Category Archives: Skeptic Summaries

Good Video

I enjoyed this video from CO2 Science and the Idso family.   It has much more in-depth science than most climate videos. For those of you who judge scientific issues based on ad hominem factors, the Idso’s are on ExxonSecret’s S-list, having had the temerity to accept Exxon money at some point in the past. For the rest of you, I think the video is good and worth the price.

Reminder: November 10 Phoenix Climate Presentation

I am making this reminder in honor of Blog Action Day for Climate.

I would like to invite all of you in the Phoenix area to my climate presentation on November 10, 2009. The presentation is timed to coincide with the Copenhagen climate negotiations as Ill as debate on the Boxer cap-and-trade bill in the US Senate.

Despite the explosion of media stories on climate, it is difficult for the average person to really get a handle on the science of greenhouse gasses and climate change in the simplistic and often incomplete or even incorrect popular accounts. This presentation, which is free to the public, will focus on the science of climate change, including:

  • Why greenhouse gasses like CO2 warm the Earth.
  • How most forecasts of warming from manmade causes are grossly exaggerated, which helps to explain why actual temperatures are undershooting warming forecasts
  • How natural processes lead to climate variations that are being falsely interpreted as man-made.
  • A discussion of public policy initiatives, and the presentation of a much lower-cost alternative to current cap-and-trade bills
  • A review of the role of amateurs in weather and climate measurement, and how the average person can get involved

I have a degree in mechanical and aerospace engineering from Princeton University and a masters degree from Harvard. Most of his training is in control theory and the forecasting of complex dynamic systems, which turn out to be the key failure points in most catastrophic climate forecasts. My mission over the last few years both at this web site and my lectures and debates has been to teach the science of global warming in ways that are accessible to the general public.

Over the years I have preferred a debate format, as for example in my debate with Joe Nation, the author of California’s cap-and-trade law. Unfortunately, the most alarmist proponents of catastrophic manmade global warming have taken Al Gore’s lead and refuse to participate in public debates on the topic. As a result, I will do my best to be fair in presenting the global warming case, and then show which portions are really “settled science” and which portions are exaggerated. You are encouraged to check out to see the type of issues I take on – there are links to past presentations, blog posts, books, and even a series of popular and highly-rated YouTube videos.

Below you will also find an example of the types of issues I will discuss. There are many, many folks out there on both sides of this issue whose writing and presentations amount to little more than fevered finger-pointing – I work hard to avoid this type rhetoric and focus on the science.

The presentation will be at 7PM November 10 in the auditorium of the Phoenix Country Day School, just north of Camelback on 40th Street, and is free to the public (this event is paid for me personally and is not sponsored or paid for by any group). The presentation will be about an hour long with another hour for questions and discussion. Folks on all sides of these issues are encouraged to attend and participate in civil discussion of the issues.

If you are interested, please join the mailing list for this presentation to receive reminders and updates:

Example Climate Issue: Positive Feedback

By Warren Meyer

I often make a wager with my audiences. I will bet them that unless they are regular readers of the science-based climate sites, I can tell them something absolutely fundamental about global warming theory they have never heard. What I tell them is this:

Man-made global warming theory is not one theory but in fact two totally separate theories chained together. These two theories are:

  1. Man-made greenhouse gasses, such as CO2, acting alone will warm the planet betIen 1.0 and 1.5 degrees Celsius by the year 2100.
  2. The Earth’s climate system is dominated by positive feedbacks, such that the warming from Greenhouse gasses alone is amplified 3-5 or more times. Most of the warming in catastrophic forecasts comes from this second effect, not directly from greenhouse gas warming.

This is not some Iird skeptic’s fantasy. This two-part description of catastrophic global warming theory is right out of the latest IPCC report. Most of the warming in the report’s forecasts actually results from the theory of positive feedback in #2, not from greenhouse gasses directly.

One of the most confusing issues for average people watching the climate debate is how one side can argue so adamantly that the science is “settled” and the other can argue just the opposite. The explanation lies in large part with this two-part theory. There is a high degree of consensus around proposition1, even among skeptics. I may disagree that the warming is 0.8C or 1.2C, but few on the science end of the debate would argue that CO2 has no effect on warming. When people say “the science is settled” they generally want to talk about proposition 1 and avoid discussion of proposition 2.

That is because proposition 2 is far from settled. The notion that a long-term stable system can be dominated by very high positive feedbacks offends the intuition of many natural scientists, who know that most natural processes (short of nuclear fission) are dominated by negative feedbacks. Sure, there are positive feedbacks in climate, just as there are negative feedbacks. The key is how these net out. The direct evidence that the Earth’s climate is dominated by strong net positive feedbacks is at best equivocal, and in fact evidence is growing that negative feedbacks may dominate, thus greatly reducing expected future warming from greenhouse gasses.

In my public presentations, I typically will

  • Explain this split of catastrophic man-made global warming theory into two propositions, and how most of the predicted catastrophe comes from the second proposition rather than the first
  • Show how skeptics have hurt their credibility by trying to challenge proposition #1
  • Explain the mechanics in simple terms of positive and negative feedback
  • Show the data and evidence related to feedback
  • Show from historic temperature numbers that assumptions of high positive feedback are extremely unlikely to be correct.

I have a video related to these issues of feedback and forecasts on YouTube in a 9 minute video titled “Don’t Panic – Flaws in Catastrophic Global Warming Forecasts.” See all my videos at my YouTube channel.

The Single Best Reason Not To Fear a Climate Catastrophe

Apparently this is Blog Action Day for Climate.  The site encourages posts today on climate that will be aggregated, uh, somehow.  Its pretty clear they want alarmist posts and that the site is leftish in orientation (you just have to look at the issues you can check off that interest you — lots of things like “societal entrepreneurship” but nothing on individual liberty or checks on government power).  However, they did not explicitly say “no skeptics” — they just want climate posts.  So I will take the opportunity today to post a number of blasts from the past, including some old-old ones on Coyote Blog.

While the science of how CO2 and other greenhouse gases cause warming is fairly well understood, this core process only results in limited, nuisance levels of global warming. Catastrophic warming forecasts depend on added elements, particularly the assumption that the climate is dominated by strong positive feedbacks, where the science is MUCH weaker. This video explores these issues and explains why most catastrophic warming forecasts are probably greatly exaggerated.

You can also access the YouTube video here, or you can access a higher quality version on Google video here.

If you have the bandwidth, you can download a much higher quality version by right-clicking either of the links below:

I am not sure why the quicktime version is so porky.  In addition, the sound is not great in the quicktime version, so use the windows media wmv files if you can.  I will try to reprocess it tonight.  All of these files for download are much more readable than the YouTube version (memo to self:  use larger font next time!)

Phoenix Climate Presentation, November 10 at 7PM

I have given a number of presentations on climate change around the country and have taken the skeptic side in a number of debates, but I have never done anything in my home city of Phoenix.

Therefore, I will be making a presentation in Phoenix on November 10 at 7PM in the auditorium of the Phoenix Country Day School, on 40th Street just north of Camelback. Admission is free. My presentation is about an hour and I will have an additional hour for questions, criticism, and rebuttals from the audience.

I will be posting more detail later, but the presentation will include background on global warming theory, a discussion of why climate models are likely exaggerating future warming, and an evaluation of various policy alternatives. The presentation will be heavy on science and data, but is meant to be accessible without a science background. I will post more details of the agenda as we get closer to the event.

I am taking something of a risk with this presentation. I am paying for the auditorium and promotion myself — I am not doing this under the auspices of any group. However, I would like to get good attendance, in part because I would like the media representatives attending to see the local community demonstrating interest in at least giving the skeptic side of the debate a hearing. If you are a member of a group that might like to attend, please email me directly at the email link at the top of this page and I can help get more information and updates to your group.

Finally, I have created a mailing list for folks who would like more information about this presentation – just click on the link below. All I need is your name and email address.

Potential Phoenix Climate Presentation

I am considering making a climate presentation in Phoenix based on my book, videos, and blogging on how catastrophic anthropogenic global warming theory tends to grossly overestimate man’s negative impact on climate.

I need an honest answer – is there any interest out there in the Phoenix area in that you might attend such a presentation in North Phoenix followed by a Q&A?  Email me or leave notes in the comments.  If you are associated with a group that might like to attend such a presentation, please email me.

Interview with John Christy

Blogging has been really light here because

  1. I have this real job thingie which sometimes demands my time
  2. My blogging time is consumed at CoyoteBlog on what I consider more pressing issues than 100-year temperature changes (including real, immediate threats to the rule of law by an Administration trying to convert an economic slump into an excuse for extensive government interventionism).
  3. To the extent I am blogging on climate, it is generally not on the science  (not a lot to write about right now — the same problems with AGW theory still exist) but on regulatory issues, which I tend to address at Coyote Blog rather than here.

However, while I am a bit dormant, this is a nice interview with John Christy.   Not a ton new here for frequent readers of science-based skeptic sites.

Ducking the Point

Most skeptics have been clubbed over the head with the “settled science” refrain at one time or another.  How can you, a layman, think you are right when every scientist says the opposite?  And if it is not settled science, how do folks get away unchallenged saying so?

I am often confronted with these questions, so I thought I would print my typical answer.  I wrote this in the comments section of a post at the Thin Green Line.  Most of the post is a typical ad hominem attack on skeptics, but it includes the usual:

The contrarian theories raise interesting questions about our total understanding of climate processes, but they do not offer convincing arguments against the conventional model of greenhouse gas emission-induced climate change.

Here is what I wrote in response:

I am sure there are skeptics that have no comprehension of the science that blindly follow the pronouncements of certain groups, just as I am sure there are probably as high a percentage of global warming activists who don’t understand the science but are following the lead of sources they trust. The only thing I will say is that there is a funny dynamic here. Those of us who run more skeptical web sites tend to focus our attention on deconstructing the arguments of Hansen and Schmidt and Romm, who alarmist folks would consider their top spokesmen. Many climate alarmists in turn tend to focus on skeptical buffoons. I mean, I guess its fun to rip a straw man to shreds, but why not match your best against the best of those who disagree with you?

Anyway, I am off my point. There is a reason both sides can talk past each other. There is a reason you can confidently say “well established and can’t be denied” for your theory and be both wrong and right at the same time.

The argument that manmade CO2 emissions will lead to a catastrophe is based on a three step argument.

  1. CO2 has a first order effect that warms the planet
  2. The planet is dominated by net positive feedback effects that multiply this first order effect 3 or more times.
  3. These higher temperatures will lead to and already are causing catastrophic effects.

You are dead right on #1, and skeptics who fight this are truly swimming against the science. The IPCC has an equation that results in a temperature sensitivity of about 1.2C per doubling of CO2 as a first order effect, and I have found little reason to quibble with this. Most science-based skeptics accept this as well, or a number within a few tenths.

The grand weakness of the alarmist case comes in #2. It is the rare long-term stable natural physical process that is dominated by positive feedback, and the evidence that Earth’s climate is dominated by feedbacks so high as to triple (in the IPCC report) or more (e.g. per Joe Romm) the climate sensitivity is weak or in great dispute. To say this point is “settled science” is absurd.

So thus we get to the heart of the dispute. Catastrophists posit enormous temperature increases, deflecting criticism by saying that CO2 as a greenhouse gas is settled. Though half right, they gloss over the fact that 2/3 or more of their projected temperature increase is based on a theory of Earth’s climate being dominated by strong positive feedbacks, a theory that is most certainly not settled, and in fact is probably wrong. Temperature increases over the last 100 years are consistent with neutral to negative, not positive feedback, and the long-term history of temperatures and CO2 are utterly inconsistent with the proposition there is positive feedback or a tipping point hidden around 350ppm CO2.

So stop repeating “settled science” like it was garlic in front of a vampire. Deal with the best arguments of skeptics, not their worst.

I see someone is arguing that skeptics have not posited an alternate theory to explain 20th century temperatures. In fact, a number have. A climate sensitivity to CO2 of 1.2C combined with net negative feedback, a term to account for ENSO and the PDO, plus an acknowledgment that the sun has been in a relatively strong phase in the second half of the 20th century model temperatures fairly well. In fact, these terms are a much cleaner fit than the contortions alarmists have to go through to try to fit a 3C+ sensitivity to a 0.6C historic temperature increase.

Finally, I want to spend a bit of time on #3.  I certainly think that skeptics often make fools of themselves.  But, because nature abhors a vacuum, alarmists tend to in turn make buffoons of themselves, particularly when predicting the effects on other climate variables of even mild temperature increases. The folks positing ridiculous catastrophes from small temperature increases are just embarrassing themselves.

Even bright people like Obama fall into the trap. Earlier this year he said that global warming was a factor in making the North Dakota floods worse.

Really? He knows this? First, anyone familiar with the prediction and analysis of complex systems would laugh at such certainty vis a vis one variable’s effect on a dynamic system. Further, while most anything is possible, his comment tends to ignore the fact that North Dakota had a colder than normal winter and record snowfalls, which is what caused the flood (record snows = record melts). To say that he knows that global warming contributed to record cold and snow is a pretty heroic assumption.

Yeah, I know, this is why for marketing reasons alarmists have renamed global warming as “climate change.” Look, that works for the ignorant masses, because they can probably be fooled into believing that CO2 causes climate change directly by some undefined mechanism. But we here all know that CO2 only affects climate through the intermediate step of warming. There is no other proven way CO2 can affect climate. So, no warming, no climate change.

Yeah, I know, somehow warming in Australia could have been the butterfly flapping its wings to make North Dakota snowy, but by the same unproven logic I could argue that California droughts are caused by colder than average weather in South America. At the end of the day, there is no way to know if this statement is correct and a lot of good reasons to believe Obama’s statement was wrong. So don’t tell me that only skeptics say boneheaded stuff.

The argument is not that the greenhouse gas effect of CO2 doesn’t exist. The argument is that the climate models built on the rickety foundation of substantial positive feedbacks are overestimating future warming by a factor of 3 or more. The difference matters substantially to public policy. Based on neutral to negative feedback, warming over the next century will be 1-1.5C. According to Joe Romm, it will be as much as 8C (15F). There is a pretty big difference in the magnitude of the effort justified by one degree vs. eight.

New Climate Video – RCRC Climate Debate

I have finally been able to publish a video of my presentation at the climate debate held by the Regional Council of Rural Counties last September.  The entire video is about an hour long.  As usual, I am offering several ways to view it.  First, it has been posted on YouTube but had to be broken into seven parts.  The playlist of all seven parts is below:

The playlist link is here:  RCRC Climate Debate (Skeptic's Side)

Unfortunately, YouTube crushes the resolution so many of the charts are hard to read.  You can download the full resolution windows media version (about 96MB) as long as my bandwidth holds out by right-clicking and downloading form this link:  Download RCRC Climate Debate (wmv)

Also, you can stream higher resolution version of this film (and all my other climate films) at this site.  The resolution is not as good as the downloadable version but is much better than YouTube.  Again, bandwidth pending.

Finally, you can download the actual powerpoint presentation shown in this video here or you can view the presentation online here.

In the future, all of my videos and presentations will be available via the links just under the banner for this site.

Sun, PDO, and CO2

For those who have not seen it, Roy Spencer has a new paper on the PDO, clouds and temperature history.

I have never explicitly stated this, but my sense is that medium to long scale 20th century temperature trends can be explained mostly through three drivers:

1.  A cyclical variation driven by multi-decade oceanic cycles like the Pacific Decadal Oscillation (PDO):


2.  Changes in solar output, either directly as increased heating or indirectly via a variety of theories on things like cosmic rays and cloud formation:


3.  A long term trend of up to +0.05C per decade that may include a CO2-warming component. 

I am willing to posit a CO2 impact net of feedbacks of perhaps 0.5-1.0C over the next century.  This may appear low, but is the only scale of number reasonably supported by history.  Any higher number would result in temperatures way too high historically.  And even assuming a number this high runs into the following problem:  There was probably a trend of about this magnitude emerging from the little ice age 200+ years ago and extending into the 20th century.  You can see it in the glacier numbers below:  (source)


Those that want to assign the temperature trend, once the sun and the PDO are removed, post-1950 to CO2, need to explain what effect was causing the nearly exact same trend from 1800-1950, and why that trend conveniently switched off at the exact moment man's CO2 takes over.  In the context of the glacier chart, what was causing the glaciers to retreat in 1880, and why is that effect not the one at work today?

Global Warming … Accelerating?

A week or two ago a “study” by the World Wildlife Fund got a lot of play in the media.  Its key conclusion:

The report says that the 2007 report from the Intergovernmental Panel on Climate Change (IPCC) – a study of global warming by 4,000 scientists from more than 150 countries which alerted the world to the possible consequences of global warming – is now out of date.

WWF’s report, Climate Change: Faster, stronger, sooner, has updated all the scientific data and concluded that global warming is accelerating far beyond the IPCC’s forecasts.

As an example it says the first tipping point may have already been reached in the Arctic where sea ice is disappearing up to 30 years ahead of IPCC predictions and may be gone completely within five years – something that hasn’t occurred for 1m years. This could result in rapid and abrupt climate change rather than the gradual changes forecast by the IPCC.

This is not at all an uncommon meme.  If one searches “global warming accelerating” on Google, one gets 1,100,000 hits.  The #1 hit says:

Global warming is accelerating three times more quickly than feared, a series of startling, authoritative studies has revealed.

I actually believe there is a small upward temperature trend due to CO2, on the order of 0.05 – 0.1C per decade.  But it is staggering to me that so many people can insist, with a straight face, that warming is “accelerating” or, crazier, that it is “worse than forecast.”

Let’s take the acceleration first.  Here is the recent temperature trend from the UAH satellite data (all the smoothed lines you will see are 36-month moving averages centered on the middle month).


It is possible to argue that there is a warming trend here, but never-the-less it is impossible to see “acceleration,” particularly since 2001.  There is an implication in the article that the acceleration has occurred since the last couple of IPCC reports, so let’s zoom into the period since the 3rd and 4th IPCC reports:


No acceleration.  Not even any warming  (for 8 years!  where is that story in the press?)

But how about the proposition that temperatures are rising faster than forecasts?  This is patently absurd.  We can go back to just about every IPCC and alarmist projection and show that temperatures are well less than forecast, but lets use James Hansen’s forecasts to Congress in 1988 because it gives us 20 years of data to work with (actual data is a blend of Hadley CRUT3 and UAH satellite as discussed here.)


I always get folks who insist that I am making a mistake by using the Hansen A scenario because Hansen at the time described it as extreme.  But in fact, world CO2 production has been even greater than the Hansen A scenario.  Hansen A underestimates the inputs, and still grossly overestimates the output.  The only real discussion one can find on the IPCC forecasts is whether one can argue the actuals are barely poking their nose up into the low end of the forecast confidence intervals or not.

The one piece of evidence most of these folks making the “accelerating” argument use is sea ice extent in the North Pole.  The media has been full of stories about disappearing sea ice, and in fact in 2007 the North Pole had the lowest sea ice extent in the last 30 years, though coincidently in the same year the South Pole had the highest sea ice extent in 30 years.  But there is a logical fallacy here.  The fact that the statement “global warming causes sea ice to retreat” is true does not mean the statement “sea ice retreat means the globe is warming” has to be true.  And in fact, we see from the data above, this is not true.  It is amazing to me that in the conflict between “thermometers” and “sea ice extent at one pole” as measures for global temperature, sea ice extent seems to trump thermometer readings.  Particularly when this sea ice signal only exists at one of the two poles.

There is no question that the Arctic has warmed more than the rest of the planet.  In fact, much of the rise in global averages is driven by the Arctic  (and all of it is driven by the norther hemisphere above the tropics — the rest of the world has no warming signal over the last 30 years).  Below we can see the satellite measurement of the temperature anomaly in the Arctic:


A one degree rise over a couple of decades is indeed substantial.  In fact, though, during the last couple of years, we have actually seen either flat temperatures or, perhaps, a cooling trend.  Here is a closeup:


So it might be that we should look for other explanations of unusually large sea ice retreats in the summers of 2007 and 2008.  It has been suggested by NASA that winds and ocean currents are in part to blame, and by others that black carbon deposits on the ice from Chinese coal plants may also be increasing summer melt.

Whatever the case, there are a lot of good reasons to believe we are not seeing an “acceleration” in global warming.  And a lot of very, very good reasons to believe we are not reaching a “tipping point.”  Tipping point implies that we have entered a regime where the climate is dominated by runaway positive feedback.  I have addressed this topic many times, and will not address it right now, but in short all of the catastrophe in climate models is due not to the assumption of CO2 as a greenhouse gas (which actually tends to yield modest warming in models) but the assumption that the Earth’s climate is dominated by substantial positive feedbacks.  I discuss the entire topic of positive feedbacks and climate forecasts in the video below:

Update – if we add glaciers here in addition to sea ice, we see the same slow retreating trend.  However, the trend goes back 200 years!  That’s 150 years longer than man has been producing substantial CO2 emissions.  (source)


RCRC Climate Presentation

I made a 30-minute presentation to the California Regional Council of Rural Counties yesterday.   The audience was mainly county supervisors and other officials from about 30 rural counties.  The presentation was the skeptical counterpoint to a presentation by Joe Nation, who among other accomplishments was an author of AB32, the California global warming abatement law.  Download RCRC_Global_Warming_Presentation_update_Sept-25-2008.ppt .  Some of the charts may not be self-explanatory, so I am working on a YouTube video with my speech overlaid on the slides.

It was an interesting experience for me because the audience was hugely sympathetic to my pitch, but frustrated because, for them, it was beside the point:  They were already committed by AB32 to take drastic and expensive action under AB32.  The only policy recommendation I made in my speech was to lament the obsession with cap-and-trade and make a plea for a carbon tax.  The discussion afterward pretty much made my point for me, with every member lamenting the absurdities that are emerging in the CARB regulation process.  Even Mr. Nation admitted that the CARB is setting up programs that are preferentially regulating those with the least political muscle and pushing policies which make no sense in any kind of cost-benefit analysis for fighting CO2.  Mr. Nation said that when he was in the legislature, he tried a carbon tax first but could not get it out of committee, even a small one that would have raised gas taxes about 5 cents.  It seems politicians have no problem enacting huge taxes (which is what AB32 does) as long as those taxes are not called a tax and are hidden from the view of the general public (at least until prices start to rise and businesses start to exit the state).

I thought Mr. Nation did a perfectly reasonable job, and I agreed with much of what he presented.  I differed only, of course, in the amount of past warming I was willing to ascribe to CO2 and the amount of future warming from CO2 that we might expect.  However, this was the first time I have ever seen a global warming catastrophist be explicit that CO2 only causes a bit of future warming, and that most is from positive feedbacks multiplying the greenhouse effect.  Kudos for him for highlighting this, and this certainly fed into my pitch well.

The one area where I thought he made an explicit factual mistake in his presentation was in evaluating Hansen’s forecast to Congress in 1988.  He argued that one shouldn’t judge Hansen by his "A" scenario (which is WAY off) because Hansen said at the time that this was based on unrealistically high assumptions.  But in Hansen’s appendix, he says that the A scenario is based on 1.5% a year future growth in CO2 output.  In fact, the world has grown CO2 output by 1.75 % a year in the last 20 (source), so in fact the A scenario is, if anything, low.  The B and C scenarios should be treated as totally irrelevant.  This is a mistake I think Lucia made at the Blackboard, considering B and C at all.  These scenarios differ in their CO2 forecasts, not the model parameters, so the scenario closest to actual CO2 output should be chosen and the rest are irrelevant.  By the way, here is my chart.  As I did with many of my charts, I like to counterpoint the data against media reports (the box in the upper left).  This helps later in the discussion when the disconnect people have between what I have said and what they have heard inevitably crops up.


I was pleased that Russ Steele of NC Media Watch was there to say hi and observe the proceedings.  Thanks Russ — I enjoy your blog and am sorry that I did not recognize you in my pre-presentation stress. 

Update:  Russ has a more complete roundup of the discussion

Update 2:  The actuals in the chart above are UAH satellite numbers, with the anomaly shifted up about 0.1C to match zero values with the Hansen forecast data.

Practically A Summary of this Blog

In a letter of support for Lord Monckton’s recent paper in the Newsletter of the American Physical Society, APS member Roger Cohen summarized his disagreeements with the IPCC position on global warming in what could easily have been the table of contents for this blog:

I retired four years ago, and at the time of my retirement I was well convinced, as were most technically trained people, that the IPCC’s case for Anthropogenic Global Warming (AGW) is very tight. However, upon taking the time to get into the details of the science, I was appalled at how flimsy the case really is. I was also appalled at the behavior of many of those who helped produce the IPCC reports and by many of those who promote it. In particular I am referring to the arrogance; the activities aimed at shutting down debate; the outright fabrications; the mindless defense of bogus science, and the politicization of the IPCC process and the science process itself.

At this point there is little doubt that the IPCC position is seriously flawed in its central position that humanity is responsible for most of the observed warming of the last third of the 20th century, and in its projections for effects in the 21st century. Here are five key reasons for this:

  1. The recorded temperature rise is neither exceptional nor persistent. For example, the earth has not warmed since around 1997 and may in fact be in a cooling trend. Also, in particular, the Arctic and contiguous 48 states are at about the same temperature as they were in the 1930s. Also in particular the rate of global warming in the early 20th century was as great as the last third of the century, and no one seriously ascribes the early century increase to greenhouse gas emissions.
  2. Predictions of climate models are demonstrably too high, indicating a significant overestimate of the climate sensitivity (the response of the earth to increases in the incident radiation caused by atmospheric greenhouse gases). This is because the models, upon which the IPCC relies for their future projections, err in their calculations of key feedback and driving forces in the climate system.
  3. Natural effects have been and continue to be important contributors to variations in the earth’s climate, especially solar variability and decadal and multidecadal ocean cycles.
  4. The recorded land-based temperature increase data are significantly exaggerated due to widespread errors in data gathering and inadequately corrected contamination by human activity.
  5. The multitude of environmental and ecological effects blamed on climate change to date is either exaggerated or nonexistent. Examples are claims of more frequent and ferocious storms, accelerated melting of terrestrial icecaps, Mount Kilimanjaro’s glacier, polar bear populations, and expansive mosquito-borne diseases. All of these and many others have been claimed and ascribed to global warming and by extension to human activity, and all are bogus or highly exaggerated.

via Anthony Watts

Roy Spencer Congressional Testimony

I am a bit late on this, but Roy Spencer raises a number of good issues here in his testimony to Congress.  In particular, he focuses on just how much climate alarmists’ assumption of strong positive feedback drive catastrophic forecasts.  Put in more realistic, better justified feedback assumptions, and the catastrophe goes away.

Testimony of Roy W. Spencer before the
Senate Environment and Public Works Committee on 22 July 2008

A printable PDF of this testimony can be found here

I would like to thank Senator Boxer and members of the Committee for allowing me to discuss my experiences as a NASA employee engaged in global warming research, as well as to provide my current views on the state of the science of global warming and climate change.

I have a PhD in Meteorology from the University of Wisconsin-Madison, and have been involved in global warming research for close to twenty years. I have numerous peer reviewed scientific articles dealing with the measurement and interpretation of climate variability and climate change. I am also the U.S. Science Team Leader for the AMSR-E instrument flying on NASA’s Aqua satellite.

1. White House Involvement in the Reporting of Agency Employees’ Work

On the subject of the Administration’s involvement in policy-relevant scientific work performed by government employees in the EPA, NASA, and other agencies, I can provide some perspective based upon my previous experiences as a NASA employee. For example, during the Clinton-Gore Administration I was told what I could and could not say during congressional testimony. Since it was well known that I am skeptical of the view that mankind’s greenhouse gas emissions are mostly responsible for global warming, I assumed that this advice was to help protect Vice President Gore’s agenda on the subject.

This did not particularly bother me, though, since I knew that as an employee of an Executive Branch agency my ultimate boss resided in the White House. To the extent that my work had policy relevance, it seemed entirely appropriate to me that the privilege of working for NASA included a responsibility to abide by direction given by my superiors.

But I eventually tired of the restrictions I had to abide by as a government employee, and in the fall of 2001 I resigned from NASA and accepted my current position as a Principal Research Scientist at the University of Alabama in Huntsville. Despite my resignation from NASA, I continue to serve as Team Leader on the AMSR-E instrument flying on the NASA Aqua satellite, and maintain a good working relationship with other government researchers.

2. Global Warming Science: The Latest Research
Regarding the currently popular theory that mankind is responsible for global warming, I am very pleased to deliver good news from the front lines of climate change research. Our latest research results, which I am about to describe, could have an enormous impact on policy decisions regarding greenhouse gas emissions.
Despite decades of persistent uncertainty over how sensitive the climate system is to increasing concentrations of carbon dioxide from the burning of fossil fuels, we now have new satellite evidence which strongly suggests that the climate system is much less sensitive than is claimed by the U.N.’s Intergovernmental Panel on Climate Change (IPCC).

Another way of saying this is that the real climate system appears to be dominated by “negative feedbacks” — instead of the “positive feedbacks” which are displayed by all twenty computerized climate models utilized by the IPCC. (Feedback parameters larger than 3.3 Watts per square meter per degree Kelvin (Wm-2K-1) indicate negative feedback, while feedback parameters smaller than 3.3 indicate positive feedback.)

If true, an insensitive climate system would mean that we have little to worry about in the way of manmade global warming and associated climate change. And, as we will see, it would also mean that the warming we have experienced in the last 100 years is mostly natural. Of course, if climate change is mostly natural then it is largely out of our control, and is likely to end — if it has not ended already, since satellite-measured global temperatures have not warmed for at least seven years now.

2.1 Theoretical evidence that climate sensitivity has been overestimated
The support for my claim of low climate sensitivity (net negative feedback) for our climate system is two-fold. First, we have a new research article1 in-press in the Journal of Climate which uses a simple climate model to show that previous estimates of the sensitivity of the climate system from satellite data were biased toward the high side by the neglect of natural cloud variability. It turns out that the failure to account for natural, chaotic cloud variability generated internal to the climate system will always lead to the illusion of a climate system which appears more sensitive than it really is.

Significantly, prior to its acceptance for publication, this paper was reviewed by two leading IPCC climate model experts – Piers Forster and Isaac Held– both of whom agreed that we have raised a legitimate issue. Piers Forster, an IPCC report lead author and a leading expert on the estimation of climate sensitivity, even admitted in his review of our paper that other climate modelers need to be made aware of this important issue.

To be fair, in a follow-up communication Piers Forster stated to me his belief that the net effect of the new understanding on climate sensitivity estimates would likely be small. But as we shall see, the latest evidence now suggests otherwise.

2.2 Observational evidence that climate sensitivity has been overestimated
The second line of evidence in support of an insensitive climate system comes from the satellite data themselves. While our work in-press established the existence of an observational bias in estimates of climate sensitivity, it did not address just how large that bias might be.

But in the last several weeks, we have stumbled upon clear and convincing observational evidence of particularly strong negative feedback (low climate sensitivity) from our latest and best satellite instruments. That evidence includes our development of two new methods for extracting the feedback signal from either observational or climate model data, a goal which has been called the “holy grail” of climate research.
The first method separates the true signature of feedback, wherein radiative flux variations are highly correlated to the temperature changes which cause them, from internally-generated radiative forcings, which are uncorrelated to the temperature variations which result from them. It is the latter signal which has been ignored in all previous studies, the neglect of which biases feedback diagnoses in the direction of positive feedback (high climate sensitivity).
Based upon global oceanic climate variations measured by a variety of NASA and NOAA satellites during the period 2000 through 2005 we have found a signature of climate sensitivity so low that it would reduce future global warming projections to below 1 deg. C by the year 2100. As can be seen in Fig. 1, that estimate from satellite data is much less sensitive (a larger diagnosed feedback) than even the least sensitive of the 20 climate models which the IPCC summarizes in its report. It is also consistent with our previously published analysis of feedbacks associated with tropical intraseasonal oscillations3.

Fig. 1. Frequency distributions of feedback parameters (regression slopes) computed from three-month low-pass filtered time series of temperature (from channel 5 of the AMSU instrument flying on the NOAA-15 satellite) and top-of-atmosphere radiative flux variations for 6 years of global oceanic satellite data measured by the CERES instrument flying on NASA’s Terra satellite; and from a 60 year integration of the NCAR-CCSM3.0 climate model forced by 1% per year CO2 increase. Peaks in the frequency distributions indicate the dominant feedback operating. This NCAR model is the least sensitive (greatest feedback parameter value) of all 20 IPCC models.
A second method for extracting the true feedback signal takes advantage of the fact that during natural climate variability, there are varying levels of internally-generated radiative forcings (which are uncorrelated to temperature), versus non-radiative forcings (which are highly correlated to temperature). If the feedbacks estimated for different periods of time involve different levels of correlation, then the “true” feedback can be estimated by extrapolating those results to 100% correlation. This can be seen in Fig. 2, which shows that even previously published4 estimates of positive feedback are, in reality, supportive of negative feedback (feedback parameters greater than 3.3 Wm-2K-1).

Fig. 2. Re-analysis of the satellite-based feedback parameter estimates of Forster and Gregory (2006) showing that they are consistent with negative feedback rather than positive feedback (low climate sensitivity rather than high climate sensitivity).

2.3 Why do climate models produce so much global warming?
The results just presented beg the following question: If the satellite data indicate an insensitive climate system, why do the climate models suggest just the opposite? I believe the answer is due to a misinterpretation of cloud behavior by climate modelers.

The cloud behaviors programmed into climate models (cloud “parameterizations”) are based upon researchers’ interpretation of cause and effect in the real climate system5. When cloud variations in the real climate system have been measured, it has been assumed that the cloud changes were the result of certain processes, which are ultimately tied to surface temperature changes. But since other, chaotic, internally generated mechanisms can also be the cause of cloud changes, the neglect of those processes leads to cloud parameterizations which are inherently biased toward high climate sensitivity.

The reason why the bias occurs only in the direction of high climate sensitivity is this: While surface warming could conceivably cause cloud changes which lead to either positive or negative cloud feedback, causation in the opposite direction (cloud changes causing surface warming) can only work in one direction, which then “looks like” positive feedback. For example, decreasing low cloud cover can only produce warming, not cooling, and when that process is observed in the real climate system and assumed to be a feedback, it will always suggest a positive feedback.
2.4 So, what has caused global warming over the last century?
One necessary result of low climate sensitivity is that the radiative forcing from greenhouse gas emissions in the last century is not nearly enough to explain the upward trend of 0.7 deg. C in the last 100 years. This raises the question of whether there are natural processes at work which have caused most of that warming.
On this issue, it can be shown with a simple climate model that small cloud fluctuations assumed to occur with two modes of natural climate variability — the El Nino/La Nina phenomenon (Southern Oscillation), and the Pacific Decadal Oscillation — can explain 70% of the warming trend since 1900, as well as the nature of that trend: warming until the 1940s, no warming until the 1970s, and resumed warming since then. These results are shown in Fig. 3.

Fig. 3. A simple climate model forced with cloud cover variations assumed to be proportional to a linear combination of the Southern Oscillation Index (SOI) and Pacific Decadal Oscillation (PDO) index. The heat flux anomalies in (a), which then result in the modeled temperature response in (b), are assumed to be distributed over the top 27% of the global ocean (1,000 meters), and weak negative feedback has been assumed (4 W m-2 K-1).

While this is not necessarily being presented as the only explanation for most of the warming in the last century, it does illustrate that there are potential explanations for recent warming other that just manmade greenhouse gas emissions. Significantly, this is an issue on which the IPCC has remained almost entirely silent. There has been virtually no published work on the possible role of internal climate variations in the warming of the last century.

3. Policy Implications
Obviously, what I am claiming today is of great importance to the global warming debate and related policy decisions, and it will surely be controversial. These results are not totally unprecedented, though, as other recently published research6 has also led to the conclusion that the real climate system does not exhibit net positive feedback.

While it will take some time for the research community to digest this new information, it must be mentioned that new research contradicting the latest IPCC report is entirely consistent with the normal course of scientific progress. I predict that in the coming years, there will be a growing realization among the global warming research community that most of the climate change we have observed is natural, and that mankind’s role is relatively minor.

While other researchers need to further explore and validate my claims, I am heartened by the fact that my recent presentation of these results to an audience of approximately 40 weather and climate researchers at the University of Colorado in Boulder last week (on July 17, 2008 ) led to no substantial objections to either the data I presented, nor to my interpretation of those data.

And, curiously, despite its importance to climate modeling activities, no one from Dr. Kevin Trenberth’s facility, the National Center for Atmospheric Research (NCAR), bothered to drive four miles down the road to attend my seminar, even though it was advertised at NCAR.

I hope that the Committee realizes that, if true, these new results mean that humanity will be largely spared the negative consequences of human-induced climate change. This would be good news that should be celebrated — not attacked and maligned.

And given that virtually no research into possible natural explanations for global warming has been performed, it is time for scientific objectivity and integrity to be restored to the field of global warming research. This Committee could, at a minimum, make a statement that encourages that goal.

1. Spencer, R.W., and W.D. Braswell, 2008: Potential biases in cloud feedback diagnosis:
A simple model demonstration. J. Climate, in press.
2. Allen, M.R., and D.J. Frame, 2007: Call off the quest. Science, 318, 582.
3. Spencer, R.W., W. D. Braswell, J. R. Christy, and J. Hnilo, 2007: Cloud and radiation
budget changes associated with tropical intraseasonal oscillations. Geophys. Res.
Lett., 34, L15707, doi:10.1029/2007GL029698.
4. Forster, P. M., and J. M. Gregory, 2006: The climate sensitivity and its components
diagnosed from Earth Radiation Budget data. J. Climate, 19, 39-52.
5. Stephens, G. L., 2005: Clouds feedbacks in the climate system: A critical review. J.
Climate, 18, 237-273.
6. Schwartz, S. E., 2007: Heat capacity, time constant, and sensitivity of the Earth’s
climate system. J. Geophys. Res., 112, D24S05, doi:10.1029/2007JD008746.

Working on New Videos

Sorry posting has been light, but I am working on starting a new series of videos.  At some point I want to update the old ones, but right now I want to experiment with some new approaches — the old ones are pretty good, but are basically just powerpoint slides with some narration.  If you have not seen the previous videos, you may find them as follows:

  • The 6-part, one hour version is here
  • The 10-minute version, which is probably the best balance of time vs. material covered, is here.
  • The short 3-minute version I created for a contest (I won 2nd place) is here.

Combined, they have over 40,000 views.

Climate Blogs That Don’t Necessarily Accept “The Consensus”

Via Tom Nelson and Climate Debate Daily

William M. Briggs
Climate Audit
Climate Change Facts
Climate Change Fraud
Climate Police
Climate Resistance
Climate Scam
Climate Science
CO2 Science
Friends of Science
Global Climate Scam
Global Warming Heretic
Global Warming Hoax
Global Warming Skeptic
Greenie Watch
Bruce Hall
Warwick Hughes
Lucia Liljegren
Jennifer Marohasy
Warren Meyer
Maurizio Morabito
Luboš Motl
Tom Nelson
Newsbusters climate
Planet Gore
Roger Pielke Sr.
Fred Singer
David Stockwell
Philip Stott
Anthony Watts
World Climate Report

Earth Day Thoughts

Cross-Posted from Coyote Blog

Happy Birthday Vladimer Lenin Earth Day.  I have a few thoughts for the day:

Sucking the Oxygen Out of the Environmental Movement

Observe today how little of the discussion is about anything other than climate.  There are still many environmental issues in the world that can be improved by the application of man’s effort and technology — unfortunately, climate is the least of these but the issue getting the most attention.  Consider how the global warming panic has sucked the oxygen out of the environmental movement.  Ten years from now, I predict that true environmentalists will be looking back on the hysteria over trace amounts of CO2 in the atmosphere as a huge setback for real environmental progress.

Environmentalism and Socialism

If you attend any Earth Day events today, notice how many of the speeches and presentations and such are anti-corporate, anti-trade, anti-capitalist, anti-wealth screeds, and have little to do with the environment.  If you actually go to a live Earth Day event, you will see why the selection of Lenin’s birthday was no accident.  You will not see this on the network news, because the media is sympathetic to the environmental movement and tends to edit the socialist rants out as PR protection for the environmentalists, knowing that American audiences would lose sympathy for them if they listened to the whole package. (This is mostly an American phenomenon – I have found from my brief travels in Europe that the media there does less such editing, perhaps because they know their audience is more comfortable with socialism).

The Climate Denier Trick

There are a lot of reasons not to be worried about "inaction" on global warming.  To justify the enormously expensive cuts in CO2 productions, on the order of 80% as supported by Obama and Clinton, one has to believe every element of a five-step logic chain:

  1. Mankind is increasing CO2 concentrations in the atmosphere
  2. Increased atmospheric CO2 causes the world to warm (by some amount, large or small)
  3. The increases in CO2 from man will cause substantial warming, large enough to be detectable above natural climate variations
  4. The increases in world temperatures due to man’s CO2 will have catastrophic impacts on civilization
  5. These catastrophic impacts and their costs are larger than the enormous costs, in terms of poverty and lost wealth, from reducing CO2 with current technologies.

Climate alarmists have adopted a rhetorical trick that no one in the media seems willing to call them on.   They like to wage the debate over global warming policy on points one and two only, skipping over the rest.  Why?  Because the science behind numbers one and two are pretty strong.  Yes, there are a few folks who will battle them on these points, but even very strong skeptics like myself accept points one and two as proved. 

Here are some examples of how this trick works.  If, like me, you do not accept steps 3-4-5 in the above logic chain, you will be called a "denier."  When asked what a denier means, a climate alarmist will often position this denial as somehow disputing #1 and #2.  On the other hand, if one publicly accepts #1 and #2, the alarmist will shout "QED" and then proceed to say that strong action on CO2 is now justified.  When an alarmist says that the a consensus exists, he is probably correct on points 1 and 2.  But he is absolutely incorrect that a consensus exists on 3-4-5.

Don’t believe me?  Think back to the early Republican debate, where the moderator asked for a show of hands whether [I can’t remember the exact question] man was causing global warming.  The implication is that you either have to accept this whole logic chain or not.  One can see why Fred Thompson begged to have 90 seconds to explain his position, and why the moderator, presumably in the alarmist camp, denied it to him. 

Over the last year or two, skeptics have gotten a lot better at making their argument.  Most all of them, like I do, begin their arguments by laying out a logic chain like this and explaining why one can believe that man-made greenhouse gases cause warming without accepting the need for drastic climate action.  The result?  Alarmists have stopped debating, and/or have declared that the debate is "over."  Remember that last great Al Gore climate debate?  Neither do I.

The Single Best Reason Not To Be Worried About Climate

I could, and have, in my books and videos, made arguments on many points in 3-4-5 (links at the bottom of the post).  In four, no one ever considers the good effects of warming (e.g. on growing seasons and crop yields) and most every other problem is greatly exaggerated, from hurricane formation to sea level rises.  And in five, every time someone has tried to put a price on even small reductions in CO2, the numbers are so enormous that they are quickly suppressed by a environmentalist-sympathetic media.  Suffice it to say that even the climate-sanctimonious Europeans have not been willing to pay the price for even slowing down their CO2 growth (which has risen faster than in the US), much less reducing it.

But in this logic chain, there is little need to argue about four and five if #3 is wrong.  And it is.

The effects of CO2 acting alone on temperatures are quite small — And everyone, even the alarmists, agree!  A doubling of CO2 concentrations, without other effects that we will discuss in a moment, will heat the earth no more than about 1 degree Celsius (though several studies recently have argued the number is much less).  This is not some skeptic’s hallucination — this is straight out of the IPCC third and fourth assessments [IPCC text quoted here].  In fact, the IPCC in their reports has steadily reduced their estimate of the direct contribution of CO2 on temperatures.  CO2, acting alone, warms the Earth only slowly, and at this rate we would see less than a degree of warming over the next century, more of a nuisance than a catastrophe.

But some scientists do come up with catastrophic warming forecasts.  They do so by assuming that our Earth’s climate is dominated by positive feedbacks that multiply the initial warming from CO2 by a factor of three, four, five or more.  This is a key point — the catastrophe does not come from the science of greenhouse gases, but from separate hypotheses that the earth’s climate is dominated by positive feedback. This is why saying that greenhouse gas theory is "settled" is irrelevant to the argument about catastrophic forecasts.  Because these positive feedbacks are NOT settled science.

In fact, the IPCC admits it does not even know the sign of the most important effect (water vapor), much less its magnitude.  They assume that the net effect is positive, and in fact strongly so – on the order of 60-80% feedback or more, nearly unprecedented numbers for a long-term stable physical system [more on feedback and its math here].  This is particularly ironic because alarmist Michael Mann, with his hockey stick, famously posited that temperatures over the last 1000 years were incredibly flat and stable until man started burning fossil fuels, a proposition that is hard to believe if the climate is dominated by strong positive feedback.   Note that when people like Al Gore say things like "tipping point," they are in effect hypothesizing that feedback is greater than 100%, meaning that climate can be a runaway process, like nuclear fission.

In fact, with the 100 or so years of measurements we have for temperature and CO2, empirical evidence does not support these high positive feedbacks. Even if we assign all the 20th century warming to CO2, which is unlikely, our current warming rates imply close to zero feedback.  If there are other causes for measured 20th century warming other than CO2, thereby reducing the warming we blame on CO2, then the last century’s experience implies negative rather than positive feedback in the system.  As a result, it should not be surprising that high feedback-driven forecasts from the 1990 IPCC reports have proven to be way too high vs. actual experience (something the IPCC has since admitted).

However, climate scientists are unwilling to back down from the thin branch they have crawled out on.  Rather than reduce their feedback assumptions to non-catastrophic levels, they currently hypothesize a second man-made cooling effect that is masking all this feedback-driven warming.  They claim now that man-made sulfate aerosols and black carbon are cooling the earth, and when some day these pollutants are reduced, we will see huge catch-up warming.  If anything, this cooling effect is even less understood than feedback.  What we do know is that, unlike CO2, the effects of these aerosols are short-lived and therefore localized, making it unlikely they are providing sufficient masking to make catastrophic forecasts viable.  I go into several reality checks in my videos, but here is a quick one:  Nearly all the man-made cooling aerosols are in the northern hemisphere, meaning that most all the cooling effect should be there — but the northern hemisphere has actually exhibited most of the world’s warming over the past 30 years, while the south has hardly warmed at all.

In sum, to believe catastrophic warming forecasts, one has to believe both of the following:

  1. The climate is dominated by strong positive feedback, despite our experience with other stable systems that says this is unlikely and despite our measurements over the last 100 years that have seen no such feedback levels.
  2. Substantial warming, of 1C or more, is being masked by aerosols, despite the fact that aerosols really only have strong presence over 5-10% of the globe and despite the fact that the cooler part of the world has been the one without the aerosols.

Here’s what this means:  Man will cause, at most, about a degree of warming over the next century.  Most of this warming will be concentrated in raising minimum temperatures at night rather than maximum daytime temperatures  (this is why, despite some measured average warming, the US has not seen an increase of late in maximum temperature records set).  There are many reasons to believe that man’s actual effect will be less than 1 degree, and that whatever effect we do have will be lost in the natural cyclical variations the climate experiences, but we are only just now starting to understand.

To keep this relatively short, I have left out all the numbers and such.  To see the graphs and numbers and sources, check out my new climate video, or my longer original video, or download my book for free.

Update: Very relevant article by Roy Spencer on the over-estimation of feedback in climate models.

Many of us, especially those who were trained as meteorologists, have long questioned the climate research community’s reliance on computerized climate models for global warming projections.  In contrast to our perception that the real climate system is constantly readjusting to internal fluctuations in ways that stabilize the system, climate models built upon measured climate behavior invariably suggest a climate system that is quite sensitive – sometimes catastrophically sensitive — to perturbations such as those from anthropogenic greenhouse gas emissions.  Unfortunately, it has been difficult to articulate our ‘hand-waving’ concerns in ways that the modelers would appreciate, i.e., through equations.   

After years of pondering this issue, and after working on our two latest papers on feedbacks (Spencer et al., 2007; Spencer and Braswell, 2008, hereafter SB08), I believe that I can now explain the main reason for this dichotomy.   Taking the example of clouds in the climate system, the issue can be introduced in the form of a question:

To what extent are climatic variations in clouds caused by temperature change (feedback), versus temperature change being the result of cloud variations?