothesis has been shown to be incorrect by many studies that have been reported, covering not only Europe (Spain, Italy, Germany, Scandinavia, England, etc.), but also:
·    Russia
·    Greenland
·    North America
·    Sargasso Sea
·    China
·    India
·    New Zealand
·    South America

These are all available to the public.

The "not as warm as today" hypothesis is often backed up by statements such as (NOAA) "we don't have enough good data" for the MWP and therefore the current warmth is very likely unprecedented. The "not as warm as today" hypothesis has also been shown to be incorrect by many of the studies referred to above, which point to temperatures between 1 and 4°C warmer than today. These also show that today's temperatures, while clearly rising, are still closer to those in the LIA than they are to those during the MWP.

Not too many people deny that temperatures are rising today.

Not too many people deny that CO2 levels are rising today.

Why not just leave it at that?  Why do "scare scenarios" have to be built up using false or questionable data?

There is no doubt that we should conserve energy where possible and reduce our dependency on imported fossil fuels plus end pollution, deforestation, and other environmental carelessness; but we should not use lies or distort science to scare the people.

And that is what the IPCC is doing.

So relax, we are just trying to find out what the real truth is.

Regards,

Max

In one location in China.

Local temperatures and Global temperatures are not the same thing.

The "not as warm as today" hypothesis has also been shown to be incorrect by many of the studies referred to above, which point to temperatures between 1 and 4°C warmer than today.

Please do name one.

With one detail, that it's not just a LOCAL temperature reading, and rather a global temperature reconstruction.

Singer
Soon and Baluinas
McIntyre and McKitrick

Those are the only ones I know of, and those have all shown to be invalid.

Ho hum. You are not convincing me, because you do not have facts, only theories.

Here are the facts:

Global temperatures are going up very slightly  (for some time now).

Atmospheric carbon dioxide is going up (at least for the past 50 years, since we have measurements).

That's it, folks.

Global temperatures have been higher than today in the past (with lower carbon dioxide levels).

Disaster has not happened in the past.

Use your common sense, guys, and don't blindly believe the virtual reality of computer models that predict disaster.

Computers are great, but they cannot replace common sense, no matter how sophisticated they are.

We are not facing a disaster.

So you can relax.

Regards,

Max

Ho hum. You are not convincing me, because you do not have facts, only theories.

Here are the facts:

Global temperatures are going up very slightly  (for some time now).

Atmospheric carbon dioxide is going up (at least for the past 50 years, since we have measurements).

That's it, folks.

Global temperatures have been higher than today in the past (with lower carbon dioxide levels).

Disaster has not happened in the past.

Use your common sense, guys, and don't blindly believe the virtual reality of computer models that predict disaster.

Computers are great, but they cannot replace common sense, no matter how sophisticated they are.

We are not facing a disaster.

So you can relax.

Regards,

Max

Reply to greyfalcon

Hey, I think jabailo has got it right.

CALCULATED "Global" temperatures are just a computer-generated composite of ACTUAL "local" temperatures.

If I am sitting in Hong Kong, I feel the "local" temperature there.  If I am sitting in Antarctica, I feel another "local" temperature.

The "global" temperature (day or night, summer or winter) does not mean very much to anyone, does it?

The fact that many LOCAL temperatures were shown to be higher during the MWP than today (as jabailo points out for China) is very relevant to the question of whether GLOBAL temperatures were higher then than now.  Don't you agree?

Regards,

Max

Global temperatures have been higher than today in the past (with lower carbon dioxide levels).

Disaster has not happened in the past.

Except that you can't prove anything about global temperatures.

All you have is some local temperatures.

And you won't even cite any of your sources.

Reply to greyfalcon.

"Except that you can't prove anything about global temperatures."

Nor can you.

So I guess we are even.

Regards,

Max

Thanks for comment.

Let's see where you and I agree on things.

1. Energy conservation  

Believe we both agree it makes good economic and environmental sense to reduce energy waste at the personal level (low energy light bulbs, more efficient automobiles, better home insulation, installing solar panels to reduce power requirement, etc.).

At the industrial level most energy is used in manufacturing processes. Cutting manufacturing costs through more efficient use of energy also makes sense, and most companies have programs underway to do this.

Anything we can economically do to reduce our dependence on imported oil is good.  If it makes us feel better because it also reduces our "carbon footprint" (which I am personally not worried about, but you are), so much the better.

Do we agree so far?

2. New non-fossil based automotive fuels

The automotive industry has a lot of R+D work going on for developing and improving electric or hybrid cars, cars driven with hydrogen, etc.

This is all great, but these technologies still require a basic source of energy to produce the electrical power or hydrogen.  The only way to solve this is to install new power generation plants, and near-term the only economically acceptable non-fossil fuel solution is nuclear generation.

I can live with that.  Unfortunately many people in Europe and North America have been frightened by the anti-nuclear "scare" stories generated by environmental lobby groups (much like the CO2 "scare" stories that are now being promulgated by IPCC and spread via the media and politicians).

So it looks like we first have to undo the damage from these "scare" stories, before we could convince people to go nuclear. It's a real toughie for outfits like Greenpeace, that now have to choose between a nuclear and a carbon footprint.

Longer-term new economically viable non-fossil fuel generation methods could be developed. Fusion reactors (converting deuterium into helium) are still a long way off.  

I don't give solar or wind power much chance to ever become economically viable or feasible on a scale large enough to make a major impact, unless basically new technologies can be developed.  Do you?

Following Brazil's apparent success in converting to sugar cane derived ethanol (from corn, biomass or whatever) could be another way to get away from imported oil.  As I understand it, the economics are still dicey for corn-based ethanol, but maybe these can be improved with new technologies or genetically modified high sugar yield corn. I could sure live with this, as well, but we might have trouble with the green groups who are opposed in pricipal to genetically modified crops and with people who have been influenced by "scare" stories spread by these groups.

Bio-mass as an economically viable source of energy at a large scale is still a thing of the future, but I am all for developing new technologies that make economic and environmental sense.

Are we still on the same track?

3. Carbon capture and injection

One proposed solution for CO2 emissions is "carbon capture" of the stack gases from large power stations and injection back into permeable underground layers of the earth.  This does nothing to conserve energy.  In fact the energy required to compress and inject the CO2 would be substantial so it is a solution that wastes energy rather than conserving it.

The long-term environmental unknowns of injecting massive quantities of CO2 into the earth seem to me to be a much greater risk than letting the CO2 go into the atmosphere, where it is already a minor natural component.

In addition, the technology for doing all this efficiently does not exist and, even if and when it is developed, it would do nothing for smaller energy users, such as automobiles.

So this is one "solution" that I would oppose. How about you?

4. Carbon taxes

IPCC promotes the "Kyoto solution" of establishing carbon taxes to "force" the price of fossil fuels upward.  This opens a can of worms, such as bureaucratic "carbon footprint offset schemes", trading mechanisms, etc. NONE OF WHICH do anything to either conserve energy or reduce CO2 emissions.

IPCC estimates that we currently emit 26 Gt of CO2 per year, which is equal to 7 Gt of carbon.  At a "carbon tax" of  $30 per ton this represents an additional tax on mankind of $210 billion per year, a large part of which will go to paying the bureaucrats that will have to enforce and administer the schemes.

Sure, the money-shufflers will all make a buck on these schemes (International Herald Tribune reported on May 3 that it is a $30 billion business in Europe today, with hedge funds and other new entrants tripling the European trading volumes).

So I see this as an expensive, bureaucratic "non-solution" to what I consider to be a "non-problem".

I know you do not agree the CO2 emissions are a "non-problem".

But can you agree with me that this is a "non-solution", because it does nothing to solve CO2 emissions?

5. Using "scare" tactics to force people to think and act differently

This is where I have the greatest problem with the IPCC.  They are spreading disaster stories under the guise of "science".  The media love "scare" stories, as do the politicians and the environmental activist groups, so everyone hops on the wagon.

Then there are the guys that "scared" us out of nuclear power generation, and now we have to undo the damage in order to get non-fossil fuel power generation plants built.

The same "scare" tactics that got DDT outlawed worldwide, causing millions of new malaria cases and deaths, until the WHO finally lifted its ban on DDT recently.

Throughout the years, politicians have used "scare" tactics to increase their own power and justify all sorts of bad things. This is no different today, but it is hidden under the mantle of "saving the planet from man".

Teachers get our children all anxious by spreading these "scare" stories in school. Ask a 10-year old what his/her greatest fear is, and you are likely to get the answer "floods and storms caused by global warming". It is irresponsible for teachers to scare their pupils, no matter what imagined "good cause" is behind it.

The "scare" stories do not achieve any positive environmental result.

Can you agree with me that spreading environmental "scare" stories is not a solution to the problem?

Let's see on how many of the above we agree.

Then we can concentrate our discussion or debate on those where we disagree.

Regards,

Max

Your disaster pics were apparently intended to link disastrous weather events with anthropogenic climate change.

Back in 1900 the USA's deadliest hurricane ever hit Galveston, killing over 8,000 people.  There were not many pictures sent around and no TV or even radio broadcasts.  

Nine of the ten deadliest hurricanes in the USA occurred before 1960, with Katrina (#3 in deaths) the only one since then.

Of the 25 deadliest US tornados, none occurred after 1955. Of the 30 deadliest US tornados, only 2 occurred after 1980.

I am certainly not a "climate denier".

I just find it hard to accept that these storms were caused by anthropogenic CO2 emissions.

Sounds like you may be a "MWP denier", though, as are the writers of the "several thousand peer-reviewed journals" you mention.

"Do any of you deniers have anything but pseudo-science and obfuscation? Anything with a link to a scientific paper? Not likely."

Tsk, tsk.  Sounds like you are losing your temper and starting to call names.  For shame.

For the MWP check out: Soon, W. and Baliunas, S., "Proxy climate and environmental changes of the past 1000 years", Climate Research, Vol 23: 89-110 (2003)

For the hurricane and tornado records, check out the NOAA websites.  If you want these references, I can provide them.

In the meantime, cool off.

Max

I'm surprised at you, denier guy.  You should be more sophisticated than to make a naked assertion and then expect someone here to pick it up as their own:

"Since every year is the 'hottest on record' we should have seen some Cat sixes, maybe even sevens?"

Do you have a proved connection between 'hottest on record' and 'Cat sixes, maybe even sevens?'

I don't think Time actually makes a very strong claim:

So is global warming making the problem worse? Superficially, the numbers say yes--or at least they seem to if you live in the U.S. From 1995 to 1999, a record 33 hurricanes struck the Atlantic basin, and that doesn't include 1992's horrific Hurricane Andrew, which clawed its way across south Florida in 1992, causing $27 billion dollars worth of damage. More-frequent hurricanes are part of most global warming models, and as mean temperatures rise worldwide, it's hard not to make a connection between the two. But hurricane-scale storms occur all over the world, and in some places--including the North Indian ocean and the region near Australia--the number has actually fallen. Even in the U.S., the period from 1991 to 1994 was a time of record hurricane quietude, with the dramatic exception of Andrew.</blockquote.<p> You're worried because they say "superficially, the numbers say yes?"

(The do go on to say that "more-frequent hurricanes are part of most global warming models" but that doesn't strike me as a strong claim either.

They certainly did not say that global warming impact would be strong enough to override every other aspect of the system (inc. random year to year variation).

you can see where i messed up that close quote.  that's what i get for posting after a mountain bike ride.  the brain's a bit hazy.

Reply to greyfalcon

"In particular, he says, the committee has a "high level of confidence" that the second half of the twentieth century was warmer than any other period in the past four centuries."

Duh! That was the LITTLE ICE AGE.

"But, he adds, claims for the earlier period covered by the study, from AD 900 to 1600, are less certain."

Duh, again!  That was the MEDIEVAL WARM PERIOD.

He also said, "Overall, our committee believes that Mann's assessments that the decade of the 1990s was the hottest decade of the millennium and that 1998 was the hottest year of the millennium cannot be supported by his analysis".

Is there anything unclear in this statement?

Regards,

Max

Reply to greyfalcon, part2

"Only thing that stuck with with the Wegman / McKitrick comments was that they didn't like that he used bristlecone pines."

We've covered Wegman's statement and committee report conclusion above. What "stuck" was that the conclusions of unprecedented warmth in the 1990s and the year 1998 were not supported.

M+M also showed that Mann's hockey stick reconstruction was flawed.  Other statements that "stuck":

"The MBH98 [hockey stick] methodology differed from what was stated in print and the differences resulted in lower early 15th century values."

They showed that "results adverse to their [Mann's] claims were not reported" and that in some cases there were "actual misrepresentations"

Then they criticized the "lack of due diligence involved in peer review" and criticized the IPCC for using the flawed hockey stick in climate policy reports.

Regards,

Max

Reply to greyfalcon

The conversation is starting to get repetitive.

Anyone can write a paper or article to defend a pet theory or put down a scientific report that disagrees with it.

Mann's hockey stick was DISCREDITED and with it the IPCC claim of unprecedented warmth in the 1990s.

Let's talk about something else.  OK?

Regards,

Max

You have kind of a weird determination of discredited.

90% certain for here through the LIA
And 60% certain for the MWP

That isn't bad odds in science stats.

Trick being stats always helps to have more and more reconstructions.
Which is what Moberg is all about.

Reply to greyfalcon

"Trick being stats always helps to have more and more reconstructions.
Which is what Moberg is all about."

Reconstructions, manipulations, justifications.

Whatever.

Bye,

Max

Reply to John Mashey

Thanks for interesting blog.

You are 100% right; it is sad, but true, that the alpine glaciers in Switzerland are retreating today.  They actually have been since the late 19th century.

I can see the Pizol out of my window.  This year there was not much winter snow (in contrast to last year), and we had a warm, sunny month of April (again, in contrast to last year when it snowed well into April). So there is not much snow to see now, just on the very top.

The region where I live has an interesting history, which is tied closely to earlier climate changes, such as the Medieval Warm Period and the Little Ice Age, both of which had major impact on the alpine glaciers of this region at the time.

As a descendant from emigrants from Switzerland, some of this history made be of interest to you.

In the late 10th century, a Germanic tribe settled in what is now the upper Valais (or Wallis, as it is called in German).  The climate then was milder than today, and the settlements high in the mountains flourished, resulting in a rapid growth of population.

According to the tradition then, only the eldest son inherited the entire land from his parents (in the case of feudal land it was actually the "right to farm" the land), so that soon there was a growing need for new land.

This trend resulted in an emigration of many families, already starting in the 11th century (much in the same way, I guess, that your ancestors emigrated from Switzerland due to economic pressures several hundred years later).

These German-speaking emigrants were called the "Valser" (after the Valais); they emigrated over the alpine passes into parts of Austria (Voralberg) and Graubünden in Switzerland, with some ending up in northern Italy.

This emigration continued over several hundred years, until the mid 14th century.

In the "Valser" regions of Graubünden, the new arrivals were welcomed by the feudal lords, who were looking for "able-bodied" mountain men to settle the lands and increase their wealth.  Most of the feudal lords were also German-speaking, even though most of the local peasants at the time spoke a Latin language, called Rumantsch (or Rhätoromanisch in German).  With this new immigration, the language border gradually shifted and German became the local language here, as the dwindling Rumantsch-speaking community was replaced by the new arrivals.

All during this period of milder climate, these settlements thrived and expanded. The alpine glaciers were then much smaller than today (it is estimated by around 15%).

With the 16th century came a change in climate.  The glaciers again started growing into what had previously been forestland.  The alpine passes, which the Valser had used in their emigration, again became closed in due to the glacial growth and the advancing glaciers destroyed alpine meadows and villages. This was the end of the expansion of the Valser into high alpine valleys

The settlers were forced to move further down into lower valleys.  Some found new pastures there where they could continue, but many others were forced to take work in newly developing occupations, such as mining, handicraft or transportation.

It was a hard time and many starved. The fast growth of the Valser population slowed down dramatically, due to the consequences of the harsher weather.

The glaciers advanced, off and on, for several centuries and reached their maximum size around 1850 (at an estimated 20% greater size than today).  Then they started to recede again, which they have been doing ever since.

Today you can't get "able-bodied" Valser to move back up into the newly greener valleys to herd cows and goats (they are all working in the Swiss "service" industries, such as tourism and banks).  

While there still are cowherds on the alpine pastures, most of the people in the old Valser high valleys are now making their living in the tourist industry serving winter (and summer) resorts.  Those that are relying on winter snowfall complain when it is mild (like this year) and make a better living when it snows a lot (like last year).  The farmers and cowherds complain in either case that they have a hard life (which they do).

A glacier retreats (or loses net mass) when there is more summer melting than there is winter snowing.  This is certainly the trend here in our region since around 1850.

So you see that glaciers receding, then growing, then receding again is part of our life here.  As skiers, we are sorry that they are receding now, but who knows what they will do long term?

Regards,

Max

I incorrectly said that the glaciers were 15% smaller than TODAY at their lowest point in the MWP.

This is not right.

They were 15% lower than the MAXIMUM length reached during the LIA, around 1850.

For example, Switzerland's largest glacier, the Aletsch, has a length of 23.6 km today, compared with the LIA maximum of 26.1 km in 1850, so it has shrunk by around 10% in length.  Around 900 years ago it reached a minimum length of around 22 km.  This is around 15% below the LIA maximum, and not 15% below today's length, as I said.

The calculated glacier surface or total volume in Gt of ice, have, of course, fluctuated even more that just the measured length. I believe the total volume loss of the Aletsch since 1850 has been estimated to be around one-third, or 13 Gt.  It has been calculated to be around 27 Gt today.

Regards,

Max

Yeah.  That's apparently what the record shows.

Regards,

Max

Very slow change is much more easily adaptable than fast change.  When the climate has changed rapidly over the past few thousand years, societies have been wiped out.  Read Linden's book Winds of change for a good description of climate as a "serial killer of civilizations."  

Today we're facing a possible rate and magnitude of climate change that we have not seen since the rise of modern society in the last few hundred years ... which is why the experts judge a significant risk of serious impacts.

"The warming over the last 10,000 years has been about 8 deg C.  That translates into a rate of about 0.1 per century."

Actually, it doesn't.

There was not a gradual, slow warming over the past 10,000 years.

Believe it is general knowledge that there were many periods of warming as well as cooling over the 10,000-year period, as the record shows there were periods of glacial advance and retreat.

I cannot tell you what the warming or cooling rate was in each of these periods, but a rate of 1 deg C per century could certainly have been possible. I have not seen any scientific evidence refuting this possibility.  

Regards,

Max

I agree that the Earth has warmed and cooled over the last 20,000 years, but at a rate slow compared to today.  

Over the next 100 years, the Earth might warm at a rate that is unprecedented over the last 20,000 years.  This is documented in the IPCC report.  If you disagree with that, please tell me your data source so I can fact-check it.

In the past, climate change has destroyed civilizations.  See Linden's book, Winds of change for a good description of this.

The rapid warming of the next century poses a substantial risk of serious climate impacts.  This is described in the recent IPCC report.  For small warmings, rich countries will do OK, but for big warmings, even the richest countries will suffer extensive declines in standard of living and virtually any other metric you can think of.

Thanks for link to Svensmark book.  Will check it out.

The discovery of an ancient quiver near a receding glacier is fascinating.

I'm no expert on this, and don't claim to be, but it looks like there are a lot of people out there, like yourself, working on "keeping them honest" (as CNN would say).

Regards,

Max

"Over the next 100 years, the Earth might warm at a rate that is unprecedented over the last 20,000 years."

I believe the key work here is "MIGHT".

Show me the EVIDENCE (not an IPCC report) that this is a realistic assessment.

Regards,

Max

Remind me John Bailo,
Since when has Henrik Svensmarks works ever been scientifically reproduced and validated?

"There is only one credible source here, and it's the IPCC."

Andrew, I would like to believe that you are right, and I guess I did a few years ago.

But the IPCC has done a lot to lose its credibility by predicting exaggerated temperature increases and disaster scenarios (floods, hurricanes, droughts, etc.), by creating and using questionable paleoclimate reconstructions to back up claims of "unprecedented 20th century warmth", by ignoring any data that do not support its predictions of impending disaster and by bending the facts - always in the same direction.

I do not want to get into a detailed discussion of each of the above points; they have been covered by many people, including some distinguished scientists, already.  

I also do not want to get into a debate on "which scientist said what when, and was it `peer-reviewed' and has it since been refuted by another scientist defending the `mainstream position', etc."

I just want to point out that IPCC loses credibility through one-sided reporting, hyperbole and exaggeration.

Below is a quote from an IPCC defender on another blogsite:

"I agree with you that IPCC may be wrong in a lot of particulars, and at least judging from the media report - insufficiently humble regarding their ability to predict specific effects.

The high-end of IPCC are a bit too high, and I think even IPCC says it's unlikely."

Hyperbole and exaggeration are what I would expect from a group of politicians that are trying to gather support for a cause.

It is not what I expect from a scientific study group that is supposed to be giving us an unbiased report.

If even the supporters agree that IPCC exaggerates, it is difficult for a neutral observer to consider them the "only one credible source".

I believe that it is important to get as many opinions as possible; we cannot rely on the IPCC to give us "all sides of the story" since they are the political representatives of only one side: "disastrous man-made global warming".

Regards,

Max

Since when has Henrik Svensmarks works ever been scientifically reproduced and validated.

Do you know who Ignatius J. Reilly is? Just curious. I imagine you in East Kent, WA, resplendent in your green ear-flapped hat, eating hot dogs and railing against the obscenities displayed on Grist.

Max-

One thing I've noticed is that the people who criticize the IPCC most are the least likely to have ACTUALLY READ IT.  

If you take the time to read the report, I think you'll find that it does not contain any of the "exaggerated" claims.  Do you even know what the IPCC says about hurricanes?  I sincerely doubt it.  

As I said aboveThose opposed to action on climate change MUST attack the IPCC.  Not doing so would completely destroy their position.  That explains the comments above that attempt to cast doubt on the IPCC by suggesting it is made up of politicians, etc.I recommend you read the report yourself.    

Just to remind everyone reading this, the IPCC is the opinion of the scientific community.  As I said above, but seems to need repeating:The IPCC report was written by hundreds of climate experts from 130 countries and was based on peer-reviewed scientific literature. The report has itself undergone several layers of scrutiny; it was evaluated by thousands of other climate experts, critiqued by over a hundred IPCC-member governments, and open to public review.

The IPCC's previous report, released in 2001 with similar conclusions, was reviewed and endorsed by a blue ribbon panel of the National Academy of Sciences, and its conclusions were subsequently endorsed by the American Meteorological Society, the American Geophysical Union, the American Association for the Advancement of Science, and others. These groups are not composed of a bunch of funding hungry scientists screaming that the sky is falling, but rather distinguished researchers stating that the Earth is warming. Think about this. How often can you get at least 100 professionals, such as doctors or lawyers, to agree on any complex problem?

In the end, the IPCC reports are perhaps the most thoroughly vetted documents in the history of science. These reports are therefore widely regarded as the most authoritative summaries of what we know about global warming and how confidently we know it.Thus, the IPCC is the most authoritative statement of what we know and how confidently we know it.

Let's compare to the IPCC report to the books that jbailo is hawking ("chilling stars" or "unstoppable global warming"): I'm sure they both have footnotes.  But does having footnotes automatically make something credible?  The IPCC has many more --- so by that metric, the IPCC wins.  Have these books been peer reviewed by hundreds of scientists?  No.  Have they been endorsed by a blue-ribbon panel of the U.S. National Academy? No.  Have their conclusions been endorsed by the American Geophysical Union?  No.  

I think it's clear what the credible source of information on climate change.

PS: this also goes for all the press releases and web sites that jbailo links to.  These have not undergone multiple layers of review ... so they cannot compare to the IPCC in terms of credibility.

I would also like to point out that having footnotes and references itself is not a guarantee for quality. Take Mr Lomborg's book. Plenty of footnotes and references yet when you actually take the effort of looking up these references you find they have often been quoted out of context or sometimes do not even exist.

Reply to Andrew Dessler

"I recommend you read the report yourself"

Yes, Andrew, I have read it many times.  

Have you?

"Do you even know what the IPCC says about hurricanes?  I sincerely doubt it."  

Andrew, your "sincere doubts" are unfounded. It says, among other things:

Under "Intense tropical cyclone activity increases":
"Likelihood that trend occurred in late 20th century (typically post 1960)" is
"Likely in some regions since 1970"
with a
"Likelihood of human contribution to observed trend" of
"More likely than not"
and the
"Likelihood of future trends based on projections for 21st century using SRES scenarios"of
"Likely"

Did you catch that part when YOU read it?

This is pure conjecture and hyperbole.

Makes people think they are giving unbiased input and know what they are talking about (both of which are not correct).

Check the NOAA records and you'll see that nine of the ten deadliest hurricanes in the USA occurred before 1960, with Katrina (#3 in deaths) the only one since then.

Of the 25 deadliest US tornadoes, none occurred after 1955. Of the 30 deadliest US tornados, only 2 occurred after 1980.

Outside the USA tropical storms have also not increased since 1980.

What does the IPCC have to say about that?  Is it "likely" or "very likely" that deadly hurricanes and tornadoes occurred more frequently before man-made global warming than afterward?

Whether IPCC says it is "likely" or "more likely" is sort of hypothetical, because it is TRUE FACT.

The same unfounded  "scare scenario" statements are made for droughts, heavy precipitation events, heat waves and increased incidence of extreme high sea levels.

Do you REALLY believe this hyperbole?

I don't, because it is purely based on conjecture.

I'm sorry, Andrew, but this is not an unbiased scientific report.  It is a scare scenario dressed up as "science". And, yes, Andrew.  I have read this report "ad nauseum".

This is what makes the IPCC report less than credible, and why we need other opinions.

Regards,

Max

Would the increase in quality of forecasting not have something to do with the lower casualty rates of storms and tornadoes? These days everybody knows days in advance when the storm is going to hit. There are tornado warnings and sophisticated radar systems. There are fewer surprises today. I don't think it has anything to do with fewer tornadoes or storms...

Reply to MarkUK

"I don't think it has anything to do with fewer tornadoes or storms..."

Give me the facts, not just what you "think".

Regards,

Max

Max-

I apologize for thinking you hadn't read the report.  However, several of the things you've said are so misinformed that it's an understandable mistake.

So, the report says:
Under "Intense tropical cyclone activity increases":
"Likelihood that trend occurred in late 20th century (typically post 1960)" is
"Likely in some regions since 1970"
with a
"Likelihood of human contribution to observed trend" of
"More likely than not"
and the
"Likelihood of future trends based on projections for 21st century using SRES scenarios"of
"Likely"Since "likely" means a 2 out of 3 chance a statement is correct, and "more likely than not" means a 51% chance, then (speaking as a scientist) these statements sum up nicely the peer-reviewed research on this topic.  

Note that these express weak confidence since scientists generally consider 95% (19 in 20) to be a robust conclusion.  

You might disagree, but these IPCC statements are carefully vetted by the authors of the report, the expert scientists who peer review the report, the member governments, etc. etc.  Thus, they are the credible assessment of the scientific community.  

As you yourself said up above, you're not an expert.  Why should anyone believe you over the IPCC?  

Reply to Andrew Dessler.

"Since "likely" means a 2 out of 3 chance a statement is correct, and "more likely than not" means a 51% chance, then (speaking as a scientist) these statements sum up nicely the peer-reviewed research on this topic.  
Note that these express weak confidence since scientists generally consider 95% (19 in 20) to be a robust conclusion."

In other words, you are saying the IPCC has "weak confidence" that what they are predicting regarding more intense and frequent tropical storm activity is true (speaking as a scientist, that is).

So do I.

Look, Andrew, I do not doubt at all that many scientists, like yourself, agree with IPCC's more disastrous predictions.

You must also agree that some others do not. Whether this is 49%, 20% or even just 10% does not really matter.

I just think IPCC has lost credibility by using too much exaggeration and hyperbole, and by "bending the facts". You obviously do not.

IPCC does not have the "monopoly" on climate science, regardless of what you may say. The IPCC report does not by itself represent the only "credible assessment of the scientific community".

I believe there will be someone way out there on the fringes like Einstein or Copernicus at the time (will it be Svensmark?) that suddenly comes up with a whole new theory that shoots all the IPCC model predictions down the drain, no matter how much "these statements sum up nicely the peer-reviewed research on this topic".

So I do not believe you have been able to convince me that "There is only one credible source here, and it's the IPCC."

And that is what this whole discussion is all about.

Regards,

Max

Thanks for tornado report.  It looks convincing, except for caveat:

"Tornadoes prior to 1953 were UNDER-REPORTED.  A national tornado data collection process was put into place in 1953.  Some of the recent increased number of reported tornadoes is due to increased public and media awareness and reporting of tornadoes.  That is, not all of the recent increase in tornado reports is real."

The NOAA statistics are real, but I agree with you, that we now have better ways to avert disaster from tornadoes than before 1950.

Regards,

Max

1) I would estimate that only a few scientists really disagree with the IPCC, and I'm sure we could name them in a few minutes: Lindzen, Singer, Pielke, Michaels, and a few others.  Several thousand scientists agree with the IPCC.

I'm sure that if you went back a few years, you'd find a similar split on the "does smoking cause cancer" question.

2) You continue to sayI just think IPCC has lost credibility by using too much exaggeration and hyperbole, and by "bending the facts". You obviously do not.but you haven't identified any exaggeration.  The statement by the IPCC about hurricanes (in particular the confidence estimates) is completely consistent with the peer-reviewed scientific literature.  

What you need to realize is that advocates misrepresent what the IPCC says as a strategy to  paint it as an extremist document.  But if you read the actual report, you'll find it is sober and backed by peer-reviewed science.

3) I believe there will be someone way out there on the fringes like Einstein or Copernicus at the time (will it be Svensmark?) that suddenly comes up with a whole new theory that shoots all the IPCC model predictions down the drain, no matter how much "these statements sum up nicely the peer-reviewed research on this topic".The IPCC estimates that it is very likely that humans are responsible for most of the recent warming.  In other words, there's about a 10% chance that our understanding of the climate is wrong in some fundamental way.  On the other hand, we're 90% sure that we're right.  Which are you going to bet on?

Message to John Mashey

John,

You'll be glad to here that there is new snow on the Pizol.

Won't do the skiers much good anymore, though, since the old gondola is shut down and the new one won't be ready until 2008.

Regards,

Max

Reply to Andrew Dessler

Andrew, let's see if we can wind up this conversation before it becomes too repetitive.

"On the other hand, we're 90% sure that we're right.  Which are you going to bet on?"

Most folks (scientists included) usually think they are 90% (or even more) sure they are right.  Peer-review by folks that all believe the same thing is more like rubber-stamping.

I told you I do not want to get into a discussion with you on nitty gritty details.  It's a waste of time for us both.

The IPCC report is a one-sided document, regardless of what you may think or believe. Its whole purpose is to alarm people that we are headed for a disaster due to anthropogenic greenhouse gases.

There are a lot of almost legalese sounding caveats sprinkled around like "likely", "very likely", "high level of confidence", "low level of scientific understanding", but no where do I see "This report and the conclusions reached are a summary of work done by many scientists and, to the best of our knowledge it is a realistic assessment.  There are, however, other scientific studies and conclusions that disagree with our position that anthropogenic global warming should be a major concern or even exists at all as a significant factor, and that show that there are still far too many unknowns to make any realistic predictions for the future.  While we disagree with these other scientific opinions, we realize that no one can be absolutely sure what the real cause is for current trends and, even less, what the future will bring."

We are living in a democratic society, not a totalitarian one.  Being fed as "truth" a computer model based scientific report by people who are "90% sure they are right" and do not even admit that there is another side to the story cannot be the end of it. That is not the way democracy works.

It is important that we have all sides to look at, not just one.

And yes, Andrew, even "non-scientists" can have the common sense to figure out what is hyperbole and exaggeration.

Regards,

Max

Max,

For the avoidance of doubt I was not really trying to make any point regarding an increase in tornado frequency. I am not sure actually what the story is regarding tornadoes and global warming. Dr Dessler, do you know anything about forecasts regarding tornadoes?

The IPCC report is a one-sided document, regardless of what you may think or believe. Its whole purpose is to alarm people that we are headed for a disaster due to anthropogenic greenhouse gases.For this to be true, there has to be a massive conspiracy that includes: thousands of scientists, 130 member governments, the U.S. National Academy of Sciences, the American Geophysical Union, the American Meteorological Association, the American Association for the Advancement of Science, etc., etc.

The other possibility is you're wrong --- and the IPCC does represent the opinion of the scientific community.

I don't want to sound elitist, but frankly there's only one side to the debate over human-induced AGW.  You keep saying that there's another side, but I have not seen any evidence that supports that.  The examples you've given about exaggeration of the IPCC simply don't hold up --- it is not an alarmist document, but soberly assesses what the scientific community thinks is true.

You can make the IPCC sound alarmist by misquoting it, but if you actually read what it says (e.g., about hurricanes), you see that it's statements are quite reasonable.

If there is another side to the debate, WHERE IS IT?

PS: MarkUK: I don't know if we have a good handle on trends in tornadoes.