New Climate Science Update: Latest Findings Since 2006 Report

[Xnn]

Science marches on.

The http://www.ipcc.ch/publications_and_data/publications_ipcc_fourth_assessment_report_wg1_report_the_physical_science_basis.htm" for climate change was based on
peer reviewed literature available in 2006. Since that time,
there have been a number of newer studies that have contributed
to a better understanding. These have been put together into a
http://www.ccrc.unsw.edu.au/Copenhagen/Copenhagen_Diagnosis_LOW.pdf" for the meeting in Copenhagen.

In general, uncertainties resolved since 2006 point to a more
rapidly changing and more sensitive climate than previously thought.
There are several interesting sections in the report with lots of vivid
color photos. However, overall it is a sombering report.
CO2 emissions are accelerating while temperatures, sea level and
water cycle increases are all expected to accelerate.
It's very difficult to conceive the climate tracking anything but
the upper end of the projections.

Here are highlights from the new report:

Global carbon dioxide (CO2) emissions from fossil fuel burning in 2008 were 40%
higher than those in 1990, with a three-fold acceleration over the past 18 years.

Global CO2 emissions from fossil fuel burning are tracking near the highest scenarios
considered so far by the IPCC.

The fraction of CO2 emissions absorbed by the land and ocean CO2 reservoirs has likely
decreased by ~5% (from 60 to 55%) in the past 50 years, though interannual variability is
large.

Global air temperature, humidity and rainfall trend patterns exhibit a distinct fingerprint
that cannot be explained by phenomena apart from increased atmospheric greenhouse gas
concentrations.

Every year this century (2001-2008) has been among the top 10 warmest years since
instrumental records began, despite solar irradiance being relatively weak over the past few
years.

Global atmospheric temperatures maintain a strong warming trend since the 1970s
(~0.6°C), consistent with expectations of greenhouse induced warming.

Increases in hot extremes and decreases in cold extremes have continued and are expected
to amplify further.

Ice-shelves connect continental ice-sheets to the ocean. Destabilization of ice-shelves
along the Antarctic Peninsula has been widespread with 7 collapses over the past 20 years.

Signs of ice shelf weakening have been observed elsewhere than in the Antarctic Peninsula,
e.g. in the Bellingshausen and Amundsen seas, indicating a more widespread influence of
atmospheric and oceanic warming than previously thought.

There is a strong influence of ocean warming on ice sheet stability and mass balance via the
melting of ice-shelves. Anthropogenic climate change is expected to lead to further increases
in precipitation extremes, both increases in heavy precipitation and increases in drought.

Although future changes in tropical cyclone activity cannot yet be modeled, new analyses
of observational data confirm that the intensity of tropical cyclones has increased in the
past three decades in line with rising tropical ocean temperatures.

There is widespread evidence of increased melting of glaciers and ice-caps since the mid
1990s.

The contribution of glaciers and ice-caps to global sea-level has increased from 0.8
millimeters per year in the 1990s to be 1.2 millimeters per year today.

The adjustment of glaciers and ice caps to present climate alone is expected to raise sea
level by ~18 centimeters. Under warming conditions they may contribute as much as ~55
centimeters by 2100

The surface area of the Greenland ice sheet which experiences summer melt has increased
by 30% since 1979, consistent with warming air temperatures. Melt covered 50% of the ice
sheet during the record season in 2007.

The net loss of ice from the Greenland ice sheet has accelerated since the mid-1990s and is
now contributing as much as 0.7 millimeters per year to sea level rise due to both increased
melting and accelerated ice flow.

Antarctica is also losing ice mass at an increasing rate, mostly from the West Antarctic ice
sheet due to increased ice flow. Antarctica is currently contributing to sea level rise at a
rate nearly equal to Greenland.

The observed summer-time melting of Arctic sea-ice has far exceeded the worst-case
projections from climate models of IPCC AR4.

The warming commitment associated with existing atmospheric greenhouse gas levels means
it is very likely that in the coming decades the summer Arctic Ocean will become ice-free,
although the precise timing of this remains uncertain.

Satellite observations show a small increase of Antarctic sea-ice extent and changes to
seasonality, although there is considerable regional variability. This is most likely due to
changes in Southern Ocean winds associated with stratospheric ozone-depletion.

Estimates of ocean heat uptake have converged and are found to be 50% higher than
previous calculations.

Global ocean surface temperature reached the warmest ever recorded for each of June, July
and August 2009.

Ocean acidification and ocean de-oxygenation have been identified as potentially
devastating for large parts of the marine ecosystem.

Satellite measurements show sea-level is rising at 3.4 millimeters per year since these
records began in 1993. This is 80% faster than the best estimate of the IPCC Third
Assessment Report for the same time period.

Accounting for ice-sheet mass loss, sea-level rise until 2100 is likely to be at least twice as
large as that presented by IPCC AR4, with an upper limit of ~2m based on new ice-sheet
understanding.

There are several elements in the climate system that could pass a tipping point this century
due to human activities, leading to abrupt and/or irreversible change.

1 °C global warming (above 1980-1999) carries moderately significant risks of passing large
scale tipping points, and 3 °C global warming would give substantial or severe risks.

There are prospects for early warning of approaching tipping points, but if we wait until a
transition begins to be observed, in some cases it would be unstoppable.

The full report is available here:

http://www.copenhagendiagnosis.com/default.html

Link directly to pdf file:

http://www.ccrc.unsw.edu.au/Copenhagen/Copenhagen_Diagnosis_LOW.pdf

 

[vanesch]

I have to say I hate this kind of semi-scientific-political publi-brochure. This kind of stuff is exactly what makes people wary of climate science. This looks like an advertisement !
That doesn't mean that what's said in there is wrong, but I don't like the commercial way in which it is said.


Just some things on the surface that shock me:
From the first grey box, in fact the very first sentence of the report:

Global carbon dioxide (CO2) emissions from fossil fuel burning in 2008 were 40% higher
than those in 1990, with a three-fold acceleration over the past 18 years.

There is also:

CO2 levels increased at a rate of 1.9 ppm/year between
2000 and 2008, compared to 1.5 ppm/yr in the 1990s.

Now how does that rime with figure 2, where we see an almost linear rise of CO2 in the atmosphere since 1980 ?

It seems to me that especially alarming language is used here, as if one had to promote a certain product.

 

[Sorry!]

I have to say I hate this kind of semi-scientific-political publi-brochure. This kind of stuff is exactly what makes people wary of climate science. This looks like an advertisement !
That doesn't mean that what's said in there is wrong, but I don't like the commercial way in which it is said.Just some things on the surface that shock me:
From the first grey box, in fact the very first sentence of the report:There is also: Now how does that rime with figure 2, where we see an almost linear rise of CO2 in the atmosphere since 1980 ?

It seems to me that especially alarming language is used here, as if one had to promote a certain product.

It is kinda of a weird way of them to promote their findings though (in a brochure) but we have to think about who this is trying to sway... the common person. This isn't really meant for scientists to use it's meant to be a political tool (which I admit isn't the best thing but nearly all science has political aspects, climate change just has more due to its seeming importance to the world)

 

[sylas]

I have to say I hate this kind of semi-scientific-political publi-brochure. This kind of stuff is exactly what makes people wary of climate science. This looks like an advertisement !
That doesn't mean that what's said in there is wrong, but I don't like the commercial way in which it is said.

My reaction is completely the reverse. The problem with this whole area is that there is a lot of public interest and a lot of confusion.

If we were serious about simply following the scientific literature, then it would be pretty straight forward and you'd get conclusions pretty much like what is in this report.

However, the scientific literature is written primarily for a different audience. And although the science should be pursued independent of any policy considerations; the reverse is not the case; policy needs to take into account the best available scientific information on matters of relevance.

It follows that there is a need for scientists to communicate better, to a wider audience; not just the general public but governments and other policy makers. The IPCC reports are driven by this requirement.

The interaction between science and politics and policy, in any ideal world, should be like the following:

• The conclusions reached by science need to be obtained without any deference to policy implications of the conclusions. Science ideally seeks answers and confidence limits on those answers based exclusively on what the evidence and research actually can show.
• The questions and issues addressed by scientists, however, might well be driven by secondary requirements of what is deemed important to know, for policy reasons.

Precisely how we improve the communication of credible science is a good question; but anything you do along those lines should be in the way of providing accessible information.

I think this only looks like an advertisement because there is such a gaping disconnect between what is happening in the world of science and what is being debated in the political world. There are a heap of open questions in climate science and all kinds of large uncertainties. But they are not the same as the major uncertainties debated more widely.

The wider questions seem to be things like... is global warming real? is it caused by human activities?

The answers to those two questions are actually very straightforward. It's yes, and yes.

There are riders you can add, along the lines that everything in science is always in principle open to dispute and revision; but for an overview, the "yes" in both cases is about as strong as you can possibly get. The warming is measured. The importance of greenhouse effects is basic physics. And the association of that to human activities is unambiguous.

These answers don't rule out all other factors; but the strong warming trend of the latter half of the twentieth century in particular is solidly linked to atmospheric composition and a stronger greenhouse effect.

The relevant open scientific questions are about quantifying the warming trend, along with other effects, refining physical understanding to model it better (a never ending project of continual improvements) and sorting out things like the carbon cycle, the energy balance into the ocean, the feedbacks from cloud and weather and much else beside which bear upon the complex response of the climate system.

Just some things on the surface that shock me:
From the first grey box, in fact the very first sentence of the report:

Global carbon dioxide (CO2) emissions from fossil fuel burning in 2008 were 40% higher than those in 1990, with a three-fold acceleration over the past 18 years.​

There is also:

CO2 levels increased at a rate of 1.9 ppm/year between 2000 and 2008, compared to 1.5 ppm/yr in the 1990s.​

Now how does that rime with figure 2, where we see an almost linear rise of CO2 in the atmosphere since 1980 ?

It seems to me that especially alarming language is used here, as if one had to promote a certain product.

I don't understand your objection here, frankly. The context of this report is a world that is looking at managing carbon emissions as a matter of policy to mitigate against the risks associated with larger changes in the atmospheric greenhouse effect. The report is promoting the need for managing emissions and noting that they are continuing to increase at levels that are right along the high end of the range of projections considered in the most recent IPCC report.

Figure 2 is completely consistent with the numbers given. The rate of increase IS increasing and you can see quite easily that the increase since 1980 is not linear. Just hold a ruler up against the graph if you want to check. Of course, the proper measure of linearity works from the numbers, not eyeballing a graph, and the numbers are as you have quoted from the report. What’s the problem?

There are a number of other sources that are attempting to address the gap between what is published in the literature and what is accessible to policy matters or interested members of the public. Not all of them are thoroughly grounded in the scientific literature or well reviewed by directly relevant scientific researchers. This one is, however; and stands as a good summary of technical material, thoroughly grounded in scientific literature, produced by a large group of some of the most active scientists researching on the directly relevant science, and with a high level of oversight and review. I think it stands as a useful resource for helping follow this whole topic.

Cheers -- sylas

 

[sylas]

A better link

By the way... the home page for this report

The Copenhagen Diagnosis​

gives easy access to the full report at two resolution levels, an online version, background on the authors, background on the reasons for the report, and so on; which may help understand some of the background to why and how it was written.

 

[Xnn]

From the report:

Global carbon dioxide (CO2) emissions from fossil fuel burning in 2008 were 40%
higher than those in 1990, with a three-fold acceleration over the past 18 years.

Global CO2 emissions from fossil fuel burning are tracking near the highest scenarios
considered so far by the IPCC.

Now how does that rime with figure 2, where we see an almost linear rise of CO2 in the atmosphere since 1980 ?

It seems to me that especially alarming language is used here, as if one had to promote a certain product.

I agree that there is some alarming language in the report. However, the prospects
of significant reductions in emissions are fairly low. As the report points out, emissions
have only increased and I sense that the Climate Scientist that put the
report together are very concerned and frustrated. It's apparent that there
will be a significant climate shift over the next century.

Anyhow, I also struggle with reconciling the 3 fold acceleration in emissions
since 1990 while atmospheric CO2 concentrations have increased steadily
with only the slightest hint of an acceleration.

From the report:

The global rate of increase of fossil fuel CO2 emissions has accelerated
three-fold over the last 18 years, increasing from 1.0% per year in the 1990s to
3.4% per year between 2000-2008 (Figure 1). The accelerated growth in fossil
fuel CO2 emissions since 2000 was primarily caused by fast growth rates in developing
countries (particularly China) in part due to increased international trade of goods
(Peters and Hertwich 2008), and by the slowdown of previous improvements in the CO2
intensity of the global economy (Raupach et al. 2007). The observed acceleration in fossil fuel CO2 emissions is tracking high-end emissions scenarios used by IPCC AR4 (Nakicenovic et al. 2000).

The report does reviews CO2 sinks, but jumps rather abruptly to vulnerabilities.
What's obvious to me is that the sinks have increased almost as fast as emission
have grown. That is rather odd. Sinks ought to be operating in proportion to
atmospheric CO2 concentration, precipitation and winds.

There are 3 major sinks: Plants & soils, the deep ocean and sediments (rocks).
About 30% of CO2 emissions end up in plants and soils, 25% goes into the deep
ocean and <1% ends up in sediments.

The report makes the following statement concerning the deep oceans:

In the Southern Ocean, the CO2 sink has not increased since 1981
in spite of the large increase in atmospheric CO2 (Le Quéré et al. 2007;
Metzl 2009; Takahashi et al. 2009). The Southern Ocean trends have been
attributed to an increase in winds, itself a likely consequence of
ozone depletion (Lovenduski et al. 2008). Similarly, in the North
Atlantic, the CO2 sink decreased by ~50% since 1990 (Schuster
et al. 2009), though part of the decrease has been associated
with natural variability (Thomas et al. 2008).

So, I can only infer that plants and soils have been taking most all
of the slack; in other words there is some good news that may
have been overlooked.

 

[sylas]

Anyhow, I also struggle with reconciling the 3 fold acceleration in emissions
since 1990 while atmospheric CO2 concentrations have increased steadily
with only the slightest hint of an acceleration.

On the contrary. The rate of atmospheric CO₂ increase has accelerated as emissions have accelerated. Remember to to look at the percentage change in the rate of increase; not merely the increase itself.

The major CO₂ observatory is the NOAA monitoring station at Mauna Luo. It provides ready access to most recent measurements and rates of change, both for the Mauna Luo site itself and a global estimate.

The rate of increase varies from year to year; as short term variations that arise from any changes in the global carbon cycle. Over all there is a significant increasing trend in the rate of increase, and a 10 year moving average (for example) shows the rate increasing from around 1.5 ppm/yr to around 1.9 ppm/yr as described in the report. This is a more than a slight hint of acceleration. It is about 27%, though with limited precision.

The data for emissions is cited to Le Quéré et al. (2009) which is listed as in press, though it has just now come out as advance online publication. See

• Corinne Le Quéré et al (2009) Trends in the sources and sinks of carbon dioxide, Nature Geoscience, Published online: 17 November 2009 | doi:10.1038/ngeo689
  Preprint available http://www.civicgovernance.ca/files/uploads/Global_CO2_per_capita_report.pdf[/URL].[/list]
  This has been on my to-do list to write about, as it is particularly relevant to another recent thread on carbon cycles.
  
  This paper notes in the abstract that "fossil fuel emissions increased by 29% between 2000 and 2008", and the text notes an increase of 41% since 1990, as given in the report discussed in this thread. The supplementary information of the paper points us to [url=http://www.globalcarbonproject.org]globalcarbonproject[/url] for the emissions data; also tabulated [url=http://lgmacweb.env.uea.ac.uk/lequere/co2/carbon_budget.htm]here[/url].
  
  1990 was 6.14 Pg emissions; 2008 was 8.67. The uncertainties are around 6%. This is the 41% increase.
  
  There link from emissions to increasing atmospheric levels is surprising complex; but to a first approximation about 40% of emissions remain in the atmosphere.
  
  In any case, the increase in atmospheric CO[sub]2[/sub] is from about 1.5 ppm/yr to 1.9 ppm/yr: around 27%, but with a substantially larger uncertainty given the natural variations on top of the trend.
  
  This is not a discrepancy; we are measuring two different things, which are strongly related, but should not be expected to simply have the same value.
  
  Cheers -- sylas
  
  PS. Xnn, you'd be interested in Le Quéré et al (2009). It is looking at all those details of sources and sinks in the carbon cycle.

 

[mheslep]

1990 was 6.14 Pg emissions; 2008 was 8.67. The uncertainties are around 6%. This is the 41% increase.

There link from emissions to increasing atmospheric levels is surprising complex; but to a first approximation about 40% of emissions remain in the atmosphere.

In any case, the increase in atmospheric CO₂ is from about 1.5 ppm/yr to 1.9 ppm/yr: around 27%, but with a substantially larger uncertainty given the natural variations on top of the trend.

This is not a discrepancy; we are measuring two different things, which are strongly related, but should not be expected to simply have the same value...

I wonder where the balance of the CO2 emissions go - some to the oceans but surely not all?

 

[sylas]

I wonder where the balance of the CO2 emissions go - some to the oceans but surely not all?

Some goes to terrestrial carbon sinks. It all has to go somewhere, and "land/ocean/atmosphere" is a simple classification of the many sinks involved.

Within this broad classification there are all kinds of sinks and many unknowns. The ocean is a number of different regional oceans, which are not uniform, and involves exchanges over all depths, which are not clear. The land sinks are especially hard to figure out. Generally speaking the fraction of carbon that is taken up into the terrestrial sinks is estimated by seeing what is left over after the atmosphere and oceans are considered. There are attempts to further identify where the various terrestrial sinks can be found; but there's no complete accounting and no way to get a direct measurement of all the land sinks. Some wag once described this as the "missing sink", which now makes a good search term to get started finding relevant research.

The "airborne fraction" is the best known; it is around 40% to 45%. That leaves 55% to 60% for other sinks. Page 12 of this report gives a quick summary. The paper by Le Quéré that I have cited is an important contribution and there is a lot more research on this if you want to keep hunting. From Le Quéré (2009):

Combined evidence from atmosphere and ocean observations constrains the mean uptake rates of land and ocean CO₂ sinks to 2.6±0.7 and 2.2±0.4 Pg C yr⁻¹ for 1990–2000, respectively^11,19–22.​

The emissions amount includes both direct industrial emissions (which is what has increased by 41% since 1990) and also emissions from land use change, especially deforestation. Put together As noted previously direct emissions in 2008 were 8.67 Pg. To this we add about 1.2 Pg from land use change (an estimate from Le Quéré 2009) for 2008, giving 9.9 Pg total in 2008.

The atmospheric increase was 1.66 ppm in 2008, which you can simply multiply by 2.13 to get the atmospheric uptake of 3.54 Pg. This varies a lot from year to year, over recent years 1.9 ppm/yr is about the current rate; pretty close to 4 Pg.

Further breaking it all down is an ongoing open question; sorting out how all carbon cycle will continue to work as it keeps being loaded with carbon is also a major open question and significant uncertainty. The "airborne fraction" is about 43%, and most research indicates this is increasing. This is described in the Copenhagen Diagnosis; and more detail is in Le Quéré (2009).

On average, 43% of the total CO2 emissions each year between 1959 and 2008 remained in the atmosphere, but this fraction is subject to very large year-to-year variability (Fig. 2a). This ‘airborne fraction’ increased on average by 0.3±0.2% yr⁻¹ between 1959 and 2008. There is a 90% probability that this increasing trend is significant taking into account the background variability (Methods). The trend and its significance are sensitive to estimates of LUC emissions, which have large uncertainties.​

It seems likely that the trend of an increasing airborne fraction will continue.

 

[Xnn]

Sylas;

Thanks for the link to the Le Quéré paper. I see that she notes the problems
of quantifying sinks and also explains how economic data is used to measure
emissions along with a host of other estimates. So, there is considerable
uncertainty with all of this.

Her charts show both land and ocean sinks trending more negative,
although in 2008 there was a small up tick in ocean sinks due to La Niña
and the southern annular mode:

During La Niña conditions, the land CO2 sink is enhanced owing to lower
temperatures and wetter conditions in the tropics, whereas the ocean
CO2 sink is reduced owing to more intense equatorial upwelling of carbon-rich
waters. Observations in the equatorial Pacific Ocean corroborate the lower ocean
CO2 sink in 2008 (ref. 23) estimated by the models. The ocean models also
attributed the low ocean CO2 sink in 2008 in part to a weaker Southern Ocean
sink, in response to the continuing increase in the southern annular mode.

Anyhow, it's curious that the sinks are trending towards more negative values
and I wonder if maybe perhaps the GDP method of estimating emissions is biased
as the residual chart (figure 2 e) appears to generally be accumulating.

 

[Naty1]

Sylas posted:

The wider questions seem to be things like... is global warming real? is it caused by human activities?
The answers to those two questions are actually very straightforward. It's yes, and yes.

Nice try; but such speculation is political in nature not scientific...38,000 scientists (who signed correspondence to the UN) and others who wrote the US congress strongly disagree about man made causes of climate change.

Even in Australia, home of the uopdated report referenced by Silas, government there remains in turmoil over man made global warming and carbon reduction plans. The Australian senate appears likely to reject such legislation for plans passed by their house.

The legitimate answers to those two questions is ACTUALLY dependent on valid data, valid scientific theory, and models that work...NOT what East Anglica "scientists" concocked/invented/created fraudulently for the IPCC.

The Earth IS likely warming, just like it has thousands of times in the past...but the Earth has emerged from numerous ice ages, some when the Earth was virtually covered in mile thick ice...and it will most likely cool as well in the future, also repeating past changes long before man was here.

One recent recent study shows that infrared radiation from a cabon thick(er) atmosphere actually increases, not decreases, as climate models would have you believe. So there is much left to learn before we declare "victory" in our understanding of climate...besides, whose to say that a warmer climate would not be a big net plus? The Vikings, who tried to settle Greenland when it was previously warm enough to be productive for farming, would likely have argued HOORAY for some warming...

 

[sylas]

Thanks for the link to the Le Quéré paper. I see that he notes the problems...

That's "she", for what it is worth. http://lgmacweb.env.uea.ac.uk/lequere/ is Professor of Environmental Sciences at the University of East Anglia. Her home page has some good further links.

Anyhow, it's curious that the sinks are trending towards more negative values
and I wonder if maybe perhaps the GDP method of estimating emissions is biased
as the residual chart (figure 2 e) appears to generally be accumulating.

Yes, it is interesting; the residuals are large, which is a good indication of how much still is unknown about the carbon cycle.

I don't think GDP is used to estimate emissions. The connection between GDP and emissions is an observation given the data on each one, and the paper speaks of a need to decouple this observed relationship. Emissions are estimated from energy statistics, according to the associated http://lgmacweb.env.uea.ac.uk/lequere/co2/carbon_budget.htm webste, same link as I gave previously for the tabulation of data used in this paper.

All the charts in figure 2 have error bars indicated. The largest uncertainties are associated with carbon sinks on the land; both the indirect emissions (figure 2a) from land use changes and the highly uncertain terrestrial sinks (figure 2c).

The residual is basically a count of how much carbon is missing after they add up the emissions and the estimates for sinks. The comment in the paper itself is:

Our estimates of sources and sinks of CO₂ were based on largely independent data and methods. Thus, when all the sources and sinks were summed every year they did not necessarily add to zero, because of the errors in the various methods. The sum of all CO₂ sources and sinks, which we call the ‘residual’, spanned a range of ±2.1 Pg C yr⁻¹ (Fig. 2e). This residual was not explained by the atmospheric CO₂ growth rate, the CO₂ emissions from fossil fuel combustion or the ocean uptake, because the uncertainties in these components were much smaller than the variability of the residual. Errors in LUC flux may explain a small part of the residual, for instance during the late 1990s, when fires in Indonesia were partly caused by land clearance taking advantage of the drought conditions¹⁷. Our fire-based LUC anomalies for 1997 were 0.7 Pg C greater than normal and account for one-half of the residual for that year. Overall, the residual was most probably caused by the regional responses of terrestrial vegetation to climate variability, indicating that land models overestimated the response of vegetation to the relatively cool/wet La Niña-like climatic conditions of the mid 1970s and underestimated the response to the volcanic eruption of Mount Pinatubo, in the Philippines, in the early 1990s. This later underestimation has been explained elsewhere as resulting from a missing response in the models to the aerosol-induced increase in the diffuse-light component of surface irradiance, and the subsequent enhancement of light penetration into vegetation canopies²⁹.​

From the tabulations, you can use a spread sheet to verify that in fact, the residuals are on average slightly positive with a small trend to being more positive; but of course they are all over the place in general. (Mean 0.273, sd 0.957) (Caution: the tabulation uses slightly different sign conventions to the diagram.) If the paper is correct in supposing that the greatest part of this is due to inaccuracies in estimating how vegetation is taking up CO₂, it would mean that some years over estimate and other years underestimate the amount of carbon taken into this sink.

A positive residual means either over estimated emission or (much more likely) underestimated sinks. Hence: "missing sink".

Cheers -- sylas

 

[Mark44]

Corinne Le Quéré is Professor of Environmental Sciences at the University of East Anglia.

The home of the Hadley CRU, which has come under a serious cloud in the last week or two.

 

[Mark44]

The Copenhagen Disagnosis​

Freudian slip?

 

[sylas]

The home of the Hadley CRU, which has come under a serious cloud in the last week or two.

That's a classic ad hominem; and worse, an indirect smear. It's highly inappropriate.

She's not in the CRU. She's not in any of the emails, except in one case that was an enormous cc to hundreds of scientists all over the world. There's nothing linking her to anything in the whole CRU emails brouhaha. It isn't Hadley CRU, by the way. The Hadley Centre is part of the UK Met Office, a different thing entirely. It's a common confusion. And finally, although there are issues showing up in the hacked emails affair concerning how some CRU personnel responded to the excessive flood of FOI requests they were receiving, there is nothing there whatever to indicate anything wrong with the science.

None of the other co-authors to the paper are in the CRU either. Indeed, Le Quere is the only one of the 31 authors from the Uni of East Anglia. The others come from all over the world, and their contributions and affiliations are in the paper.

If you think there's a science issue, then that might be something for this forum, in a different thread I would suggest. Matters of policy and politics, such as how to deal with FOI or adequate openness with data and so on belong in the Politics and World Affairs forum.

I do understand that people are concerned, and want to have questions answered in relation to the hacked files. I have chosen to be firm to underline that this is actually very serious. Accusations of fraud, or malfeasance, or scientific misconduct, are serious matters. It's not okay just to slip in an insinuations like this in a public forum without some credible basis. Being at the same university doesn't count. Heck; even the emails don't count for much; though that's a different subject for the other forum since it isn't actually about the quality of the science itself. The thread to use at present is [thread=355595]this one[/thread] that is mainly about the hacked files affair.

Also, thanks for picking up my Freudian slip. I've fixed it!

Cheers -- Sylas.

PS. How many Freudian psychologists does it take to change a light bulb?

Answer: Two. One to fit the new bulb, and another to hold my p... THE LADDER. I mean the ladder.

 

[Xnn]

Naty1 & Mark44;

There is clearly a heated political debate concerning what to do about
global warming and that is all well and good. However, the science is
robust enough that attempts to suggest that CO2 emissions are not
at the root of it fall short of being credible.

 

[sylas]

The wider questions seem to be things like... is global warming real? is it caused by human activities?

The answers to those two questions are actually very straightforward. It's yes, and yes.

Nice try; but such speculation is political in nature not scientific...

It is not speculation. It is not political. It is basic science independent of any political or policy concerns, based on measurement and elementary physics, and not in any credible scientific dispute. It is a starting point for looking at all the many more interesting open questions in climate science that are now a focus of active research and investigation. It is also a good starting point for the goal of basic science education, which is what I see as the main role of physicsforums.

These two points don't resolve the big political questions surrounding climate; but they do form a kind of basic solid ground that can be used no matter what your political or policy preferences.

Measuring global warming

The measurement of temperature increase can be seen in multiple independent research efforts, and they all give the same result to within measurement accuracies; a strong overall warming trend over the twentieth century, becoming particularly strong since about 1975, generally stronger over the land than the ocean. There is no published research indicating this is incorrect or giving any substantially different result. It really ought to be an elementary starting point for the scientific discussions of how the warming trend is measured, what values can be given to it, what causes it, how it is distributed regionally, and so on.

References:

• HadCRUT3 dataset; described in Brohan, P. et. al. (2006) http://www.agu.org/pubs/crossref/2006/2005JD006548.shtml, in J. Geophysical Research 111, D12106, doi:10.1029/2005JD006548.
  Pdf preprint http://www.cru.uea.ac.uk/cru/data/temperature/HadCRUT3_accepted.pdf .
• GISS dataset; described in Hansen, J., et. al. (2006) http://www.pnas.org/content/103/39/14288, in PNAS 103, pp 14288-14293, doi:10.1073/pnas.0606291103.
  Preprint here; data downloads, including summaries and full gridded data: at Goddard Institute for Space Sciences, NASA.
• NOAA/NCDC dataset; described in Smith, T.M., and Reynolds R.W. (2005), A global merged land air and sea surface temperature reconstruction based on historical observations (1880-1997), in J. Climate, 18(12), pp 2021-2036, doi:10.1175/JCLI3362.1
  Pdf preprint http://lwf.ncdc.noaa.gov/oa/climate/research/Smith-Reynolds-dataset-2005.pdf .

The cause of warming

The measured warming trend is substantial, and has a cause. There have been many factors that are involved in the changes of global temperature over Earth's long history. The change in this specific instance is primarily from an enhanced atmospheric greenhouse effect; and that is being driven by human activities.

There are still many open questions about quantifying the temperature response of Earth to the changing energy balance. It is a solid discovery, however, that human activities have made a substantial change to the Earth's atmosphere, and this has substantially increased the atmospheric greenhouse effect. The factors the drive changing temperatures are called forcings; and all the research that actually quantifies these gives the same result; anthropogenic greenhouse effect is the dominant factor over the twentieth century and especially in the latter half, where we have the best measurements and the strongest warming.

References:

• Meehl, G.A. et al., (2004) Combinations of Natural and Anthropogenic Forcings in Twentieth-Century Climate, in Journal of Climate 19, 3721-3727, doi: 10.1175/1520-0442(2004)017<3721:CONAAF>2.0.CO;2. Pdf preprint at UCAR.
• Tett, S.F.B et. al. (2007) The impact of natural and anthropogenic forcings on climate and hydrology since 1550, in Climate Dynamics, 28(1), pp 3-24, doi:10.1007/s00382-006-0165-1.

It would be easy to go on; but my aim is not to simply overwhelm with references. The point is that the answers to these two rather basic questions that I am giving are not politics, but really are science. Furthermore the confidence given in these answers is very high.

There are other questions, such as estimates of sensitivity, or details of the carbon cycle, or all kinds of other things, where the literature will be expressed quite cautiously and with acknowledgment of large uncertainties.

The two questions I have proposed, however, are not really in that category. They are legitimately discoveries; and a backdrop to all the truly open questions. Everything in science is in principle open to question and revision; you never get absolute certainty in anything. But IMO there's really not any credible prospect of getting these questions answered with any meaningful additional confidence -- only with more precision.

I appreciate that there are many people who are skeptical of the answers I have given to these two questions. The question is -- is there any actual scientific basis for withholding basic assent to these answers? If so, then given the guidelines for the forum, you should provide some peer reviewed reference, or credible equivalent, and we can look at the scientific case on its own merits. I don't think there is any such literature except possibly a handful of isolated and minimal impact papers of dubious worth on their own immediate merits; but I truly am interested and open to suggestions if you disagree. Just make sure that they do address the questions at issue; and not some other less strongly constrained matter.

Other matters

In your post, you raise a number of further peripheral matters that I think would be better taken up elsewhere, if at all. I am quoting extracts; linked back to the original as usual.

... 38,000 scientists ... strongly disagree about man made causes of climate change.

Even in Australia ... government there remains in turmoil over man made global warming ...

The legitimate answers to those two questions is ACTUALLY dependent on valid data, valid scientific theory, and models that work...NOT what East Anglica "scientists" concocked/invented/created fraudulently for the IPCC.

The Earth IS likely warming, just like it has thousands of times in the past...

One recent recent study shows ... ...besides, whose to say that a warmer climate would not be a big net plus?...

The petition you allude to is notorious; and further discussion on that belongs in the politics forum. The implosion of our liberal party over climate issues would be very relevant in the politics forum. There is no indication whatever of invalid data or theory in the CRU hack affair, but discussion of that belongs in the politics forum. Your comment that the Earth likely IS warming appears to be agreement with my first point; if you can just recognize that this is actually a measurement. Changes in the past and in the future, for all kinds of reasons, are not in dispute. This says nothing about the specifics of what in particular is driving the change in the present. Your recent study requires a citation. It may well be a paper I have recently blogged about, along with three others in my PF blog as https://www.physicsforums.com/blog.php?b=1493 . If so, it has been discussed here before; but I'm very familiar with it and happy to consider it again in the main forums. The question of whether changes in climate are "good" or "bad" is another irrelevancy to the scientific question raised here; let's not have politics or policy distort consideration of scientific answers to the two questions.

Cheers -- sylas

 

[Mark44]

Naty1 & Mark44;

There is clearly a heated political debate concerning what to do about
global warming and that is all well and good. However, the science is
robust enough that attempts to suggest that CO2 emissions are not
at the root of it fall short of being credible.

There is also a scientific debate about whether the Earth is warming at all, with some climate scientists predicting a major cooling period in the next 20 years in their peer-reviewed paper (Zhen-Shan, L. and S. Xian. 2007. Multi-scale analysis of global temperature changes and trend of a drop in temperature in the next 20 years. Meteorology and Atmospheric Physics, 95, 115–121.)

For science that is supposedly "robust" there are certainly lots of scientifically trained people who aren't buying it. The Global Warming Petition Project (http://www.petitionproject.org) has had over 30,000 signers, of which over 9,000 hold PhDs. The following is one of the two paragraphs that make up this petition.

“There is no convincing scientific evidence that human release of carbon dioxide,
methane, or other greenhouse gasses is causing or will, in the foreseeable future, cause
catastrophic heating of the Earth’s atmosphere and disruption of the Earth’s climate.
Moreover, there is substantial scientific evidence that increases in atmospheric carbon
dioxide produce many beneficial effects upon the natural plant and animal environments
of the Earth.”​

Information about the signers includes their professions, broken down as follows (I have rounded the numbers)
atmospheric, environmental, or Earth sciences - 3800
mathematics or computer science - 900
physics and aerospace sciences - 5800
chemistry - 4800
biology and agriculture - 3000
medicine - 3000
engineering and general science - 10,000

The academic credentials of the signers are broken down by degrees attained, with ~9000 PhDs, ~7000 MS, ~2600 MD or DVM, and ~12,700 BS or equivalent.

Granted, science is not and should not be a democratic process, so the numbers for and against a particular theory are for the most part irrelevant. My point is that for science that is "settled" there sure are a lot of people who don't think so.

 

[sylas]

There is also a scientific debate about whether the Earth is warming at all, with some climate scientists predicting a major cooling period in the next 20 years in their peer-reviewed paper (Zhen-Shan, L. and S. Xian. 2007. Multi-scale analysis of global temperature changes and trend of a drop in temperature in the next 20 years. Meteorology and Atmospheric Physics, 95, 115–121.)

Excellent... a valid reference. I am genuinely interested in this and appreciate the link; I have found the paper and had a look at it.

• Lin Zhen-Shan and Sun Xian (2007) Multi-scale analysis of global temperature changes and trend of a drop in temperature in the next 20 years, in Meteorology and Atmospheric Physics, Vol 95, Iss 1-2, pp 115-121, doi:10.1007/s00703-006-0199-2
  Also http://www.crikey.com.au/Media/docs/Zhen-Shan--Xiuan-MeteorAtmosPhys-2007-d1227bc1-3183-456f-a935-69c263af1904.pdf .

The method used is a kind of curve fitting process called "Empirical Mode Decomposition". This is similar to Fourier analysis, but it is performed in the time domain. I had not heard of it before, but it certainly looks very interesting indeed. There seems to be significant interest in this technique, and I am going to look at it more carefully and consider using it myself as possible analysis method.

A good reference to explain the method (and more readable) is:

• Zhaohua Wu, Norden E. Huang, Steven R. Long, and Chung-Kang Peng (2007) On the trend, detrending, and variability of nonlinear and nonstationary time series, in PNAS 104(38), 18 Sep 2007, pp 14889–14894, doi:10.1073/pnas.0701020104.

Wu et al (2007) is a mathematical paper rather than a climate paper; but this publication uses the global temperature anomaly as an illustrative example, which makes it particularly relevant. Professor Huang is the major developer of the method, which is also the basis for the Hilbert-Huang transform.

In the process of looking at this I am now drafting a post that may be better in a thread of its own; but I want to post this much now to acknowledge a useful reference with thanks. This method, and both the papers, actually obtain pretty much the same underlying trend as the references I have given. Using this technique, it appears as a residual function after removing the "stationary" (quasi-periodic) intrinsic mode functions, which represent cyclic variations in the signal. The trend is not linear; but it gives the same total amount of warming as other methods I have cited above -- as we should expect, since this is still precisely the same physical measurements involved. That is, this is not new data. This is clear in both the references cited. Furthermore Lin and Sun (2007) explicitly identifies CO₂ as the major factor in the trend; ironically it therefore is also answering "yes" to the two questions I have proposed.

The point at issue is the added variance on top of the central trend from a multi-decadal cycle revealed in the analysis; and for which no physical cause is known -- as the reference itself makes clear. This variance is exceptionally large in the Sun and Lin paper, and hence leads them to propose the possibility of an extended but temporary fall in global temperatures in coming decades. The fall is explicitly temporary, as the multi-decadal variance, by definition, has no trend. There are reasons to be dubious of extending the analysis as a projection in this way; but I'll leave that to a subsequent post.

The Sun and Lin paper has not had much impact at all. The other paper gives a smaller magnitude for the multi-decadal cyclic component and no expectation of a fall in temperatures. Neither one, I suggest, can really be used to give a safe projection; but I'll take that up later.

For science that is supposedly "robust" there are certainly lots of scientifically trained people who aren't buying it. The Global Warming Petition Project [...]

Granted, science is not and should not be a democratic process, so the numbers for and against a particular theory are for the most part irrelevant. My point is that for science that is "settled" there sure are a lot of people who don't think so.

I don't dispute your final sentence; nor do I find it all that unusual. I know of several such cases like this, where science is disputed by a lot of people, including many who have some science training, despite the points at issue being considered settled by almost all the scientists actively working on it. However, why that occurs and to what extent is off topic for this thread, and indeed for this whole Earth forum.

If there are actual scientific arguments to raise, that can be done here; and as you note the numbers don't matter. As Einstein once famously remarked, in response to a pamphlet entitled 100 Authors Against Einstein: "If I were wrong, one would be enough."

Cheers -- sylas

 

[vanesch]

It follows that there is a need for scientists to communicate better, to a wider audience; not just the general public but governments and other policy makers. The IPCC reports are driven by this requirement.

Scientific communication, especially towards the public, should have some soberness to it. Note that it's not only in climate science that a certain way of communicating in an advertisement-style works on my nerves ; I already had that feeling in my own original field of particle physics, when crazy claims of "exploring the big bang" and so on were made in order to advertise for the LHC for instance.

I think in the long term, science wins by having some soberness to it - although immediate funding maybe not.

The interaction between science and politics and policy, in any ideal world, should be like the following:

• The conclusions reached by science need to be obtained without any deference to policy implications of the conclusions. Science ideally seeks answers and confidence limits on those answers based exclusively on what the evidence and research actually can show.
• The questions and issues addressed by scientists, however, might well be driven by secondary requirements of what is deemed important to know, for policy reasons.

Indeed. That's my point. This report isn't at all like this, and it is what is disturbing me.

Precisely how we improve the communication of credible science is a good question; but anything you do along those lines should be in the way of providing accessible information.

The accessibility is not to be confused with trading emotion and rhetoric for complication.

I think this only looks like an advertisement because there is such a gaping disconnect between what is happening in the world of science and what is being debated in the political world. There are a heap of open questions in climate science and all kinds of large uncertainties. But they are not the same as the major uncertainties debated more widely.

No, it looks like an advertisement because the same communication techniques are used as in advertisements: implicit associations (look at all the - beautiful, that's true - irrelevant, but emotionally loaded pictures that are scattered around the report (of dried-out trees in a desert and so on) ; look at all the emotionally engaging qualifiers used throughout the text. This report is not just trying to convey information, it is trying to convey a desire for action. Like a commercial is trying to convey a desire to buy or something and uses similar techniques.

You can see this by the imbalance between the statements. For instance, the *greening* of the Sahel and part of the Sahara is mentioned only very briefly (although scattered with "drying out" pictures). Even though it is said that this is probably an important effect, nowhere this is found in any conclusion. The fact that temperate regions might receive MORE precipitation is also not to rhyme with the general spirit of a barren, hot, dried-out world they want to sell. All this is pretty much "advertisement language". This is not "popular science" simplification.

When you look at a pseudo-scientific ad for a new SUV, you might see similar things: some scientific data about emissions, rpm/couple, braking,... with scattered pictures of strong men on an adventurous trip in wild nature and pretty girls full of admiration, trying to convey the desire to buy such a car, by association with certain emotions. It's no different here.

 

[Andre]

...The fact that temperate regions might receive MORE precipitation...

What does that imply for a previous discussion?

 

[vanesch]

What does that imply for a previous discussion?

Higher levels of humidity in the atmosphere, of course

 

[sylas]

Communicating Climate Science

Scientific communication, especially towards the public, should have some soberness to it.

There's a huge issue with how best to communicate scientific information to the wider public, and this is not actually a question of the science itself, but a matter of communications skills, or styles.

It is, to some extent, subjective; and in my view it is good to have a range of styles of communication in place. It's commonly held that the problem with science communication is precisely the reverse. It is often TOO dry and sober and dispassionate. But there you go.

I don't actually agree with or even really understand your reaction in this case; but I don't think it is all that important. The aspects I like about this report are that it is clear and concise, and starts out each section with simple bullet points that speak directly to what is most relevant for the intended audience; and also that it tackles head on many of the common popular confusions and outright errors that plague the whole popular perceptions of climate science. It is also well referenced to all the conventional dry technical literature.

Note that it's not only in climate science that a certain way of communicating in an advertisement-style works on my nerves ; I already had that feeling in my own original field of particle physics, when crazy claims of "exploring the big bang" and so on were made in order to advertise for the LHC for instance.

I don't think that is a valid comparison. If there was anything actually "crazy" in this report, then I'd agree, and that is a question I am willing to take up on its own merits. Are there any valid concerns with content here, rather than with style? I mean that as a serious question. I appreciate that different people may have different preferences for style; but leaving that aside... I think the biggest reason a report like this is needed is that many people instinctively think there's something dubious or crazy or far fetched about the content.

This thread would be a good place to consider such issues on their own scientific merits.

As for sober scientists at the LHC... I can't resist. Did you like the LHC rap (youtube link)? I was very impressed with this communication effort. I was also impressed with how CERN reacted to the appalling book Angels and Demons by Dan Brown. (Some folks liked it as a book; but its not my style...) They made it an opportunity to tap into public interest and help people learn more about the science. See http://angelsanddemons.cern.ch/.

You can see this by the imbalance between the statements. For instance, the *greening* of the Sahel and part of the Sahara is mentioned only very briefly (although scattered with "drying out" pictures). Even though it is said that this is probably an important effect, nowhere this is found in any conclusion. The fact that temperate regions might receive MORE precipitation is also not to rhyme with the general spirit of a barren, hot, dried-out world they want to sell. All this is pretty much "advertisement language". This is not "popular science" simplification.

Point taken. The pictures are style and presentation; I grant that it won't be to everyone's taste. On the other hand, I personally think it is a reasonable reflection of the general conclusions being reached about likely impacts; valid as content. Of course, it is not presented simply as a conclusion in text but as a kind of indirect stylist accompaniment. I don't have a strong negative reaction to that. Popular presentations can and should consider the effective use of images to help convey a message... as long as the message itself remains sound.

The text doesn't actually use the adjective "important" of the Sahel; it uses "rare" (p43):

Perversely, if the WAM circulation collapses, this could lead to wetting of parts of the Sahel as moist air is drawn in from the Atlantic to the West (Cook and Vizy 2006; Patricola and Cook 2008), greening the region in what would be a rare example of a positive tipping point.​

The report seems to be a reasonable account of the risks associated with changing climate. There are more negative consequences than positive ones, and all of them are given with limited confidence. It is a matter of risk assessment, and it's not simply that "temperate regions" will get more, or less precipitation. It varies with the region. Australia, unfortunately for me, it likely to become ever dryer. The Amazon is also at risk of increased drought. That section of the report is actually bracketed with a picture of flood (p41) and another of drought (p44). It's not simply a case of looking for the worst in every case. It is rather a consequence of the fact that we are adapted to a certain distribution of climate conditions, and rapid changes therefore tend to be disruptive rather than productive, for the most part.

The report is unabashed in the conclusion that climate change is a problem and something that should be mitigated against. I think this is an example of the proper roles of science and of policy. What the science says is that the consequences of changing climate are mostly negative and increasingly so with more rapid change. That's not science driven by policy. That's the answer science gives the questions legitimately asked by policy makers.

On page 52:

The Synthesis Report of the Copenhagen climate congress (Richardson et al. 2009), the largest climate science conference of 2009, concluded that "Temperature rises above 2 °C will be difficult for contemporary societies to cope with, and are likely to cause major societal and environmental disruptions through the rest of the century and beyond."​

Cheers -- sylas

 

[Andre]

Higher levels of humidity in the atmosphere, of course

Warm but is that all? Wouldn't it suggest that the water cycle would have to accellerate to bring more rain?

 

[Xnn]

Granted, science is not and should not be a democratic process, so the numbers for and against a particular theory are for the most part irrelevant. My point is that for science that is "settled" there sure are a lot of people who don't think so.

Mark44;

I looked over the abstract of the Lin Zhen-Shan and Sun Xian paper.
They are not predicting cooling. Instead, they are hypothesizing that if
CO2 levels were to be held constant and if the cyclic trends of the past
were to continue, then there could be cooling. However, we know that
CO2 levels are continuing to rise and they haven't shown that the 60
year trend isn't just a coincidence.

Also, the key word in that petition is "catastrophic heating". Humans are
remarkable good at adopting to climate change, so it's difficult to say
that the climate change that we are facing will be necessarily be catastrophic.
In fact, the IPCC has even documented that agriculture productivity will
initially increase due to global warming. So, I can see their point.

Anyhow, the science behind global warming due to CO2 emission is clear.
However, there is and ought to be an intelligent debate on what to do about it.

 

[Mark44]

Mark44;

I looked over the abstract of the Lin Zhen-Shan and Sun Xian paper.
They are not predicting cooling. Instead, they are hypothesizing that if
CO2 levels were to be held constant and if the cyclic trends of the past
were to continue, then there could be cooling. However, we know that
CO2 levels are continuing to rise and they haven't shown that the 60
year trend isn't just a coincidence.

If you look past the summary, you will see that they are predicting cooling in the next 20 years. In section 6, they say "It thus indicates that whether on century scale or on the periods of quasi 60-year oscillations, the global climate will be cooling down in the next 20 years."

Right after that they say "And again, our primary conclusion, i.e., that atmospheric CO2 concentration is not a key determinant of periodic variation of the global temperature. The global climate warming is not solely affected by the CO2 greenhouse effect.
The best example is temperature obviously cooling however atmospheric CO2 concentration is ascending from 1940s to 1970s."

Also, the key word in that petition is "catastrophic heating". Humans are
remarkable good at adopting to climate change, so it's difficult to say
that the climate change that we are facing will be necessarily be catastrophic.
In fact, the IPCC has even documented that agriculture productivity will
initially increase due to global warming. So, I can see their point.

Anyhow, the science behind global warming due to CO2 emission is clear.

I disagree, and there are many climate scientists more knowledgeable in this field than I who also disagree that global warming is caused by solely or primarily by CO2 increases. This point is also made in the introduction of the Zhen-Shan and Xian study; namely, that CO2 increases follow temperature increases, not the other way round - "And the past records have indicated that the increase of CO2 concentration did not occur before the warming up as shown by some studies (Fischer et al, 1999; Schlesinger and Ramankutty, 1994)"

However, there is and ought to be an intelligent debate on what to do about it.

 

[Mark44]

.

My point is that for science that is "settled" there sure are a lot of people who don't think so.

I don't dispute your final sentence; nor do I find it all that unusual. I know of several such cases like this, where science is disputed by a lot of people, including many who have some science training, despite the points at issue being considered settled by almost all the scientists actively working on it. However, why that occurs and to what extent is off topic for this thread, and indeed for this whole Earth forum.

I find it difficult to believe that a "science is settled" when two different camps of equally competent scientists hold views that are contradictory. Would you care to define "almost all" in your assertion that the points at issue are settled? And how does that justify the science? After all, in the time of Galileo Galilei, "almost all" of his fellow scientists looking at the Earth's relationship with the solar system concurred with the church dogma that the Sun revolved around the earth.

 

[vanesch]

There's a huge issue with how best to communicate scientific information to the wider public, and this is not actually a question of the science itself, but a matter of communications skills, or styles.

The point is that the *message* that is conveyed is more dependent on the style than on the content. That's the whole purpose of publicity btw. Communication is the art of taking factual material and presenting it in such a way that the desired message is conveyed, by using the factual information as a support for the rhetoric at hand. That's exactly what that SUV publicity does: there's no erroneous factual information in there. I'm sure that the curves of torque versus rpm are scientifically correct. But the whole is set up so that you get an impression of power, of pleasure etc... if you buy that car.

Here, the message is to urge people to go for ambitious goals at the Kopenhagen conference and to get popular support for it, based upon fear for the future and catastrophe, blood and drama.

While, if you really read the report, and you think about it, you arrive at a totally different conclusion (well, me at least). Look at figure 22. That's bluntly unfeasible. None of those paths are realistically attainable or will even be approached.

If you see that the result of Kyoto has been a 40% increase in CO2 exhaust, then it is clear that this kind of exhaust limitations on relatively short terms are a failure. So hoping for the drastic reductions on figure 22 is simply impossible.

On the other hand, the "tipping points" give us not such a dramatic scenario at all: greener Sahara, more available land (reduction of Amazon forest = more place for people, Greenland will become ice-free, parts of Antarctica will become ice-free), and the general "aride" desert picture that's everywhere in the booklet is visibly NOT the climate we will actually have, which seems to be more humid (more rain in moderate climate zones...).

So between an impossible reduction scheme of figure 22, and the not-so-bad consequences in the list of tipping points, I think that the wisest political decision, based on this report, is to put CO2 exhaust reduction to a lesser level of importance (although it should be pursued), and to start thinking of adapting to the new climate by the end of the century.

That's the message I personally get out of this report when looking at the science in it, and it is in total contradiction with the tone of the report.

It is, to some extent, subjective; and in my view it is good to have a range of styles of communication in place. It's commonly held that the problem with science communication is precisely the reverse. It is often TOO dry and sober and dispassionate. But there you go.

Because there's a difference between trying to convey information, and an UNDERSTANDING, and trying to convey a message and a desire for action. The first is science, the second is publicity and rhetoric.

I don't actually agree with or even really understand your reaction in this case; but I don't think it is all that important. The aspects I like about this report are that it is clear and concise, and starts out each section with simple bullet points that speak directly to what is most relevant for the intended audience; and also that it tackles head on many of the common popular confusions and outright errors that plague the whole popular perceptions of climate science. It is also well referenced to all the conventional dry technical literature.

The text in itself, or at least the contents of the text, is ok. It is the "drama" that goes with it that makes me tip over. From the moment that one tries to sell me some desire or action, I consider that I have to do with an "argument" and not with "a source of information". One is not trying to "inform me" (explain me how things work), but one is trying to induce me into action or desire. Both are incompatible. You cannot "inform" (and show yourself balanced) and at the same time "argue" (and pull someone over). Yes, you can first "inform" and then consider different positions, and explain why one position is probably preferable over another.

In this text, at no point one considers other positions than "we have to reduce drastically our emissions and right now because we're heading for an even worse catastrophe than we thought 5 years ago".

This thread would be a good place to consider such issues on their own scientific merits.

I still have to go through the many references given here, but the first point that hit me was that the plot on figure 2 does seem to show that there is a steady, linear, rise of CO2 content in the atmosphere. Just by looking at the plot, and putting a ruler over it (yes, there has been a slight slowing down in the 1990-ies).

So what's all the buzz over this acceleration in CO2 ? It might be correct, but then it needs to be explained, right ? How can you show a linear rise in the atmosphere, and dedicate a whole part of the report over the increasing exhaust, and not explain how both are to be compatible ?

I was also impressed with how CERN reacted to the appalling book Angels and Demons by Dan Brown. (Some folks liked it as a book; but its not my style...) They made it an opportunity to tap into public interest and help people learn more about the science. See http://angelsanddemons.cern.ch/.

This is OT, but CERN has a great [STRIKE]publicity[/STRIKE] public relations department...

 

[vanesch]

Figure 2 is completely consistent with the numbers given. The rate of increase IS increasing and you can see quite easily that the increase since 1980 is not linear. Just hold a ruler up against the graph if you want to check. Of course, the proper measure of linearity works from the numbers, not eyeballing a graph, and the numbers are as you have quoted from the report. What’s the problem?

Ok, maybe somewhat cheap, but here's my "ruler" on that figure, just done "by hand". We see that in the 90ies there was indeed a dip, and that now, we are somewhat above the slope. So I can indeed see that if you pick out exactly the right "pieces of graph", you get out the numbers in the paper. However, doing things "with the ruler" doesn't give you that impression. So I do think this needed some explanation.

 

[vanesch]

There's another very misleading figure, and that's figure 9.
Although I don't question the plot, what I find very misleading are the insets, of the Greenland ice cover, cherry-picked to be 1992 (exceptionally low melt area) and 2007 (exceptionally high melt area), both are not representative of the average trend (probably correctly done on the plot). I connected the "trend line" that connects these 1992 and 2007 points, to convey the "slope" that the insets are suggesting, as compared to the "scientifically correct" slope.

There's nothing factually wrong, nowhere. But it is presented in such a way that people get a wrong impression. That's advertising. That's not informing.

Again, I'm not disputing any of these numbers, I'm disputing the *representation* and the underlying message.

 

[GENIERE]

There is also interesting empirical data:

North Pole webcam photo of April 4, 2007 about a month after expected maximum ice extant. 2007 is the year said to have the least summer ice coverage.

http://www.arctic.noaa.gov/npole/2007/images/noaa1-2007-0425-102422.jpg


USS Skate (SSN-578), surfaced at the North Pole, 17 March 1959. The date was specifically chosen due to it being the time of maximum ice extant.

http://www.navsource.org/archives/08/0857806.jpg


North Pole in August 2007, worst summer ever compared to summers of 1979 - 2000!

http://www.arctic.noaa.gov/npole/2007/images/noaa2-2007-0803-065037.jpg


Seadragon (SSN-584), foreground, and her sister Skate (SSN-578) during a rendezvous at the North Pole in August 1962. Note the men on the ice beyond the submarines.

http://www.navsource.org/archives/08/0858411.jpg

<|>

 

[mheslep]

The point is that the *message* that is conveyed is more dependent on the style than on the content. That's the whole purpose of publicity btw. Communication is the art of taking factual material and presenting it in such a way that the desired message is conveyed, by using the factual information as a support for the rhetoric at hand. That's exactly what that SUV publicity does: there's no erroneous factual information in there. I'm sure that the curves of torque versus rpm are scientifically correct. But the whole is set up so that you get an impression of power, of pleasure etc... if you buy that car...

At least they didn't air brush cyclones into the page 8 Earth photo as Gore did in his http://ecx.images-amazon.com/images/I/41RLwu-GDFL._SL500_AA240_.jpg"

 

[Xnn]

Geniere;

I wouldn't put much stock into sub photographs.
They tend to scout out open floes before surfacing; it's safer!

Mark44;

I see the statement in section 6; it's different than what's in their summary.
So, much for consistency of their report.

However, the point is that they are just curve fitting; that's not scientific.
It reminds me of the people that curve fit stock prices and try to sell it
as a sophiscated method of investing. If stock prices and the climate were
purely cyclic then it would work, but we know that there are drivers to the climate
as there are to finances.

Their selection of quasi periodic cycles is suspect. In particular, examine how they
drew the 60 year cycle in Figures 1,2 and 5. It's an increasing amplitude with the strongest positive forcing over the last 30 years. That works to minimize
the warming trend from CO2. So, the analysis is dependant on the quasi 60
year period cycle leading to cooling. However, where is the science for that?

It's also only over the last 50 years that human CO2 emissions have dominated
the climate. Before that, natural variations were dominate. So, they are
curve fitting 2 different time periods and exaggerating cyclic warming over
the last 30.

Personally, I wouldn't put a dollar into their approach. It's far better to anticipate
about 0.015C of warming per year from CO2 increases superimposed upon a quasi periodic El Nino/La Nina of about 0.25C over a 3 to 7 year frequency. There are also
the quasi periodic 11 year solar cycles of about 0.05C, but they can not be discerned
in the global temperarure record compared to ENSO events.

 

[mheslep]

...
So what's all the buzz over this acceleration in CO2 ? It might be correct, but then it needs to be explained, right ? How can you show a linear rise in the atmosphere, and dedicate a whole part of the report over the increasing exhaust, and not explain how both are to be compatible ?

Global emissions have accelerated, but atmospheric accumulation, i.e. figure 2, is experiencing more or less a linear increase.

This graph also illustrates, BTW, why CO2 emissions reductions enforced on only the EU and the US while allowing China and India to opt out would be useless.

 

[Bored Wombat]

This graph also illustrates, BTW, why CO2 emissions reductions enforced on only the EU and the US while allowing China and India to opt out would be useless.

Well it wouldn't be immediately effective, but useless is a bit strong.

Every little less carbon emitted is a retardation of climate change.

And demanding CO2 emissions reductions in US and EU would force the development of low carbon technologies that could then be passed on to China, India and Brazil.