Pat'n Chip float by WUWT on a cloud of aerosols

Patrick J Michaels and Paul C. "Chip" Knappenberger have discovered a new blog article about aerosols. The article is by Dr Nicolas Bellouin from the University of Reading, who specialises in studying aerosols. He wrote about a preliminary estimate of aerosol-cloud forcing of -0.6 W m^-2, which is lower than the estimate in the latest IPCC report, of -0.9 W m^-2, but well within the range in the IPCC report, which is quite wide - from -1.9 to -0.1 W m^-2.

Pat'n Chip grabbed hold of the blog article as though it were precious gold, and published at WUWT (archived here).  Deniers haven't got much to grab hold of right now, so a blog article about a blog article will have to do. The first blog article is not yet a paper. That's promised for August this year. In fact, at the bottom of his article, Dr Bellouin wrote:

I thank Graham Feingold, Johannes Quaas, Annica Ekman, Leo Donner, and Ilan Koren for interesting discussions on current understanding of aerosol-cloud interactions. Note that they do not all agree that aerosol-cloud radiative forcing is weak: some argue that a value of up to −1.2 W m^-2 remains consistent with scientific understanding.

That value of −1.2 W m^-2 is higher than the lower end referred to in the IPCC report (−1.9 W m^-2), so it could be that the range has been better defined in the three years since the AR5 IPCC report.

No pause in the frenzy of denial: at WUWT

Anthony Watts wrote about the new NOAA paper in Science that: "WUWT has already found the fatal weakness in the paper". Already he's published two protest articles. We're still waiting. There's not a mention of any "fatal weakness".

As I wrote in the main article about it, the new paper describes an analysis of global surface temperature trends, and shows that the trend in surface temperature this century is indistinguishable from that for the second half of last century. Global warming continues at the surface. There is no "hiatus".

On Seeps and SCAMS Part II: Pat'n Chip'n David Fake a Debate.

In Part I of On Seeps and SCAMS, I wrote about the new paper on how denialist talking points can influence climate science. A day or so ago, there was an article at WUWT (archived here), by Patrick J. Michaels and Paul C. “Chip” Knappenberger (Pat'n Chip), in which they commented on that paper. Their WUWT article had the title: Lewandowsky’s Competing Theories for Source of Bias in Scientific Research. [This is Part II of a three part series. Click for Part I and Part III.]

The title was misleading. Pat'n Chip's WUWT article was more a promo for another article by David E. Wojick and Patrick J. Michaels. Their's is not a scientific paper, it's a CATO article. It would take a huge stretch of imagination to consider the denier lobby group, CATO, to have any relation to science.

What they wrote about could have been an interesting topic I suppose, though it demonstrates a naive view of the world on the part of the authors. They were ostensibly exploring whether or not government funding can bias research. Their paper had the title:

Is the Government Buying Science or Support?

A Framework Analysis of Federal Funding-induced Biases

They claim:

The research question is clear: does biased funding skew research in a preferred direction, one that supports an agency mission, policy or paradigm?

The reason I say it could have been an interesting topic is that research that is primarily funded by government is subject to the vagaries of government priorities. Not in the results, but in what areas research is undertaken.

A silly poster by Pat'n Chip at AGU14 provides a learning experience

Anthony Watts has reported a poster (archived here). He doesn't comment on it. I doubt he understands it. Most of the people commenting at WUWT don't understand it either. And I don't blame them.

Now I'm no Tamino, however in my view, what Pat Michaels and Chip Knappenberger have done, ostensibly, is flawed from the outset and demonstrates that they don't understand the CMIP5 climate models.

Rather than show a chart with observations vs models (combined), what they've done is show a chart of trend changes. That's fine, but further down I'll explain why I believe the conclusions they draw are flawed.

More double standards at WUWT: Not one person asked to see the data from Pat'n Chip

It looks as if Anthony Watts is getting his marching orders from the CATO Institute this week. First there was Paul Driessen wanting to "bring back smog". Now we've got the disinformer duo, Patrick J. Michaels and his sidekick, Paul C. "Chip" Knappenberger - affectionately known as Pat 'n Chip (archived here). What this pair is trying to tell us is that what the IPCC report said about a "hiatus" is reflected in science papers about the so-called "hiatus" in global surface temperatures. They are in essence claiming the IPCC was correct. (Actually, to sell their story to the deniers, Pat'n Chip made up stuff about what the IPCC report actually said, pretending it said something different so they could argue the point. It's called building a strawman.)

What pause? There is no pause in global warming!

Remember, a "slow down" (or even the poorly named "hiatus") in global surface temperature does not in any way signify a pause in global warming. The earth continues to warm up. This year even the global surface temperatures are setting new records.

Data source: NASA GISS - including average year to date to October 2014.

Tree ring growth vs latewood density: Pat'n Chip get lost in the forest at WUWT

Anthony Watts has a "guest essay" by Pat'n Chip (archived here, latest update here), the duo from the CATO Institute. (Part of their job seems to be to spread disinformation about climate science. It's a good lark. Money for jam. They don't have to do much except spend a few minutes every now and then writing stuff and nonsense.)

Today's serving has a woody flavour. They are claiming that a new paper in GRL, by Martin Tingley and colleagues, contradicts a paper by Michael Mann. Michael Mann says, no. That's wrong.

To summarise

As suggested by Steve Bloom in the comments, here are the main points as I see them:

• Tree ring growth reconstructions do not register the sudden (short-lived) drop in temperature following very large volcanic eruptions of the past millennia. This has implications for estimates of climate sensitivity based on paleoclimatology. (Mann12)
• Latewood density measures exaggerate the drop in temperature following large-ish recent volcanic eruptions, Krakatau and Novarupta. (Tingley14)
• The new paper by Martin Tingley et al complements, rather than contradicts, the 2012 paper by Mann et al. 
• In dendrochronology, density is not the same as tree ring growth and one does not necessarily follow the same pattern as the other.

Initial impressions

Before I discovered Michael Mann's Huff Post article, I looked at the Mann paper and the abstract of the Tingley paper and at first glance it looked to me as if the papers were about different things. Or at least about different volcanic eruptions. I had some questions, though, because both papers were looking at how the sign of a temperature drop after large volcanic eruptions are manifested in tree rings.

So I went to the Tingley paper itself. It's not open access, so unless you can get hold of a copy, you'll have to take what I write at face value. Or you can read what Michael Mann has written about this at Huffington Post.

WUWT quote of the day from Paul C. "Chip" Knappenberger

Seen today. Chip Knappenberger (half of the Pat'n Chip denier duo of the Cato Institute) is quoted in a copy and paste at WUWT:

...there are a lot more cases of non-extreme weather than there are of extreme weather.

Duh!

Ain't that obvious? Nuts for brains!

Heat kills! Pat'n Chip argue for survival of the wealthiest at WUWT

Paul C. “Chip” Knappenberger and Patrick J. Michaels (Pat'n Chip) keep plugging away at their weird notion that no matter how hot it gets, humans will adapt and fewer will die from heat-related causes.  Here is part of what they write at WUWT (archived here):

The cause of the observed decline in the sensitivity to extreme heat in the face of rising heat is likely found in a collection of adaptations including increased access to air-conditioning, better medical care, improved building design, community response programs, heat watch/warning systems, and biophysical changes. There is no reason to think that such response measures won’t continue to exist and be improved upon into the future.In our recent study summarizing the findings on declining heat-related mortality trends in both the U.S and Europe, we made this observation (Knappenberger et al., 2014):

Credit: Plognark

So everyone who lives somewhere that's affected by heatwaves, make sure you upgrade your air conditioner and try to find one that will work at 47°C plus. (I picked that number because I once had to drive my car in 47°C heat for half an hour or so to try to get the air conditioner fixed. I don't know how I made it without passing out. Also, I'm sure I'm not the only one whose home air conditioner is only rated to 43°C, the best we could find at the time.)

Not that your air-conditioner will do you much good when the power goes out because either it's broken down or can't cope with the stress on the system, caused by the heat wave. Heat can kill hundreds of people in a single heat wave. Maybe Pat'n Chip live in a very mild climate.

Make sure your local hospital is equipped to cope with the influx of people who get caught in future heat waves (those that don't collapse and die on the spot). And don't forget to boost your paramedic services. Hospitals won't help if you can't get there.  Stuff more insulation in your ceiling space and walls and don't go outside, whatever you do. Even if that means you get the sack from your job or your sports team (see also here).

I really don't know why Pat'n Chip keep beating this dead horse. Where I live there is a big spike in the number of deaths in a heat wave. Horrid heat is not something you want to inflict on anyone, unless you're like Pat'n Chip who don't care about those suffering the heat in India or South America or Australia or elsewhere.

Although it hasn't happened yet, as the world warms it's conceivable that large areas could become uninhabitable. That's not because of heat alone. It's because when temperatures soar enough alongside humidity then it exceeds the physiological tolerance of humans. This was described by two researchers a few years ago. Stephen Sherwood from the University of New South Wales and Matthew Huber from Purdue University did the maths and this is documented clearly and succinctly in their abstract:

Despite the uncertainty in future climate-change impacts, it is often assumed that humans would be able to adapt to any possible warming. Here we argue that heat stress imposes a robust upper limit to such adaptation. Peak heat stress, quantified by the wetbulb temperature TW, is surprisingly similar across diverse climates today. TW never exceeds 31 °C. Any exceedence of 35 °C for extended periods should induce hyperthermia in humans and other mammals, as dissipation of metabolic heat becomes impossible. While this never happens now, it would begin to occur with global-mean warming of about 7 °C, calling the habitability of some regions into question. With 11–12 °C warming, such regions would spread to encompass the majority of the human population as currently distributed. Eventual warmings of 12 °C are possible from fossil fuel burning. One implication is that recent estimates of the costs of unmitigated climate change are too low unless the range of possible warming can somehow be narrowed. Heat stress also may help explain trends in the mammalian fossil record.

So although it would be quite a few decades before global temperatures rise 7 °C, there will still likely be parts of the world where those conditions could arise for short periods of time later this century. Particularly if we don't reduce carbon emissions enough.

Heat waves don't just kill people directly. They also affect the ability to supply electricity, they spark fires and cause them to turn into catastrophic killers, they dry up bodies of water and exacerbate drought. Heat is very pleasant in moderation. Too much of a good thing will kill.

I consider people like Pat'n Chip a menace to society.

From the WUWT comments

Eve doesn't give a rats for people who die in the heat and says:

June 20, 2014 at 7:36 pm
I have been freezing in Canada since I returned from the Bahamas. I have not had the quilt off since I arrived, plus having to wear long pants, long sleeves, no heat wave, just cold. Where is Obama that he is so hot? Tell him to turn down the heat.

Tom Harley is deluded about southern Australia. It can get much hotter down south than it does in the tropics. He says:

June 20, 2014 at 9:21 pm
Majormike1 is right, here in the tropical north of Australia, thousands of climate refugees are towing their camper vans, trailers and wotnot all over the region, clogging up the roads, hotels, resorts and camping grounds, just to get away from ‘the cold’ in the ‘Southern Australian States’.
Those of us who have lived here long enough, hate to leave here, even in the summer.
If you want your cold, you can keep your cold. Stay away Mr President. Bring global warming back, now. 

Eric Worrall suggests everyone move to beautiful Hervey Bay and says:

June 20, 2014 at 9:28 pm
I’ve got good news – when it gets too hot, here in Sunny Hervey Bay, 25 degrees south of the Equator, we wear shorts and t-shirts.
Hervey Bay has a lot of retired people, because of the year round pleasant climate, a lot like Florida. So far, heat related mortality does not seem to be an issue. 

---

Sherwood, Steven C., and Matthew Huber. "An adaptability limit to climate change due to heat stress." Proceedings of the National Academy of Sciences 107, no. 21 (2010): 9552-9555. doi: 10.1073/pnas.0913352107

About face at WUWT - backing off from denialism

The last couple of days have seen a few contradictions at WUWT. Or more properly, about faces. Par for the course for the denialati.

About face number 1 - Neukom2014 is "good science"

First up, I noticed that WUWT-ers at first didn't like the recent paper of Neukom et al which reconstructed surface temperatures of the southern hemisphere over the past 1000 years. Anthony tagged it as "bad science".  Wondering Willis wrote a couple of articles where he decided it was all wrong because Steve McIntyre said it was all wrong, and Willis agreed.  Their argument seems to have been that in their opinion, proxies are more reliable than modern thermometers, which seems a bit silly to me. If a potential proxy didn't reflect temperature as measured by a modern instrument then I'd be inclined to go with the modern instrument - wouldn't you?


It doesn't matter anyway because now Anthony Watts has done an about face. Neukom et al is no longer "bad science". It's very good science. The WUWT about face (archived here) is because of an article in Nature Climate Change by Kim Cobb, which is based on Neukom et al. Anthony Watts' headline is:

New paper finds climate sensitivity to CO2 is lower than previously believed, strong natural variability in Southern Hemisphere

Going by the excerpts published at WUWT, the article doesn't make that finding. It does suggest that climate sensitivity calculations based solely on Northern Hemisphere reconstructions may err on the high side.

If the new reconstruction of Southern Hemisphere temperature is accurate, then estimates of climate sensitivity — the response of global temperature change to a given amount of external radiative forcing — may be lower than those calculated based solely on Northern Hemisphere reconstructions10.  

Given that Anthony has now embraced Neukom et al, which said pretty much the same thing as Kim Cobb wrote, what does that mean for deniers? In particular, does it mean they will let go of their obsession with the medieval warm anomaly, which wasn't in much evidence down south? Does it mean they'll accept estimates of climate sensitivity that are based on global (as opposed to NH only) temperature reconstructions?

This is Figure 3 from the Neukom paper showing extreme warm and cold decadal temperatures. The third chart from the top is the combined northern and southern hemispheres. It's getting mighty hot:

About face number 2 - people can afford climate control

In what is a second about face by the denialiati, it's no longer the case that people will all die of cold when an ice age cometh.  I deduce that from Anthony being co-author of a comment to a paper about deaths from heat extremes in Stockholm County in Sweden. (I wrote about that paper several weeks ago.) Anthony and his co-authors are apparently arguing that people will adapt to hot weather by spending up big on air conditioners, therefore they won't die, unlike people in my home state of Victoria. (More people do die in heat waves in my home state. Anthony's only talking about Sweden. Perhaps people in Sweden are tougher.) And in any case, they argue, what about Urban Heat Islands.

The WUWT article is archived here. Pat'n Chip and Anthony's published comment can be read here. Anthony doesn't link to the reply by Åström and colleagues so I will - you can read it in its entirety I think on Readcube.

The main arguments of Pat'nChip and Anthony are:

• Stockholm temperatures aren't the same as global temperatures - which is an odd argument because the scientists didn't ever claim it was. It's irrelevant. They threw in "what about UHI" for good measure.
• People adapt to heat by getting cool.

The main response is (verbatim):

• The observed [temperature] changes are the result of natural processes, including regional climate variability, and anthropogenic influences, including urbanization.
• Our data indicate that there is no adaptation to heat extremes on a decadal basis or to the number of heat extremes occurring each year. Although another study observed a reduction in the population health impact of hot and cold extremes over the twentieth century, this decrease should not be confused with adaptation to climatic change.... 
• Whether future development pathways will continue to increase resilience will also depend on many factors other than climate change. Importantly, it is not appropriate to assume that historic trends will continue, with or without climate change.

There's more in the reply.

Anthony doesn't say what Swedish people do when it gets too hot for the air conditioners to work.  Or what happens when the power companies ration power because there isn't enough to go around with everyone running their new air conditioners full blast.

Anyway if, as Anthony maintains, poor people can afford to buy and run air conditioners when it gets too hot to handle, then they can presumably also afford to buy and run heaters in cold weather.

One thing is that everyone, including Pat'nChip and Anthony Watts are accepting the fact that Sweden is getting hotter. This regional warming is, needless to say, consistent with global warming.

---

Cobb, Kim M. "Palaeoclimate: A southern misfit." Nature Climate Change 4, no. 5 (2014): 328-329. doi:10.1038/nclimate2219

Neukom, Raphael, Joëlle Gergis, David J. Karoly, Heinz Wanner, Mark Curran, Julie Elbert, Fidel González-Rouco et al. "Inter-hemispheric temperature variability over the past millennium." Nature Climate Change 4, no. 5 (2014): 362-367. doi:10.1038/nclimate2174

Åström, Daniel Oudin, Bertil Forsberg, Kristie L. Ebi, and Joacim Rocklöv. "Attributing mortality from extreme temperatures to climate change in Stockholm, Sweden." Nature Climate Change 3, no. 12 (2013): 1050-1054. DOI: 10.1038/NCLIMATE2022

Knappenberger, Paul, Patrick Michaels, and Anthony Watts. "Adaptation to extreme heat in Stockholm County, Sweden." Nature Climate Change 4, no. 5 (2014): 302-303. doi:10.1038/nclimate2201 (full text here)

Åström, Daniel Oudin, Bertil Forsberg, Kristie L. Ebi, and Joacim Rocklöv. "Reply to'Adaptation to extreme heat in Stockholm County, Sweden'." Nature Climate Change 4, no. 5 (2014): 303-303. doi:10.1038/nclimate2202 (full text here)

Same old, same old from WUWT deniers

There's not been much happening in the climate denier blogosphere worth writing about with some exceptions, which I'll address in a future article.

Anthony Watts is copying and pasting some stuff from WUWT deniers like Larry Hamlin and paid disinformers like Pat 'n Chip, wailing that "all the models are wrong".  The same nonsense that Anthony wheels out when he runs out of ideas for new material.

It's nothing new.  They are trading on the false idea that global warming has stopped.  I guess they figure that they need to get in while they can because the slow down in global surface temperatures won't last.  And if the anticipated El Nino eventuates and it follows the pattern of previous ones, then next year would be hotter than any previous El Nino year, which would make it the hottest year on record. Hotter even than 2010. Which would mean the deniers would have to write about something else altogether to try to persuade the public that:

• global warming isn't happening, or
• if it is it's not bad, or 
• if it is bad, we'll adapt, or 
• if it is bad, some of us will adapt and
• if it is bad and some of us manage to adapt, it won't cost much to adapt, or 
• if it is bad and some of us manage to adapt and it does cost a lot to adapt then taxpayer's shouldn't have to pay to adapt - or 
• something.

I'm a bit too busy to go through their articles and arguments line by line, so I'll just put up a couple of charts that highlight the problem we are facing.  First, earth is still getting hotter as seen in multiple ways:

Next, we're not even close to cutting CO2 emissions yet.  And time is running out:

Adapted from IPCC AR5 WG1

Finally, from WGIII Summary for Policy Makers, the longer we wait the fewer options we'll have:

Delaying mitigation efforts beyond those in place today through 2030 is estimated to substantially increase the difficulty of the transition to low longer‐term emissions levels and narrow the range of options consistent with maintaining temperature change below 2°C relative to pre‐industrial levels.

From the WUWT comments

You'll all have read the empty protests, like those archived here and here before.  I won't bother picking holes in them - the IPCC reports themselves do that.  Here are some choice comments from the WUWT deniers to Pat 'n Chip's article (archived here):


Latitude opts for the fantastical climate hoax conspiracy theory favoured by many science deniers and says:

April 16, 2014 at 6:10 pm
Why do so many people discuss the science or computer models…without first acknowledging they are all based on fraudulent temperature records that have been fudged.
Even if they had invented the perfect model…they would never know it….because the models are all tuned to temp histories that have made the past colder and the present warmer….to show a faster rise in global warming…

They cooked their own goose with this one…they will never get an accurate computer model…with out first admitting they cooked the temp record

SIGINT EX is, I think, trying to be clever or funny or something and says:

April 16, 2014 at 7:42 pm
IPCC Titanic.
Do not trust the … “Captain” !
The “Watch Maker” turned “Ship Designer” on 2nd Deck standing by the spiral staircase and looking at the Ship-clock and glancing to his Swiss Chronograph on his wrist … knows !

Joel O'Bryan opts for ethno-religious imagery and says:

April 16, 2014 at 9:29 pm
This analysis is devastating to the “CO2 is evil” CAGW believers.
Ayatollah Al “Jezeera” Gore will issue a Fatwah against this blasphemy any day now.

Bob Greene's intuition is off.  Climate models are geared for long range not short range.  In the short term, random weather fluctuations can dominate. In the long term, these even out.  And like many others, he seems to be held in thrall by the mighty dollar and says:

April 16, 2014 at 9:15 pm
Results of 108-114 models were compared to actual temperatures. The models give a wider spread of results (0.4°C) for shorter time periods (Fig. 1 a and b) and a narrower spread for the longer time period. This seems to be intuitively wrong if the models had any capability to match reality.

Models that don’t work so large numbers are used to create reality. How many wrongs do you have to use to make a right? The ensemble doesn’t do too well at matching reality. It’s total gibberish. How many billion dollars were poured down this rat hole? And they give advanced degrees and nice tenured professorships for this?

norah4you says something about "courses to learn".  It looks as if she could do with some "learning" herself:

April 16, 2014 at 9:59 pm
Had been better had IPCC sent their so called experts on courses to learn by understanding Theories of Science what they forgot to learn during attending same courses once upon a time….

Peter Miller brings up the subject of satellites and says:

April 16, 2014 at 10:40 pm
And let’s not forget our gratitude for the satellites which measure global temperature, for they have kept the statistics reasonably honest for the past 35 years. Prior to the late 1970s, the manipulation/torture/homogenisation of temperature data has run riot, especially the GISS numbers.

Without the satellites acting as the police, the IPCC models would have undoubtedly been shown to be ‘correct’. 

Not a bad note to end on. Let's compare the two satellite records of lower troposphere temperatures (UAH and RSS) with that recorded below on the surface (HadCRUT4 and GISTemp). Click for larger view:

Chip Knappenberger is still trying to shove the Overton Window at WUWT

I first came across the term "Overton Window" when learning about climate science.  The idea is that in a given area of public policy, only a narrow range of policy options will be acceptable and that range is defined by what policy-makers believe they can support and still win re-election.

Climate science deniers keep trying to push the window of policy options to mitigate climate change such that there will be no policy action.  First they wanted to reject climate science altogether, claiming it to be a hoax.  Some of them still do, with conspiracy theories getting wrapped up with older conspiracy theories relating to all sorts of things, often anti-Semitic.  Others used to try to claim that CO2 is plant food as if the fact that some plants respond to CO2 (all other things equal) will outweigh all the downsides of a rapidly warming world.  There are some deniers who don't deny that greenhouse gases exist and that CO2 is one of them, but try to argue that for some reason this time around, greenhouse gases won't behave as they've always done in the past.  From now on, they argue, the warming won't be as great as it was in the past when greenhouse gases increased.

All of the above positions are a rejection of science.  Which is why people who hold these various views are often called "science deniers".  The reasons individuals hold some or all of these views (yes, even contradictory views) are varied, but often are based in their world view.  They cannot reconcile a world view that includes public policy with their own world view of individualism.  These are people who are not comfortable living in harmony with others.

Now there are people who probably understand the science very well who promote disinformation. The reason they do so is to try to push the Overton Window such that it excludes policy options to mitigate climate change. It's their job. It's what they are paid to do.  When the day of reckoning comes they are likely to whine that they were only doing what they were told by their paymasters.

There is an article at WUWT today (archived here) by someone who I suspect is one such person.  He probably understands the science but is trying to position the Overton Window away from policies that promote clean energy.  The person is Paul C. “Chip” Knappenberger.  He often pairs up with Pat Michaels, another science disinformer, and are known here as Pat 'n Chip. It's Chip's job as assistant director of the Center for the Study of Science at the Cato Institute to try to position the Overton Window in a place that suits the people who fund the Cato Institute.

His argument is not logical or coherent or correct.  It is not in accord with the science.  The tack he's taking today is that the AAAS is wrong.  After all, what would this organisation know about science?

The American Association for the Advancement of Science (AAAS) is the world’s largest non-government general science membership organization and the executive publisher of Science, a leading scientific journal.

Put the AAAS against a right wing political lobby group and see how the science stacks up. You can read the AAAS science here.  We can sum up Chip's argument as follows (archived here):

1. CO2 is a greenhouse gas and more of it makes the world heat up more.
2. The world isn't going to heat up as much as most science finds it will because he's found a couple of oddbods who will back him on that assertion - such as a retired financier rather than climate scientists, but what the heck.
3. Action to mitigate global warming is both inapplicable and will be ineffective. [Sou: Point 3 doesn't follow from point 1 or point 2. Chip isn't strong on logic.]

Chip would never get a job in the insurance industry, which is probably why he's stuck writing nonsense for a right wing lobby group.  As Nicholas Stern pointed out on ABC Lateline last night, these are very high risks.

Whatever we're doing we can't reverse.  The best we can hope for is to stop doing it, but we're stuck with the damage we've already done and the future consequences of the damage we've already done.  That means that we have to be damn sure of ourselves in the action we take.

This is a very high risk path we've taken.  The chance of mild warming is much lower than the chance of high warming and all the other consequences such as irreversible damage to ecosystems on land and in the oceans; irreversible melting of ice sheets and glaciers, meaning irreversible sea level rise.  We still have some choice in how quickly these changes happen and the extent of them.  But we've already put the changes in motion.

Chip is making a judgement call that we'll be able to adapt in time to the incredibly rapid changes.  He's not just a risk-taker, he's foolhardy to the point of being certifiably insane, and wants everyone else to play his high stakes game.

From the WUWT comments

The fact that Chip is agreeing that the greenhouse effect and global warming are real means that the Overton Window he's shoving allows a little bit of science to peep through, even though he wants to shut out most of it.  Let's see how the deniers at WUWT react.  There aren't a lot of comments yet. You can read them here.

Robber is an illiteratum and says:

March 27, 2014 at 1:36 pm
Are they the Association for the Advancement of Science or the Association for Shaming & Scuttling Science?

Chad Wozniak is also a member of the illiterati and says:

March 27, 2014 at 1:41 pm
@Robber -
The American Association for the Adulteration of Science.

wws says people are disinterested and dumb, and America is the entire world:

March 27, 2014 at 2:29 pm
And you wanna know what is the PERFECT counter to this, as far as communicating our message to any average voter? “COLDEST WINTER IN 100 YEARS!!!” And that’s all. If they’re really interested, show them the simple chart, and then stop talking. One simple picture destroys years of studies and thousands of words of explanations.

Who cares if it’s not a perfectly accurate representation of the big picture? Not your average voter, that’s for sure.

Pat 'n Chip play with climate models at WUWT

Updated - See below to find out just how wrong Pat'n'Chip are.


Paul C. “Chip” Knappenberger and Patrick J. Michaels are at it again at Anthony Watts' blog WUWT.  I don't think anyone else would have them apart from some right wing rags.

They are claiming that the models are all wrong.  They said they used the model runs as provided on the KNMI Climate Explorer website.  So I went to Climate Explorer and just downloaded the data for RCP8.5 and RCP2.6 and compared it to GISTemp.  This is the result:

Data Source: NASA and Climate Explorer

You'll notice there's little difference between RCP8.5 and RCP2.6.  They don't start to diverge for a few more years.

Bearing in mind there are no error bars shown and that the errors in the observations increase as you go back in time, what strikes me is how darn close the modeled surface temperature is to the observations.

So then I went back to WUWT to see why Pat'nChip say the models are "all wrong".  They wrote:

But very few  people know that the same situation has persisted for 25, going on 35 years, or that over the past 50-60 years (since the middle of the 20th century), the same models expected about 33 percent more warming to have taken place than was observed.

33% more warming since the 1950s? Now that's not what the data shows above.  The observations are fairly closely aligned to the model mean.

---

Update

Here are two more charts.  I've started them at 1951 because Pat'nChip say that "over the past 50-60 years (since the middle of the 20th century)" the models expected 33% more warming.  That's balderdash as you'll see in these charts:

Data Source: NASA and Climate Explorer

Look at the above chart from 1951 to 2001.  The linear trend in the observations is almost indistinguishable from (and slightly steeper than) that of either of the two RCPs.  This completely contradicts the claim of Pat'n'Chip about the "situation has persisted" for last 50-60 years.

Next is 1951 to 2012.

Data Source: NASA and Climate Explorer

Over the period 1951 to the present, the trend for the models is slightly steeper than that of the observations. But certainly not by 33%! It's not even half that. The divergence is from around 2005 onwards.

End Update.

---

So what did Pat 'n Chip do?  They haven't compared the models to the observations directly.  What they did was this:

We’ve calculated the trend in the global average surface temperature simulated to have occurred starting in every year since 1950 and ending in 2012 for every* run of every climate model used in the new IPCC report. In Figure 1, below, we compare the average (and spread) of these 106 model runs with the observed trend during each of the same periods.

They say they calculated the trend in °C/decade, rather than plotting the straight temperature.  I've played with the data a bit but I can't get anything like their chart shown below. (click to enlarge):

I'm guessing they've smoothed the derivatives for starters. However I don't understand how they got such different rates of warming between models and observations.  If you compare it to the result in my first chart, the models and observations correspond well, particularly in the period from around 1930 to around 2004-05.  (The observations show more variation because the model plot isn't a single run, so any variation is averaged out.)

Maybe someone can help me out here and tell me how Pat 'n Chip calculated the rate of warming, and why it appears to be different to what I, at least, would expect.

Curry and Watts - dejected, rejected

The deniers really are running out of stuff to complain about.  Judith Curry is getting nuttier by the day (archived here) and now anti-science blogger Anthony Watts has joined in the fray at WUWT (archived here).

Three out of five GRL papers get rejected

Three years ago a paper got rejected by Geophysical Research Letters.  GRL is quite a prestigious publication and according to a paper in BAMS by David M Schultz, it rejects 59.2% of submissions.  That's not counting author withdrawals or submissions transferred to other journals.  That means that just going by odds, if you submit a paper to GRL it's more likely to be rejected than published.

A motley lot of deniers

The paper purported to be a comparison of climate models with observations.  The authors of the paper are a who's who of deniers - Patrick J. Michaels and Paul C. Knappenberger (Pat 'n Chip), John R. Christy (who tells fibs to US Congress), Chad S. Herman (who I don't know) and Lucia M. Liljegren (a nitpicking blogger who is a science denier of the "lukewarmer" variety).

After the first rejection, this motley lot called in James D. Annan to try to resurrect the paper and package it in way that would be acceptable to the journal.  This didn't succeed either.  I've no idea why James decided to throw in his lot with that lot.  According to Judith Curry he was one of the reviewers for the first draft.  Maybe he thought he could turn it into something useful.  But again according to Judith Curry, the next draft was reviewed by four people, all of whom recommended it not be published.

An excuse for Judith Curry to unfairly wail "not fair"

Judith Curry, who converted to denialism some time ago, has decided to make a big deal out of this, acting as if the journal is 'gatekeeping' against sceptics.  She won't entertain the notion that the paper didn't meet the requirements of GRL, which it obviously didn't.  Although she says she "couldn’t see why it was rejected", she's not a climate modeler nor is she a statistician, so what would she know?  And even if there were "nothing wrong with it" that doesn't automatically mean that GRL would have accepted it.  Journals reject papers for many reasons other than being "wrong".

Anthony Watts has picked up the story too.  (Archived here.)  He's always keen to promote the "gatekeeper" myth that papers get rejected because they are written by fake sceptics rather than because they don't meet the standard or other criteria of the journal.  He's also probably preparing his readers that his own still pending paper won't meet the criteria of any decent journal.

Remember, this all happened three years ago.  James Annan wrote about it on his blog back in May 2010. Why they didn't bother to try another journal is anyone's guess.  Maybe the feedback from reviewers discouraged them from doing so.  Or maybe they just wanted an excuse to cry "gatekeepers".

An excuse for Judith Curry to sing the praises of disinformers

The reason for Judith bringing all this up seems to be so that she can once again sing her praises of disinformation peddlers - David Rose and John Christy.

Judith Curry "came out" as a science denier quite a while ago.  She no longer pretends to be "building bridges".  She's pitched her tent with the disinformers and is now a disinformer in her own right.  Anthony Watts, needless to say, welcomes her with open arms.

If you want to read the paper itself you can do so here to save you having to wade through the nonsense on Curry's blog.  James Annan's blog includes some discussion of the analysis if anyone is interested in the unpublished work.

Just another nutter

I'll leave you with what is probably the denier quote of the day, from Judith Curry this time:

And we see where ‘pause denial’ has led the IPCC, potentially to a crisis point in the AR5.  It will be very interesting to see how this plays out in Stockholm next week.

Crisis point?  Judith Curry really is just another nutter of the David Rose  and Heartland Institute variety.

Approaching crisis point

There is no 'crisis point' yet - although we are rapidly approaching it.  The sooner we act the less it will cost and the greater the likelihood that human civilisation will survive. The latest cost estimate is one per cent of GDP but the cost will rise the longer we leave it.

From the WUWT comments

Just a couple, because they typify WUWT denier weirdness and paranoid conspiracy (archived here):

gopal panicker says:

September 20, 2013 at 10:05 am
cooling started three years ago…have fun

GunnyGene says:

September 20, 2013 at 10:16 am
It was obviously rejected because it doesn’t support the political agenda of global domination by Progressives,etc. You are familiar with Agenda 21, I presume?

Oh, we can all play that game of Pat 'n Chips - the illiterati duo

Pat Michaels and Paul C. “Chip” Knappenberger have written another disinformation blurb for the anti-science blog of Anthony Watts, WUWT.  This time it's about BAMS State of the Climate 2012 report (it must be popular and can be a bit slow downloading.  I have copied some of the highlights here.)

Pat 'n Chip complain that the science is settled

The report is very extensive (239 pp).  (It has eight pages, two-columns each in small type listing all the authors.)  Yet Pat 'n Chip dismiss it as "nothing new here"!  How ignorant does that make them look?  Typical of the bottom 8% dismissive group of illiterati!

(What they are effectively saying/complaining about is that much of the science is settled.)

Pat 'n Chips have become lazy and just put links instead of regurgitating their denialist tripe.  Well, I can play that game too.  I haven't been at this blog nearly as long as Pat 'n Chips have been protesting climate science. But I've a small collection.

• Pat Michaels is full of crap (again)
• Anthony Watts' Next Trick is to Disappear the Data - or Laughing at Pat Michaels
• Recycling Pat 'n Chip disinformation on WUWT brings out denier weirdness
• Making a meal of Pat 'n Chip on WUWT ...or...Don't shoot the messenger

Here are just a few of the many rebuttals of Pat 'n Chip from Tamino:

• Chip’s Cherries
• USA48 - He (Chip of Pat 'n Chips) starts by showing only data through 1997, dropping the hot years which followed, and claiming...
• Best Case Scenario - ...which proves one thing: that Knappenberger doesn’t get it. In more than one way.

Now a few from SkepticalScience:

• Patrick Michaels: Cato's Climate Expert Has History Of Getting It Wrong
• Climate Misinformer: Patrick Michaels
• Patrick Michaels' 1992 claims versus the 2012 reality
• Patrick Michaels: Serial Deleter of Inconvenient Data
• Patrick Michaels Continues to Distort Hansen 1988, Part 1
• Patrick Michaels Continues to Distort Hansen 1988, Part 2

There's lots more documentation of the shenanigans of serial disinformers Pat 'n Chip.  One or other will pop up in all sorts of places.

From the WUWT comments:

noaaprogrammer doesn't know this is a new report prepared by AMS not the NOAA.  Not only that but the poor thing is looking for a conspiracy:

August 7, 2013 at 7:57 pm  Is there a traceable memo from the Whitehouse to NOAA urging or suggesting that they re-issue this “State of the Climate 2012” report? Who might be an investigative reporter that isn’t an AGW believer that could do this?

Village Idiot has pegged Pat 'n Chip and Anthony Watts and writes:

August 7, 2013 at 9:59 pm  Yep, Paddy and Chip. They really should start being a bit more imaginative; make some stuff up – then we could pick them up on it and get some media attention

Recycling Pat 'n Chip disinformation on WUWT brings out denier weirdness

There are a couple of deniers who hang out at Anthony Watts' anti-science blog, WUWT, from time to time.  This pair go by the names of  Paul C. “Chip” Knappenberger and Patrick J. Michaels.  I don't know if they are denialists themselves or not, but they are known for spreading disinformation wherever they can.  They are from the Cato Institute, which is a libertarian think tank/lobbying organisation, initially set up by "coal" Koch, that promotes denial of climate science.

This time they have recycled an article from the Economist and are putting a lot of weight on climate sensitivity studies (Bayesian approaches) that tend to the lower end of the suite of projections.  Pat 'n Chip are writing as if all studies are showing lower climate sensitivity, which is not so.

First up, I'll point out as have others, that the Economist article was based on something it says is in the working group on mitigation, not on the physical sciences.  So it means zilch.

Secondly, climate sensitivity is important to know, but it doesn't have to be known precisely.  What is more important to my mind is behaviour.  If we double or treble the amount of atmospheric CO2 or worse, we'll definitely turn up the heat to more than we can handle.

I did a quick search of Google Scholar for climate sensitivity studies in the past couple of years.  There are swags of them.  The only ones that Pat 'n Chip want their readers to know about are the ones that come in at the lower end of the spectrum.  But there are many recent studies that come up with the same sort of numbers that the IPCC came up with in the past.  It's just that the media hasn't picked up on them.  Probably because they are the norm rather than the exception.

Here's a sample from the first few studies that come up in a Google Scholar search:

• Equilibrium = 3.2˚C; transient 1.72˚C

Bitz et al (2012) Climate Sensitivity of the Community Climate System Model, Version 4, J Climate DOI: 10.1175/JCLI-D-11-00290.1

• Equilibrium = 2.2 - 4.8˚K

Rohling et al (2012) Making sense of palaeoclimate sensitivity, Nature DOI: 10.1038/nature11574  (Thanks to BBD for the link to the full paper).

• Equilibrium = 2.1 - 4.7˚K

Andrews et al (2012) Forcing, feedbacks and climate sensitivity in CMIP5 coupled atmosphere-ocean climate models, GRL

• Equilibrium = 1.9˚C (1.2 to 2.9˚C); transient = Using observational data up to and including year 2010 gives a 90% C.I. of 1.0 to 2.1˚C, while the 90% C.I. is significantly broader ranging from 1.1 to 3.4 ˚C if only data up to and including year 2000 is used.

Skeie et al A lower and more constrained estimate of climate sensitivity using updated observations and detailed radiative forcing time series, Geophysical Research Abstracts


Pat 'n Chip would have the scientists exclude all the higher estimates and only publish the lower estimates.  Many if not most of the lower estimates seem to come from Bayesian analysis, while the higher ones more commonly come from analysis of past climates (paleoclimatology) or climate models - which are based on physics.

The reason seems to be that they want permission to continue to pollute the atmosphere for a while longer yet.  Obviously they don't give tuppence for what happens to humanity, society or any other life on earth in the future.  Otherwise they'd be arguing that regardless of whether equilibrium sensitivity was 2˚C (which Pat 'n Chip favour) or 3˚C or 4˚C or higher, if we don't stop burning fossil fuels soon climate change will get much worse.

Thing is, equilibrium sensitivity won't mean zilch if we don't stop at doubling CO2.  No-one will be any the wiser about what it would have been.  Humans will have to wait until equilibrium does occur for however many multiples of CO2 we pour into the air, which will take thousands of years as illustrated here. (Click to enlarge.)

Source: RealClimate.Org

From the WUWT comments

I was curious to see how the deniers at WUWT would react.  After all, Pat 'n Chip are arguing that climate sensitivity is 2˚C.  Many deniers at WUWT think CO2 doesn't have any effect on surface temperature.  Some even think that we are about to enter an ice age - any day now - and have thought that for quite some time.  (They are very patient.)

Pseudo-science gobbledegook from Konrad

The response was a mixed lot with people mostly talking past each other.  Here is some classic pseudo-science from Konrad, who says pre-industrial CO2 is fictitious, that "LWIR" (does he think there is such a thing as SWIR I wonder?) doesn't affect the cooling rate of water that is free to evaporatively cool - presumably evaporating because of cooling?  And radiative gases cool the earth, not heat it!

July 26, 2013 at 5:32 pm  “Climate sensitivity” to a doubling from fictitious “pre-industrial” levels would be around -0.00000001 C. To arrive at this figure you of course have to ignore all the evidence that temperature drives atmospheric CO2 concentration at all time scales. Next reduce those ludicrous figures for DWLWIR slowing the cooling of the earths surface by 71percent. LWIR doesn’t effect the cooling rate of water that is free to evaporativly cool.
Now as the troposperic lapse rate created by convective circulation is near the adiabatic limit, there is little need for ajustment here. However speed of convective circulation and mechanical energy transport from the surface should be increased for higher radiative gas concentrations.
The ERL argument can be safely ignored as it is junk science. In a moving atmosphere, warm air masses are transporting energy high above the level of maximum IR opacity, where they always radiate more than the air at the altitude they are rising through.  You should find that radiative gases act to cool the atmosphere at all concentrations above 0.0ppm.  The IPCC however should continue to do static atmosphere calculations and assume surface IR absorption based on emissivity. Otherwise they won’t get paid.

Asian aerosols caused global warming and incomprehensible quackery from AlecM

This one is a new one for me.  AGW was caused by aerosols!  (Most aerosols reflect sunlight and have a cooling influence.)  This from AlecM:

July 26, 2013 at 11:39 pm My view is that the atmospheric control system that damps out natural fluctuations is near 0 K CO2 climate sensitivity. There has been AGW, from Asian aerosols reducing the albedo of low level clouds. This led to the 1980s and 1990s heating but has now saturated. It lead to the ocean temperature rise What we are seeing now in the reduction of TPW and the turn down of OHC and air temperature is the effect of operation of other parts of the control system. CO2 is automatically eliminated from the temperature effects.

The Other-Andy hasn't looked at a temperature chart since 1979

From where on earth does the Other_Andy get his information?

July 27, 2013 at 3:05 am  So, according to the warmists CO2 (And positive feedbacks) controls the Earth’s temperature. As CO2 goes up so does the temperature.
Between 1979 and 1996, CO2 increases by 25 ppm (More than 7% increase), there are several El Ninos and the temperature stays the same. What is their explanation?

The Other_Andy's close enough with the CO2 increase, but he says temperature stayed the same between 1979 and 1996?  Not so:

Data Sources: NASA and UK Met Office Hadley Centre

Making a meal of Pat 'n Chip on WUWT ...or...Don't shoot the messenger

Anthony Watts and Patrick J. Michaels had a miss on WUWT yesterday, so they are trying again.  This time with the help from Paul C. “Chip” Knappenberger.  Once again it's tactic of appealing to the fear factor that by all accounts is one of the main causes of disability of science deniers.

By way of introduction, research suggests that the fear factor prevents some people from rational thought. There is a strong association between this impediment and conservatism.  Fear causes cognitive dissonance which is only allayed by allaying the fear.  That becomes the priority.  When threatening facts can't be refuted then anyone who misrepresents the facts and lowers the fear becomes the new messiah.  It doesn't matter how wrong they are.  The fact they've reduced the fear is sufficient for the professional disinformer to be hailed as a hero.

Strike One: Unveiling The Strawman

First the build up.  Pat and Chip lead in with this, referring to Dr James E Hansen:

Specifically, he believes global average sea level will rise some 15 to 20 feet by 2095.

The question is, does Dr Hansen really believe this as a foregone conclusion?  Pat and Chip refer their readers to this book chapter by Hansen and Sato¹.  Even a cursory read shows that the authors are not at all categorical.  What the authors maintain can be read in the abstract (my bold):

Gravity satellite data, although too brief to be conclusive, are consistent with a doubling time of 10 years or less, implying the possibility of multi-meter sea level rise this century

He believes vs implying the possibility of.  What Pat and Chip have carelessly done is build a strawman.

That's easy to do for the WUWT crowd who thrive on their disdain of climate science and especially of climate scientists and most especially of three or four climate scientists in particular.  James Hansen and Michael Mann are at the top of their list.  But the strawman really wasn't necessary.

Indeed the entire article wasn't necessary.  One word would have sufficed.

Pat and Chip - all you have to do is write the single word "Hansen" and the deniers go rigid with rage, their faces twisted into a slathering snarl, the words on the screen melt together in a blur and their hands are clenched so tightly they can barely unbend their fingers to type in the WUWT comment box.  The relief after clicking "Post Comment" is profound, and surges through their body. They take a deep breath and wait avidly for someone, anyone to acknowledge their intense feelings expressed variously as - "only in it for the money", "activist", "gravy train", "CAGW", "hoax" and "scam". (Yes, a bit of a let-down, isn't it :))

Don't believe me?  I wrote the above in advance of any responses to the article - now go check the comments.

Strike Two: Geography Fail

After that little diversion, back to what Pat and Chip did.  The straw man is built, now they try to knock it down.   I won't bore you with details of "another scientist said something therefore Hansen is wrong about everything", which is the basis of their argument.  I will point out that they are not crash hot at geography or logic.  Here is how I know.  Pat and Chip quote this passage from the Hansen and Sato chapter (with a couple of words changes for some reason):

However, the primary flaw with the kinematic constraint concept is the geology of Antarctica, where large portions of the ice sheet are buttressed by ice shelves that will not survive BAU climate scenarios. West Antarctica's Pine Island Glacier (PIG) illustrates nonlinear processes coming into play. The floating ice shelf at PIG's terminus has been thinning in the past two decades as the ocean around Antarctica warms Shepherd et al., 2004). Thus the grounding line of the glacier has moved inland by 30 km into deeper water, allowing potentially unstable ice sheet retreat. PIG's rate of mass loss has accelerated almost continuously for the past decade (Wingham et al., 2009) and may account for about half of the mass loss of the West Antarctic ice sheet, which is of the order of 100 km3 per year(Sasgen et al., 2010).

Okay.  This paragraph follows from a discussion of Greenland.  Hansen and Sato are pointing out that West Antarctica is very different to Greenland.  (These are the two locations of greatest concern in the near future in regard to near term sea level rises.  That is, of the order of decades to centuries.)

Pat and Chip write the silliest thing.  They say:

While West Antarctica may be losing ice mass, East Antarctica appears to be gaining, as higher sea surface temperatures lead to more moisture in the atmosphere which leads to greater snowfall there.

Even if they were correct about East Antarctica gaining some, what the heck has snowfall in East Antarctica to do with the potential risks of glaciers melting in West Antarctica?  That's like saying people in San Fransisco don't need to be concerned about earthquakes because there's not much risk of a major earthquake in Boston.  Look for yourself.  Note the scale at the bottom and the mountain range separating east from west. (Click to enlarge):

Source: NASA via Wikipedia

If Pat and Chip make such a big deal about the Pine Island Glacier not being a problem because it's pretty darn cold in the middle of the high mountains in East Antarctica, then what else are they so wrong about?

Strike Three: And They are Out

Next Pat and Chip try to tell you that sea levels weren't higher in the Pliocene after all.  Their evidence?  This is what they write (by the way, prefaced with an "oops" -  implying that Hansen and Sato should have read a paper published just two weeks ago, before writing their chapter two years ago):

Oops. Wrong again. Breaking scientific research just published online from the journal Science (Rowley et al., 2013) conclude that the apparent 25 ± 10 meter sea level rise during the Pliocene was probably due to vertical land motions during the intervening 3 million years rather than an actual sea level rise from more water in the oceans from melting ice (Hansen’s mechanism).

Is that what the paper actually said?  By all accounts, no.  You can read the abstract here in Science Express, and the full article if you're a subscriber.  The abstract doesn't say that sea level rise wasn't as high as thought, it says that you can't determine the sea level from that stretch of land because it shifted as a result of mantle flow.  In other words, what is thought of as a "passive" shoreline was subject to movement.  Let's see what the press release has to say:

"The highlight is that mantle flow is a major component in distorting the Earth's surface over geologic time, even in so-called 'passive' continental margins," Simmons said. "Reconstructing long-term global sea-level change based on stratigraphic relations must account for this effect. In other words, did the water level change or did the ground move? This could have implications on understanding very long-term climate change."

This work may change estimates of sea level in the Pliocene or it may not.  It depends on what other evidence suggests.  But it seems to me that it doesn't necessarily negate higher sea levels.  Nor does it tell us about sea levels in other eras when the earth was as warm as we're heading towards.  I would have a lot less certainty than Pat and Chip that sea level rise will be benign - and I live 200 km from the coastline.

Where does that leave us?

What Hansen is concerned about is that people will allow themselves to be lulled into a false sense of security, thinking that sea levels will rise only gradually and by 'only' a half metre or so this century.  But glaciers in particular are slippery things - they can slide into the ocean, huge chunks can break off and there could be a sudden larger rise.  Heck, imagine if instead of a twenty cm rise in a century there was a half meter rise in a decade.  Imagine a storm surge or a cyclone.  It's not going to be much comfort to inhabitants of coastal cities to say, sorry - we knew it was possible but we didn't think it was likely so we kept on burning fossil fuels.

Maybe the seas won't rise two meters this century.  Maybe it won't happen for another 120 years.  That would foist the problem onto our children's children.  What will they think of us, knowing we could have prevented a sudden rise?

And what will half a meter rise in sea level mean?  We might have only a few decades to relocate thousands of cities and billions of people to higher ground.  That's an enormous undertaking.  (Think of large infrastructure projects that can take anything from ten years to thirty years to completion.)

Here are the closing paragraphs from Hansen and Sato.  Their projections are on the high side for the Business as Usual scenario.  Does that mean we should ignore them in favour of projections that are less uncomfortable just because we prefer the latter?  Surely that would be another logical fallacy - that of personal incredulity. (My bold and italics for emphasis.)

BAU scenarios result in global warming of the order of 3-6°C. It is this scenario for which we assert that multi-meter sea level rise on the century time scale are not only possible, but almost dead certain. Such a huge rapidly increasing climate forcing dwarfs anything in the peleoclimate record. Antarctic ice shelves would disappear and the lower reaches of the Antarctic ice sheets would experience summer melt comparable to that on Greenland today.

The other extreme scenario, FFPO, does not eliminate the possibility of multi-meter sea level rise, but it leaves the time scale for ice sheet disintegration very uncertain, possibly very long. If the time scale is several centuries, then it may be possible to avoid large sea level rise by decreasing emissions fast enough to cause atmospheric greenhouse gases to decline in amount.

What about the intermediate scenario, EU2C? We have presented evidence in this paper that prior interglacial periods were less than 1°C warmer than the Holocene maximum. If we are correct in that conclusion, the EU2C scenario implies a sea level rise of many meters. It is difficult to predict a time scale for the sea level rise, but it would be dangerous and foolish to take such a global warming scenario as a goal.

The upshot is that sooner or later ice is going to melt and seas will rise.  That is certain.  The question is over what time scale.  How long do we have and will it be sudden or gradual.  Will there be sudden shifts over a few years.  Do we want to take the risk?  How lucky do you feel?  How lucky will your grandchildren be?

Whatever we do, we can't shoot the messenger.  Their message might be the most important one we'll ever get.


1. Hansen, J.E., and Mki. Sato, 2011: Paleoclimate implications for human-made climate change. In Climate Change: Inferences from Paleoclimate and Regional Aspects. A. Berger, F. Mesinger, and D. Šijači, Eds. Springer.