SRES: A Big Discussion in1998

Posted: March 16, 2013 by tallbloke in climate, Forecasting, Measurement, methodology, Uncertainty
Tags:

all.7z 907290134

cc: xxx@thames.iiasa.ac.at, xxx@thames.iiasa.ac.at
date: Thu, 01 Oct 1998 19:52:19 +0200
from: Nebojsa NAKICENOVIC <xxx@iiasa.ac.at>
subject: SRES Discussion Group
to: sres@iiasa.ac.at

Dear Colleagues,

I would like to initiate a discussion group so that we can all share
comments and suggestions we receive on the set of scenarios posted on the
web-site and other sources. This message will be forwarded to all of you
who have contributed to SRES activities at some time. Please let me know
by return e-mail if you want your name removed from the discussion group.

David Griggs, from IPCC Working Group 1 Technical Support Unit, organized a
similar scenario discussion group for climate modelers and other colleagues
in IPCC. It produced very useful critique of our work and suggestions how
to make our scenarios more useful to the climate modeling community. For
your information, I have attached all e-mails concerning SRES scenarios
that have reached me through this discussion group.

I hope that you will all receive this message before you leave for Beijing.
At the meeting, we can decide which topics should be on the discussion
list in the foreseeable future. My objective is to generate more
transparency and that you are all informed in real time about various
exchanges within the SRES writing team and with various scenario user
groups. In the meantime, please feel free to raise issues that are in your
view of concern to the whole writing team.

Best regards, Naki

Attachement: e-mails from WGI scenario discussion group.

************************************************
Date: Mon, 07 Sep 1998 17:43:12 +0200
From: xxx@climate.unibe.ch
Subject: Re: Emission Scenarios Electronic Conference
Sender: owner-scenarios@meto.gov.uk
To: scenarios@meto.gov.uk
Cc:xxx@climate.unibe.ch
X-MTS: smtp

Dear Colleagues,

First, I would like to say that I appreciate all the tremendous work the
scenario group has done so far. I would like to congratulate the group to
their
progress. In the following, a few points are raised that may be unresolved.

For the TAR, we need to have emission scenarios
(1) for all relevant anthropogenic greenhous agents
(2) that include all relevant anthropogenic sources
(3) that are in agreement within uncertainties with emission
estimates provided in the SAR for 1990 and if possible
with more up to date estimates (e.g. numbers for fossil
fuel CO2 emissions are available up to 1996).
(4) that are in a form as needed by chemistry and carbon
modellers to convert emissions into concentrations.

>From the WWW site sres.ciesin.org it appears that only the RIVM-Image
model does
provide (at least until now) emissions for the most important greenhouse
gases.

‘Other CO2’, N2O, CFC/HFC, PFC, SF6, CO, NMVOC, NOx emissions are missing for
the IASA model.

CFC/HFC, PFC, SF6, NMVOC, emissions are missing for the EPA and NIES model.

Atmospheric chemistry modellers need emissions by individual species (e.g.
see
Table 2.5 in SAR, p 97 ff). Is this information available?

In the SAR average anthropogenic CH4 sources were estimated to be in the
range
300-400 Tg(CH4)/yr for the 1980-90 decade. The IASA model yields an
emission of
67.9 (probably fossil fuel related only) and the NIES model of 281
Tg(CH4)/yr.

In the 1994 report, anthropogenic N20 emissions were estimated to be in the
range of 3.3.-7.7 TgN/yr again for the 1980 decade. The RIVM model yields for
1990 an emission of 10.5 TgN/yr while the NIES model yields 2.4 TgN/yr.

If using numbers outside the SAR range, we would need to have a sound
scientific
explanation for the difference.

Confronted with this incomplete information, it is not possible for me to
suggest which one of the proposed scenarios should be used in TAR.

In this context, I am also wondering whether results for the 4 scenarios are
available for all models.

Carbon modelling:
——————
One does not necessarily need net emissions by land use changes in simple
models. A minimal requirement is that net emissions by land use changes are
included in the total emission estimate.

More complex biospheric model need information how individual grid cells are
affected by land use changes. Thus, a land use data base describing the
conversion between different types of ecosystems and managed land may be
produced.

Net carbon emissions may also be split into main categories such as fossil,
cement production, tropical and northern hemisphere land use changes.

The fossil fuel scenario data should in my opinion match the most recent
carbon
emission figures to avoid any boring discussions and critics.

I hope this is useful.

With best regards,

Fortunat

************************************************
Content-return: allowed
Date: Mon, 07 Sep 1998 17:30:04 +0100
From: “Noguer, Maria” <xxx@meto.gov.uk>
Subject: from Colin Johnson – marker scenario intercomparison
Sender: owner-scenarios@meto.gov.uk
To: “scenarios,” <scenarios@meto.gov.uk>

Scenario Intercomparison
————————

I have compiled the following summary tables to aid comparisons between
the four new IPCC scenarios and with IS92a. A short description of the
new
scenarios is give on the web site.
Note that scenarios A1 and A2 have variants, but the ones listed are
the only information I was able to obtain today from the web site.
Details for IS92a are from Pepper et al. (1992) – ‘Emission scenarios
for
the IPCC An Update’. Information for 2020 from IS92a was obtained by
linear interpolation between 2000 and 2025.

A few comments: A2 has no biomass fuels, and B2 has no details of
land surface processes – see the methane emissions. It is impossible
to compare emission totals where these include natural processes as
we do not have the full details. For example, I am uncertain if
biomass
burning emissions have been included. B2 has no CO, NOx or N2O
emissions
specified yet.

Colin Johnson, Hadley Centre, 7-IX-98

1. Fossil Fuel CO2 in Gt/yr as [C].

Scenario 1990 2020 2050 2100
__________________________________________
A1B 6.0 12.1 16.0 13.1

A2.1 6.2 11.1 18.5 29.9

B1 6.1 7.5 9.0 5.7

B2 5.9 9.3 11.2 13.9

IS92a 6.0 10.0 13.2 19.8
__________________________________________

2. Primary Energy in EJ/yr, and fossil fuel fraction (%).

Scenario 1990 2020 2050 2100
__________________________________________
A1B 345 648 1204 2079
(81) (82) (60) (31)

A2.1 330 611 984 1589
(95) (94) (91) (81)

B1 348 475 680 820
(80) (78) (63) (31)

B2 351 567 869 1356
(82) (82) (70) (51)

IS92a 344 648 934 1453
(88) (85) (74) (64)
__________________________________________

3. Global population in millions.

Scenario 1990 2020 2050 2100
__________________________________________
A1B 5262 7493 8704 7056

A2.1 5263 8191 11296 15068

B1 5297 7767 8933 7239

B2 5262 7672 9367 10414

IS92a 5252 7972 10031 11312
__________________________________________

4. Primary Energy Use per Capita (GJ/yr).

Scenario 1990 2020 2050 2100
__________________________________________
A1B 66 86 138 295

A2.1 63 74 87 105

B1 66 61 76 113

B2 67 74 93 130

IS92a 65 80 93 128
__________________________________________

5. Methane Emission in Tg/yr.

Scenario 1990 2020 2050 2100
__________________________________________
A1B 281 366 338 274

A2.1 309 444 643 923

B1 429 495 543 478

B2 68 87 104 188

IS92a 506 636 785 917
__________________________________________

6. Sulphur Emissions in Tg/yr as [S].

Scenario 1990 2020 2050 2100
__________________________________________
A1B 69 102 64 24

A2.1 77 106 109 57

B1 71 43 53 31

B2 58 40 21 12

IS92a (all) 98 133 141 169
IS92a (energy+
industry) 73 109 151 144
__________________________________________

*************************************************
 Dr. Maria Noguer 
IPCC WGI Technical Support Unit 
Hadley Centre  
Met Office 
London Road 
Bracknell
Berks, RG12 2SY
UK

Tel: +44 (0) 1344 854938
Fax: +44 (0) 1344 856912 
Email: xxx@meto.gov.uk  

************************************************
8/9/98 (from Maria Noguer)

Dear colleagues,

For those of you without access to excel, please find below the three main
tables from Naki. I have not included the emissions trajectories Table, I
would
suggest to wait until they are on the SRES site (early August).

For those of you that cannot read attachments, I will send you the brief
description of SRES activities that Naki sent in the next Email.

Regards,

Maria Noguer

———–

GLOBAL ENERGY RELATED EMISSIONS IPCC SRES B2 Marker Scenario

CO2 [MtC] CH4 [MtCH4] SO2 [MtS] N2O [MtN]** CO [MtC]* NOx [MtN]*
1990 5900 68 59 n.e. 190 23
2000 7393 75 59 n.e. 201 28
2010 8268 80 52 n.e. 210 32
2020 9234 87 40 n.e. 231 38
2030 10254 92 33 n.e. 248 44
2040 11040 100 27 n.e. 259 49
2050 11313 104 21 n.e. 254 51
2060 11806 113 17 n.e. 244 52
2070 11979 126 14 n.e. 228 52
2080 12566 146 12 n.e. 212 57
2090 13274 164 12 n.e. 199 62
2100 13939 188 12 n.e. 189 61
* Provisional estimates
** Not modeled as flows are less than 10% of anthropogenic emissions

GLOBAL NON-ENERGY RELATED ANTROPOGENIC EMISSIONS IPCC SRES B2

CO2 [MtC]** CH4 [MtCH4]** SOx [MtS]* N2O [MtN]** CO [MtC]* NOx
[MtN]*
1990 1165 213 10 2 227 8
2000 1534 215 12 3 245 8
2010 1658 238 12 3 253 9
2020 1012 248 14 3 231 8
2030 913 254 15 3 231 8
2040 294 233 17 3 183 8
2050 -324 217 17 3 208 7
2060 -141 201 17 3 196 8
2070 42 181 16 3 203 8
2080 226 154 16 3 211 8
2090 54 128 15 3 203 8
2100 -117 96 15 3 195 7
* Provisional estimates
** Data from AIM model B2 marker scenario run

TOTAL GLOBAL EMISSIONS IPCC SRES B2 Scenario including natural sources*

CO2 [MtC] CH4 [MtCH4] SOx [MtS] N2O [MtN] CO [MtC] NOx [MtN]
1990 7065 481.00 91 11 449 48
2000 8927 490.74 92 12 477 54
2010 9926 517.40 86 12 495 58
2020 10246 535.16 76 12 493 63
2030 11167 546.33 70 12 510 70
2040 11334 533.56 66 12 473 74
2050 10989 520.78 59 12 494 75
2060 11665 513.83 56 12 471 77
2070 12021 506.88 52 12 462 76
2080 12792 499.56 50 12 454 82
2090 13329 491.86 49 12 434 86
2100 13821 484.17 48 12 416 85
*Natural sources include:
200 Tg CH4 (wetlands etc. IPCC 1995)
22 MtS (natural sources from IS92a)
9 MtN (N2O) (natural sources from IS92a)
30 TgC (CO) (oceans and wildfires from IS92a)
17 MtN (Nox) (lightning etc.from IS92a)

************************************
8/9/98 (from Wigley/Rapier

Dear all,

The emissions data sent out by Naki seem to me to be deficient
for a number of reasons …

(1) CO2 emissions need to be split into fossil and net
deforestation in order to do carbon cycle modeling.
(2) My crucial point about consistency with ‘observed’
emissions has been ignored.
(3) CH4 emissions in 1990 are grossly out of budget balance –
even worse that in the IS92 scenarios.
(4) 1990 SOx emissions are too low compared with Steve Smith’s
corrected GEAI data.
(5) Global SOx emissions are useless — it is essential to
have a global GRIDDED data set. This is what we have done
at NCAR. We are willing to make these data sets available
to modelers.

In addition, there were some scientific flaws in the letter from
Watson et al. For example (read the SAR!) it is not possible (and
not necessary!!) to devise a CO2 emissions scenarios from first
principles that will stabilize CO2 concentrations. The E-C link
depends on the carbon cycle model used — and I do not believe
that all of the emissions generating groups have the same model
(or that they have the Joos model in particular). What we did in
the SAR is start with the CONCENTRATION profile and derive the
emissions, which requires specifying a particular net deforestation
scenario. It is possible to do a similar inverse calculation to
what was done for the SAR with an energy-economics model — this
is what Steve Smith has done to derive ‘our’ stabilization cases.
I doubt that anyone else has done this — but perhaps I am
underestimating people.

Even if I am underestimating people, I can’t see how anyone
can have done this properly, since no-one has updated concentration
stabilization profiles (i.e., profiles that are consistent with
observations through the 1990s). Again, I’ve made the offer to
distribute these already.

As a final painfully obvious point, modelers DO NOT NEED CO2
emissions data for a stabilization case, since we already have
the concentrations! It is the concentrations that go into the
model!! The reason why an energy-economics model is needed in
such a case is in order to get consistent emissions for non-CO2
gases, especially SO2.

You might guess from the above that I was very disappointed by
the material distributed by Naki. Please think about the points
made above and try again. This is really important data and ‘we’
can’t afford to have it open to the elementary types of criticisms
raised here.

Constructively (albiet bluntly) yours,

Tom Wigley.

*************************************
8/9/98 (from Maria Noguer)

Dear scenarios subscribers,

After going through Wigley’s Emails regarding the starting point of the new
emission scenarios (i.e., they will still begin in 1990 and not use observed
emissions for the 1990s), we would like to propose the following to the
modellers:

1) As Naki said, the emissions will be available on the web-site in early
August. We should all first study them and consider the rest of the points
that
Wigley raised in his Email (24/07/98)

2) We should definitely take seriously the criticism that was raised during
the
SAR for using out-of-date emissions data that were wrong during the 1990s.

3) The use of incorrect 1990s emissions makes little difference for the
projected CO2 concentrations and hence for the model runs. Although this might
be the case we should do our best to avoid the same criticism that we had
during
SAR.

>From this last points there are to questions that we would like to raise to
the
modellers:

a) Should we adopt any kind of “fixing” before running the model
experiments as
Wigley suggests?

b) Should it be only be corrected in the final version of the emission
scenarios?

Please post your comments to the whole scenarios Group: scenarios@meto.gov.uk

Looking forward to hearing from all of you,

Regards,

Maria Noguer

******************************
9/7/98 (from John Mitchell)

CC Dave Griggs

Dear Naki,

Thanks for the information on sulphur emissions. I have a general concern
about the new scenarios in how they relate to previous scenarios. In
particular, if we chose B2 as our “standard” scenario, then the message we
appear to give is that CO2 emissions
are now expected to be some 30% (from 20Gt at 2100 in IS92a to 14Gt) lower.
This is likely to be ceased on in as an indication that yet again we are
exaggerating
the problem of GHG emission. Of course, if there is evidence that future
GHG emissions will be lower, that is fine, but I havenot seen a compelling
argument that they will be.

I realise that part of the problem is in the way previous scenarios were
generated. Nevertheless, we have to deal with the situation as it is and we
do not want to
mislead people. The large reductions in sulphur in B2 may mean that there
is little change in global mean temperature change at 2100 from Is92a- at
least if we be;ieve that currently there is a strong cooling due to the
indirect effect. Any thoughts on how to maintian continuity with the 1996
report?

With best wishes

John

**************************************
9/9/98 (from Hugh Pitcher/Mike Hulme)

Hugh Pitcher asked this contribution to be circulated to the scenarios email
group. Here it is:

____________________________________________________
Hi Mike,

As an internal constructor, I have concerns about GNP growth rates being much
too high, leading to per capita incomes in 2100 that are a factor of two to
three too high–implying impacts wiol be less of a problem. From a carbon
point of view, these high GNP levels are offset by high reductions in final
energy
demand, and high rates of decarbonization, leading to carbon scenarios that
are not too bad. I am working on a spreadsheet model that will allow a
quick and
dirty way to redress these issues. But the modeling groups have already
put in a lot of work, and are not likely to be willling to go back to
square one and
redo things. This is particularly an issue for compute intensive tools
such as message, image, and Maria.

see below for my reactions to the points you make.

Cheers,

hugh
—–Original Message—–
From: Mike Hulme [SMTP: xxx@uea.ac.uk]
Sent: Tuesday, September 15, 1998 4:23 PM
To: scenarios
Subject: WGI emissions/scenarios conference

> Dear All,
>
> Here are three comments on the questions raised by WGI TSU on 7 Sept.
> and by some of the other contributions to the discussion about scenarios for
> IPCC TAR. I am commenting from the perspective of a climate scenario
> constructor servicing the impacts research community:
>
> 1. The SRES Working Group have identified 4 Marker Scenarios (out of a
> much larger range, although these 4 largely capture the range). I think the
> choice is good. I do not see why some modelling centres should not be
> able to run all 4 emissions scenarios through their GCM. From an impacts
> perspective I believe this would be very desirable and would enable a
> fair range of climate change scenarios to be used in impacts work using
> direct GCM output (without the need for scaling). And if all four Markers
> could be run through more than one GCM (i.e., with different climate
> sensitivities) then impacts work would have an even better sample of the
> possible climate change space to analyse. These aspects of uncertainty
> seem to me to be critical for impacts people (and integrated assessors)
> to explore, to get us away from single number ‘answers’.

amen

> 2. If a single emissions scenario *has* to be adopted by some GCM
> groups, B2 seems to have the recommendation from Naki (and maybe SRES too
>- the storyline refers to it as ‘dynamics as usual’). I think there are
> probably good reasons why SO2 emissions fall so much in this storyline –
>regional rather than global solutions and the encouragement of environmental
> protection. The fact that the reduced C emissions relative to IS92a are
> offset by the big fall in SO2 emissions (the net global warming in B2 is
> actually slightly higher than IS92a if aerosol effects are included)
> should simply be seen as a reflection of a more carefully worked out
> storylinethan was the case with IS92a. I do not think it a good idea
(indeed, I
> think it would be a very *bad* idea) for GCM centres to mix-and-match
> elements of IS92 and SRES98 scenarios – the TAR should try and stick
> with the SRES stories and emissions wherever possible. The internal
> consistency in these storylines (and hopefully emissions) is important to
>maintain (especially later on for impacts work), and the thinking behind
the SRES
> scenarios is considerably better than was achieved in the IS92
> scenarios.

I agree about not mixing. the real issue is finding a good way to fill
in emissions that are not estimated by a given group. We may need an explicit
table that each group fills in that gives which sources they do estimate. see
response to question 4.

> 3. The problem of different Markers having different 1990 emissions
> values (and the fact that 1990s C emissions diverge from those observed) is
> more serious. By 2000 the four Markers range in C emissions from energy
> sources from 6.6GtC (B1) to 8.0 GtC (A1). Given where we are right now
> (about 6.7GtC in 1997) it seems daft to have such a range for only 2 years
> hence (as Tom Wigley has pointed out). For example, by the time TAR is
> published we will know that A1 C emissions for 2000 are too high by, say,
> 15%. Surely we need to impose a ‘fix’ on all 4 Markers to account for this.
> Such amendment may occur as a result of the SRES ‘open-process’, but
> this will take up to 12 months to be agreed and published. Should not
> someone (WGI or WGIII TSUs) impose a temporary solution now for climate
> modellers?

The problem is that different models use different baseline data sets,
and this is very expensive to redo. One approach is to adapt a common 1990
data set and then apply model based rates of change to get to predicted
levels.
This does not solve the year 2000 problem, or the year 2005 or 2010
problem. The
larger issue here is that most of the long term scenarios that are available
have economic growth rates that are implausibly high, and this was true before
the current financial crisis began. Good sceanrios for the short term require
very different kinds of tools than we are using for the long term
scenarios. I would be willing to vote for a uniform set of emissions
values for the year 2000 and then let the models diverge from there, based
on their growth rates. We
would still have to come to an agreement about what the economic activity and
emissions levels would be for the year 2000.

> Similarly, something needs to be done for CH4 and N20 1990 emissions.
> CH4 1990 emissions range from 281 to 481Tg in the 4 Markers (compared with
> 506Tg in IS92). Surely this range is not defendable. I think at the
> least we need some assurance from SRES that there has been some
> investigation into these differences and that they will withstand
scientific scrutiny
> in peer review. Again, maybe the open-process may lead to revisions, but
> what do climate modellers do in the meantime? [By the way, the
> difference in global warming by 2100 that the SRES CH4 and N2O scenarios
generates
> relative to those in IS92a is between 0.05 and 0.3degC – lower in all
> cases].

The issue here is that all the models do not do ag and land use
emissions, leading to lower values because these emissions are omitted.
Another issue that has recently arisen here is that animal manure is a
significant
source of n20–latest ipcc protocol on emissions–and is apt to grow rapidly.
this changes our understanding of the potential role of agriculture when it
comes to trying to stabilize climate.

Hugh

****************************************
To: Naki From: John Houghton
Rob Swart David Griggs
John Mitchell
Geoff Jenkins
Maria Noguer
cc. Scenarios list
Bert Metz
Jim McCarthy
Bob Watson

Subject: Use by modellers of SRES Scenarios in the TAR

We have been looking at the draft SRES scenarios with a view, in the first
place, to selecting a mid-range scenario to recommend to GCM modelling
groups and others for modelling comparisons in the TAR and to provide a
consistent storyline across the various Chapters and on through into the
Summary for Policymakers, as we did with IS92a in 1995 and BAU in 1990.
>From the four SRES scenarios presented B2 would seem to be the most obvious
candidate but this appears to us to present some difficulties
Clearly if we are looking for a mid-range scenario we cannot choose the
highest (A2) or the lowest (B1). If we assume that these two bound the
limit of plausible futures we should be looking for a scenario somewhere in
the
mid-range of these two. However, both A1 and B2 are considerably below the
mid-range. From the storylines given it would seem that B2 is intended to
be the “central future”. However, its CO2 emissions are low compared to the
middle of the range or IS92a. Its sulphur emissions are the lowest by far
of all the four scenarios, which seems a little strange.

We have very quickly (so please treat with extreme caution) run all four
scenarios through a simple climate model, results are attached as Excel
files for those who can read attachments and, for B2, while compared to
IS92a the lower CO2 emissions result in a reduction in forcing of about
1Wm-2 the fact that the sulphur emissions reduce to such an extent means
that this is compensated by the reduced sulphur forcing.
Please could we receive comments on the following as soon as possible:

1) Are any of your family of scenarios, other than the four marker
scenarios more representative as a mid-range scenarios to be used for our
purpose?
2) Why are the B2 sulphur emissions much lower than those in the other
scenarios?
3) Why are the 1990 methane emissions, and consequent future emissions, in
B2 so low compared to the other scenarios?
4) Are the CO2 and sulphur emissions of B2 sufficiently plausible and
internally consistent to represent a “central future”, which we can use for
our mid-range scenario for the TAR?
5) If B2 is not considered to be satisfactory for the purpose, and there
are no other alternatives, would it be sensible to use IS92a, with reduced
sulphur emissions?

Please comment as quickly as you can as the modelling groups need to get
working as soon as possible and we would like to be able to get the views
of the modelling community in time to feed into your next SRES drafting
meeting in a few weeks time.

Best wishes,

John, Dave, John, Geoff, Maria

********************************************
9/18/98 (from Maria Noguer)

Subject: Summary of Session 1 of the Emission Scenarios Conference

Session 1:
1. Analysis of the marker scenarios
1a. Which of the marker scenarios are going to be the ones that the AOGCM
will run? What, if any other scenarios should also be run? The Web address
where the new emission scenarios can be found is:
http://sres.ciesin.org/index.html)
1a.1 Marker A1
1a.2 Marker B1
1a.3 Marker A2
1a.4 Marker B2
1b. Concerns raised regarding these marker emission scenarios (at this
moment only about marker B2):
1b.1 Starting point of the emission scenarios – not using
observed emissions from 1990 (Should it be fixed?)
1b.2 CO2 emissions need to be split into fossil and net
deforestation to do carbon cycle modelling?
1b.3 CH4 emissions in 1990 out of budget balance?
1b.4 1990 SOx emissions too low?
1b.5 Need global gridded SOx emissions dataset
1b.6 2100 CO2 and SO2 values are too low

After analysing the 4 Marker scenarios posted on the SRES site these are
four of the most important points raised:

1. Incomplete information for some of the markers, hence difficult to
decide which one is more appropriate. Atmospheric chemistry modellers need
emissions by individual species.
QUESTION: Will SRES provide complete information in time?
QUESTION: How many modelling centres will be prepared to run all 4
markers?

2. CO2 emissions need to be specified in more detailed:
* energy-related
* non-energy related
* net deforestation
QUESTION: Will SRES provide this in time?

3. 1990 values still not consistent with observed values. Very
different values among the markers themselves. QUESTION: Should they be
adjusted by SRES or modelling group?

4. SO2 emissions not in a gridded form. GCM models need. QUESTION: Who
will provide this? How many gridded SO2 datasets are available at the
moment? Wigley’s, Rhode + Hansson’s?

Assuming that the SRES team will address points 1 and 2 (i.e. will provide
complete information and detailed specification of the CO2 emissions in
time, our recommendations are the following:

* Impose a “fix” on the 4 Markers to account for the differences in
the 1990 values (make them consistent with the observed data). One
possibility is to use the fix suggested by Wigley (Wigley, Nature 390,
1997): Use observed emissions to 1996 (as far as data is available),
linearly extrapolate these to 2000 (under the assumption that this is better
projection than the corresponding Marker projection) and then use Marker
changes from 2000.

* Use B2 as the “central-future” scenario (with modified and
consistent values for 1990 to 2000)
Use A2 as the high limit (with modified and consistent values for
1990 to 2000)
Use B1 as the low limit (with modified and consistent values for
1990 to 2000)
* Use SO2 gridded data from a “reliable source” consistent with the
global values given by each of the Markers.

Finally, we think it would be very useful for 1 or 2 GCM modellers, 1 or 2
atmospheric chemistry experts and 1 or 2 scenario development experts to
attend the next SRES full author meeting (7-9 October 1998 – Beijing,
China). In that meeting the provisional scenarios will be discussed hence it
will be appropriate to present the points raised here and to discuss the
needs and preferences of the GCM community.
Our suggestions would be:
GCM modellers: G Boer, J Mitchell, J Meehl?
Atmospheric chemistry: F Joos, S Smith?
Scenarios: M Hulme?

Are any of you able to attend the SRES meeting at such short notice? We
realise this may not seem like a high priority but we believe the scenarios
issue is critical for the TAR and if we can resolve it in this way it will
be well worth the investment in time.

Thank you very much for all your inputs into this Conference, we hope it has
been a useful exercise. Please see actions bellow, noting that there is a
degree of urgency. At the Initial Lead Authors meeting for WGI TAR (30
Nov-2Dec 1998, Paris) we will continue the discussion on this Agenda item,
hopefully with inputs from the results of the SRES meeting.

David Griggs and Maria Noguer
IPCC WGI Technical Support Unit

Actions:

1. SRES (Naki) to inform the group as soon as possible, if, and, by when,
the SRES scenarios can be made compliant with points 1 and 2 above, and if
SRES can make the adjustments necessary in point 3.

2. Modelling group to inform the group if they are prepared to run scenario
B2 as the “central future” and B1 and A2 as the “low and “high”,
respectively, once adjusted.

3. Those groups with a sulphur model to offer to provide sulphur loadings
for those GCM which require it.

4. SRES and others to inform the group if they can provide SO2 gridded
datasets.

5. GCM, chemistry and scenario modellers to agree on who should attend the
SRES meeting (7-8 Oct, 1998).

**********************************************
9/22/98 (from Maria Noguer)
Dear scenario subscriber,

Many thanks to those of you who send comments regarding Session I (Analysis
of the marker scenarios). A summary of that Session will follow shortly.

This Email is just to introduce the second Session of this Email Conference:

Agenda item 2: 21 Sep – 30 Sep, 1998

2. AOGCMs need concentrations of GHG as forcing (some models include sulphur
cycle and would prefer to specify emissions rather that concentrations)
2.1 Conversion from emissions to concentrations – who
will do that:
a) simple models?
b) authors of the chemistry chapter to provide
estimates of concentrations?

Please send your comments to the group (scenarios@meto.gov.uk) and we will
summarise the outcome at the end of the session.

Regards,

Maria Noguer

**********************************************
9/22/98 (from Steve Smith)

There are two sets of immediate issues in regard to the preliminary
scenarios: self-consistency and provision of proper output for use in GCM
models. The first can probably be addressed at the October SRES writing
team meeting, some of the issues will probably take a little more work.

I agree with Mike Hume that all scenarios should be adjusted (either by the
modeling groups or post-hoc) to agree with “best guess” values for 1990
emissions, consistent with gas budget balances. The SAR 1990 values could
be used except for cases where estimates have changed substantially. The
lead authors of the appropriate TAR chapter should be contacted to endorse
this approach (ideally before the October SRES working group meeting).

As Mike and Tom also emphasized, it is also very important that the year
2000 values are consistent with emissions to date. For the preliminary
scenarios the SRES working group may need to apply an ad-hoc correction to
the scenarios. The simplest solution would be to allow the scenarios to
diverse only after the year 2000.

2) The scenarios are not consistent with each other.

The major problem here is that not all modeling groups can calculate
emissions trajectories for all gases and all emissions sectors (the
scenarios on the web were not appropriately labeled to make this clear). At
the next working group meeting we should be able to evaluate these
differences and select a set of “filler” emissions trajectories for each
scenario and emissions source (agricultural methane, cement CO2, etc.) to
be added to modeled emissions which lack these sources.

Its difficult to predict how long this would take. If emissios for a
complete set of gases/sectors exists in aggregate among the modeling groups
represented on the SRES team then it might not take very long to produce a
preliminary set of complete scenarios.

3) Scenarios for some GHG’s have not been produced at all.

This will need to be discussed at the Oct SRES meeting.

Should scenarios for spatially heterogeneous gases (i.e., CO, VOX,
tropospheric ozone) also be produced? Is there a need for such scenarios?
Most modeling groups do not have the capability of producing scenarios for
these gases.

4) CO2 emissions need to be specified in more detail.

At minimum, we should report CO2 emissions as energy-related emissions,
non-energy emissions, and net deforestation for maximum flexibility as
input into carbon-cycle models. Note that the 1990 net deforestation
emission figure is determined from an inverse calculation.

5) GCM modeling groups need concentration scenarios.

Concentration results produced from the preliminary scenarios will not
necessarily be consistent with whatever calculations are performed for the
TAR, since it is possible that the lead authors may chose new central
values for some parameters. Probably the best approach is to follow the SAR
in converting emissions to concentrations for the well-mixed GHG’s. Either
the same models used there, or models that have been calibrated to those,
could be used to do this.

We should make sure that the final concentration scenarios are fully
consistent
with TAR WGI report.

6) SO2 emissions are not in the form required by GCM modelers.

a) For use in the few GCM’s that contain sulfur chemistry, SO2 emissions
must be provided in gridded form.

This can obviously be done, however it is a question of who should perform
the work! Most of the emissions modeling groups do not provide data in
gridded form at present (we have for our scenarios).

b) However, more seriously, most GCM’s cannot use SO2 emissions, but must
be provided with atmospheric sulfate loadings or radiative forcings.

This requires that the SO2 emissions be run through a model such as a GCM
containing sulfur chemistry, which can supply either of the above. With
respect to the preliminary scenarios, this seems rather problematic given
the pressure for results now!

As for the final scenarios, some thought should be given now by the TSU and
others about how this will be accomplished.

*******************************************
9/22/98 (from Colin Johnson)

I have compiled the following summary tables to aid comparisons between
the four new IPCC scenarios and with IS92a. A short description of the new
scenarios is give on the web site. Note that scenarios A1 and A2 have
variants, but the nes listed are the only information I was able to obtain
today from the web site.
Details for IS92a are from Pepper et al. (1992) – ‘Emission scenarios for
the IPCC An Update’. Information for 2020 from IS92a was obtained by
linear interpolation between 2000 and 2025.

A few comments: A2 has no biomass fuels, and B2 has no details of
land surface processes – see the methane emissions. It is impossible
to compare emission totals where these include natural processes as
we do not have the full details. For example, I am uncertain if biomass
burning emissions have been included. B2 has no CO, NOx or N2O emissions
specified yet.

Colin Johnson, Hadley Centre, 7-IX-98

1. Fossil Fuel CO2 in Gt/yr as [C].

Scenario 1990 2020 2050 2100
__________________________________________
A1B 6.0 12.1 16.0 13.1

A2.1 6.2 11.1 18.5 29.9

B1 6.1 7.5 9.0 5.7

B2 5.9 9.3 11.2 13.9

IS92a 6.0 10.0 13.2 19.8
__________________________________________

2. Primary Energy in EJ/yr, and fossil fuel fraction (%).

Scenario 1990 2020 2050 2100
__________________________________________
A1B 345 648 1204 2079
(81) (82) (60) (31)

A2.1 330 611 984 1589
(95) (94) (91) (81)

B1 348 475 680 820
(80) (78) (63) (31)

B2 351 567 869 1356
(82) (82) (70) (51)

IS92a 344 648 934 1453
(88) (85) (74) (64)
__________________________________________

3. Global population in millions.

Scenario 1990 2020 2050 2100
__________________________________________
A1B 5262 7493 8704 7056

A2.1 5263 8191 11296 15068

B1 5297 7767 8933 7239

B2 5262 7672 9367 10414

IS92a 5252 7972 10031 11312
__________________________________________

4. Primary Energy Use per Capita (GJ/yr).

Scenario 1990 2020 2050 2100
__________________________________________
A1B 66 86 138 295

A2.1 63 74 87 105

B1 66 61 76 113

B2 67 74 93 130

IS92a 65 80 93 128
__________________________________________

5. Methane Emission in Tg/yr.

Scenario 1990 2020 2050 2100
__________________________________________
A1B 281 366 338 274

A2.1 309 444 643 923

B1 429 495 543 478

B2 68 87 104 188

IS92a 506 636 785 917
__________________________________________

6. Sulphur Emissions in Tg/yr as [S].

Scenario 1990 2020 2050 2100
__________________________________________
A1B 69 102 64 24

A2.1 77 106 109 57

B1 71 43 53 31

B2 58 40 21 12

IS92a (all) 98 133 141 169
IS92a (energy+
industry) 73 109 151 144
__________________________________________

***********************************************
9/22/98 (from Fortunate Joos)

Dear Colleagues,

First, I would like to say that I appreciate all the tremendous work the
scenario group has done so far. I would like to congratulate the group to
their
progress. In the following, a few points are raised that may be unresolved.

For the TAR, we need to have emission scenarios
(1) for all relevant anthropogenic greenhous agents
(2) that include all relevant anthropogenic sources
(3) that are in agreement within uncertainties with emission
estimates provided in the SAR for 1990 and if possible
with more up to date estimates (e.g. numbers for fossil
fuel CO2 emissions are available up to 1996).
(4) that are in a form as needed by chemistry and carbon modellers to
convert emissions into concentrations.

>From the WWW site sres.ciesin.org it appears that only the RIVM-Image
model does provide (at least until now) emissions for the most important
greenhouse
gases.

‘Other CO2’, N2O, CFC/HFC, PFC, SF6, CO, NMVOC, NOx emissions are missing for
the IASA model.

CFC/HFC, PFC, SF6, NMVOC, emissions are missing for the EPA and NIES model.

Atmospheric chemistry modellers need emissions by individual species (e.g.
see Table 2.5 in SAR, p 97 ff). Is this information available?

In the SAR average anthropogenic CH4 sources were estimated to be in the
range 300-400 Tg(CH4)/yr for the 1980-90 decade. The IASA model yields an
emission of 67.9 (probably fossil fuel related only) and the NIES model of 281
Tg(CH4)/yr.

In the 1994 report, anthropogenic N20 emissions were estimated to be in the
range of 3.3.-7.7 TgN/yr again for the 1980 decade. The RIVM model yields for
1990 an emission of 10.5 TgN/yr while the NIES model yields 2.4 TgN/yr.

If using numbers outside the SAR range, we would need to have a sound
scientific explanation for the difference.

Confronted with this incomplete information, it is not possible for me to
suggest which one of the proposed scenarios should be used in TAR.

In this context, I am also wondering whether results for the 4 scenarios are
available for all models.

Carbon modelling:
——————
One does not necessarily need net emissions by land use changes in simple
models. A minimal requirement is that net emissions by land use changes are
included in the total emission estimate.

More complex biospheric model need information how individual grid cells are
affected by land use changes. Thus, a land use data base describing the
conversion between different types of ecosystems and managed land may be
produced.

Net carbon emissions may also be split into main categories such as fossil,
cement production, tropical and northern hemisphere land use changes.

The fossil fuel scenario data should in my opinion match the most recent
carbon emission figures to avoid any boring discussions and critics.

I hope this is useful.

With best regards,

Fortunat

******************************************
9/22/98 (from Peter Whetten)

Dear All,

This is a brief follow-up to Mike Hulme’s contribution of a few days
ago, where he suggested that modelling groups may well be happy to use
all four marker scenarios. I agree that this would be best, particularly
if it was done using GCMs with a range of sensitivities. In this
context, the group may be interested to know that CSIRO would be willing
to undertake AOGCM simulations for all four scenarios (once converted to
concentrations in an agreed manner) and that this could be undertaken
within a reasonable timetable. (However, there is still interest here
in the selection of a single scenario for use in ensemble runs.) I also
should note that clearing up inconsistencies between scenarios and
observed emissions over the period 1990-2000 is seen here as of vital
importance.

Peter Whetton
CSIRO Atmospheric Research
Private Bag No 1, Aspendale, Vic, 3195, Australia
Ph +61 3 9239 4535
Fax +61 3 9239 4444
Email peter.whetton@dar.csiro.au

**************************************************
9/24/98 (from Michael Prather)

to: IPCC/TAR scenarios working groups

from: Michael Prather, (Dieter Ehhalt, Ivar Isaksen)
IPCC/SAR (WGI-Ch.2) and IPCC/TAR (WGI-Ch.4)

re: Calculation of trace-gas RF’s for climate simulations

My apologies for being out of touch for the past 3 weeks during the
discussion of TAR scenarios. Those of us who prepared the non-CO2
trace-gas scenarios for IS92a in the SAR plan to likewise generate
trace-gas/RF scenarios for TAR. I am unsure of WGI-Ch.3’s (CO2) or Ch.5’s
(aerosols) plans, but we shall coordinate. There are two steps here:

Step-1: Generate the major forcing from B2 scenario. Limit
the RF to major gases:

CO2 – WGI-Ch.3 (Prentice) to map emissions to CO2 (ppm)

CH4 – We will implement simple linearized lifetime mmodel
as per SAR, but include NOx and CO emissions.
We need to check that 1990-1998 predictions match obs.
There is no signficant new value for current CH4
lifetime than the SAR

N2O – Probably just use SAR lifetime (fixed), again check
budget against current abundance and trends

HFC-125 -These two HFCs were the major ones in IS92.
HFC-134a We would use/recommend SAR lifetimes.

O3 – Here we have experience with IPCC/Aviation assessment
on 3-D modeling of tropospheric ozone (& RF) increase
with NOx and CO emissions.
Probably do stratospheric O3 (and CFCs) as in SAR or
recent 1998 WMO.

sulfate – WGI-Ch.5 (Penner) to map emissions onto regional RFs.
organics Are the projected changes in other aerosols large
enough for this stage? ?soot ?dust

THIS STEP IS URGENT, AND WE PLAN TO COMPLETE IN A FEW WEEKS.

Step-2: Calculate the trace-gas changes and RFs for a range of TAR
scenarios. This will require far more detail on emissions (and climate
change) than is now available
(e.g., regional emissions for NOx, speciation of hydrocarbons), and we see
this being developed with the SRES over the next months. We plan to (and
need to) include changes in natural and managed ecosystems and this may be
beyond SRES’s intent. We plan to run detailed 3-D chemical models from
seveal groups for several of the TAR scenarios, but this will need
additional details in the scenarios. THIS STEP IS NOT AS URGENT AS STEP-1,
WHICH MUST BE COMPLETED FIRST.

******************************************
9/24/98 (from Fortunate Joos)

Dear Colleagues,

Just two quick comments on the recent mails by David and Maria and Michael
Prather

>(David and Maria:) our recommendations are the following:

>* Impose a “fix” on the 4 Markers to account for the differences in
>the 1990 values (make them consistent with the observed data). One
>possibility is to use the fix suggested by Wigley (Wigley, Nature 390,
>1997): Use observed emissions to 1996 (as far as data is available),
>linearly extrapolate these to 2000 (under the assumption that this is better
>projection than the corresponding Marker projection) and then use Marker
>changes from 2000.

This fix is not big science and will have a marginal impact on
projected CO2 given the overall scenario uncertainties. E.g. it is not
really relevant whether emissions in 2100 are lets say 13.9 or 13.6
GtC/yr and we should not spend to much time on this issue. However, to
avoid a mess and annoying discussions and recalculations somebody,
e.g. the scenario group, must do this simple fix for all groups.

Presently only the values for the year 1990, 2020, 2050 and 2100 are
on the web site. Values for the other years e.g. similar to the table
provide by Naki for B2, should be made available for all scenarios.

>Finally we think it would be very useful for 1 or 2 GCM modellers, 1 or 2
>atmospheric chemistry experts and 1 or 2 scenario development experts to
>attend the next SRES full author meeting (7-9 October 1998 – Beijing,
>China). In that meeting the provisional scenarios will be discussed hence it
>will be appropriate to present the points raised here and to discuss the
>needs and preferences of the GCM community.
>Our suggestions would be:
>GCM modellers: G Boer, J Mitchell, J Meehl?
>Atmospheric chemistry: F Joos, S Smith?
>Scenarios: M Hulme?
>
>Are any of you able to attend the SRES meeting at such short notice? We
>realise this may not seem like a high priority but we believe the scenarios
>issue is critical for the TAR and if we can resolve it in this way it will
>be well worth the investment in time.

Sorry, but I do not see how I can make it to Beijing given all the
ongoing obligations here in Bern as well as next weeks Vienna IPCC meeting.

>(Michael:) Step-1: Generate the major forcing from B2 scenario. Limit
>the RF to major gases:
>
> CO2 – WGI-Ch.3 (Prentice) to map emissions to CO2 (ppm)
> ..

We are ready in Bern to project CO2 concentrations for all of the
Marker scenarios using

1) the Bern model as used in SAR

2) the Bern model as updated to include an energy balance model to
project global SST and mean surface air temperature as well as sea
level rise for prescribed climate sensitivities (dT2xCO2). SST is then
used in the calculation of surface water CO2 partial pressure. Also
included is sediment-ocean interaction. The temperature feedback on
sea water carbonate chemistry is important for long term projections.

3) the 2.5-d physical-biogeochemical model of Stocker et al and
Marchal et al. that allows us to study the interaction between the
carbon cycle and changing thermohaline circulation.

With best wishes, Fortunat

*********************************************************
Content-return: allowed
Date: Mon, 28 Sep 1998 09:28:17 +0100
From: “Noguer, Maria” <mnoguer@meto.gov.uk>
Subject: FW: A quick, late comment on Agenda item one
Sender: owner-scenarios@meto.gov.uk
To: “scenarios,” <scenarios@meto.gov.uk>

> ———-
> From: Tom Wigley
> Sent: Friday, September 25, 1998 10:47 pm
> To: Peter Whetton
> Cc: Noguer, Maria
> Subject: Re: A quick, late comment on Agenda item one
>
> At 10:48 AM 9/22/98 +1000, you wrote:
> >Dear All,
> >
> >This is a brief follow-up to Mike Hulme’s contribution of a few days
> >ago, where he suggested that modelling groups may well be happy to use
> >all four marker scenarios. I agree that this would be best, particularly
> >if it was done using GCMs with a range of sensitivities. In this
> >context, the group may be interested to know that CSIRO would be willing
> >to undertake AOGCM simulations for all four scenarios (once converted to
> >concentrations in an agreed manner) and that this could be undertaken
> >within a reasonable timetable. (However, there is still interest here
> >in the selection of a single scenario for use in ensemble runs.) I also
> >should note that clearing up inconsistencies between scenarios and
> >observed emissions over the period 1990-2000 is seen here as of vital
> >importance.
> >
> >Peter Whetton
> >
> >
> >Peter Whetton
> >CSIRO Atmospheric Research
> >Private Bag No 1, Aspendale, Vic, 3195, Australia
> >Ph +61 3 9239 4535
> >Fax +61 3 9239 4444
> >Email peter.whetton@dar.csiro.au
> >
>
> Peter,
>
> A fine offer, but I don’t think you can do these runs. To do the
> SO4, you need to have a full S cycle. Otherwise you have to
> use 4-D SO4 loadings, or an albedo proxy. For our collaborative
> work, using the ACACIA/NCAR scenarios (which are superior
> to what is on the IPCC table, because we thought of all the
> problems beforehand), we will be handing over the SO4 data
> for you to use. To get these data requires running our model,
> which has full S chemistry, out to 2100. For the IPCC scenarios,
> someone will have to do a similar full-chem run before you could
> run your model — and, if they did such a run, IPCC would already
> have what you were offering!
>
> There was an indication in an email from Prather that Penner might
> produce the SO4 loadings. I pointed out to him that she cannot do
> this because, to my knowledge, she does not have access to an
> appropriate coupled model. She might think it can be done with an
> equilibrium model, but this would be wrong. Think of 2050 as an
> example. To get the SO4 loadings with an MLO/AGCM requires
> getting the correct (or at least consistent) climate for 2050. To do
> this, in turn, requires using some artificial CO2 or CO2-equiv that
> would give an MLO/AGCM equilibrium climate response that simulated
> the response in 2050 of an OAGCM. In fact, to really do this ‘right’
> one would also have to ‘fake up’ the SO2 emissions! We have thought
> this issue through at great length here, and decided that there simply
> was no adequate MLO/AGCM-based ‘short cut’ to getting the SO4
> loadings — which is why we go the full-chem route.
>
> I presume you are going to China. If so, enjoy. I will be at the CMIP
> workshop on Oct 14,15 and will be at CSIRO on the 16th.
>
> Cheers, Tom.
>

Comments
  1. tallbloke says:

    In Naki’s followup email we get this:

    The next issue raised in the discussion is more substantial and much more
    difficult to deal with. Carbon dioxide emissions are indeed generally lower
    for a given level of development than in the IS92 and other “older”
    scenarios. A frequently cited example has been that of IS92a compared to
    the tentative “intermediate” or “central” marker scenario B2. By 2100, CO2
    emissions of all anthropogenic sources are about 20 GtC in IS92a, compared
    to 14 GtC in B2. This difference has a lot to do with new data on energy
    resource availability that have become available since IS92 (cf. the rel.
    chapter in SAR), a different role that technological change plays,
    structural transformations and a shift in the energy system from carbon
    intensive to less carbon intensive fuels. Such tendencies can also be
    observed in the literature that became available since IS92 and that is
    contained in the SRES scenario database. It is simply no longer possible to
    construct a central case of the type IS92a was. Central population
    trajectories and median GDP growth rates result in generally lower
    emissions across a range of models compared to IS92a. Clearly, one could
    construct a coal-intensive type of scenario that would indeed result in the
    range of about 20 GtC, however, this would be a mere reconstruction of
    IS92a. SRES includes these kind of scenarios as well (A1 variants and A2)
    and this kind of scenario already exists, namely IS92a.

    This is even more the case with sulfur emissions. You may recall that the
    1994 evaluation of the IS92 scenarios concluded that sulfur emission trends
    are inappropriate, as IS92 did not take the effects of recent tightened
    sulfur legislation in Europe and North America into account. Equally, a
    number of new studies on the adverse impacts of unabated, high sulfur
    emissions scenarios have become available since the days of IS92. As a
    result, scenarios of unabated sulfur emissions no longer appear credible
    for long-term time horizons. A detailed literature review has been
    performed within SRES on this topic. The conclusion is that sulfur
    emissions in the range between 140 to 230 MtS by 2100 like IS92a,b,e,f are
    characteristic of “no-sulfur control” scenarios available in the most
    recent literature. Conversely, the range spanned by sulfur control
    scenarios is between 20 to 120 MtS by 2100.

    Most of the scenarios that are based on some degree of sustainable
    development (B1, B2, and some A1 variants in their own high-tech way),
    envisage active sulfur abatement (because of environmental and health
    reasons other than
    climate change). The scenarios also assume continuation of current policies
    and measures, together with a kind of “graduation clause” whereby countries
    that reach high degree of affluence do not tolerate higher degrees of local
    and regional environmental degradation than countries with similar degree
    of affluence do today. In addition, some of the traditional sources of
    sulfur simply are eliminated for reasons other than “sulfur emissions”.
    Some scenarios require production of synfuels where sulfur-removal is
    process inherent. In most scenarios there is a shift from sulfur rich to
    sulfur poor coals and from coal in general to natural gas and renewable
    sources of energy. All of these changes result in substantially lower
    sulfur emissions.

    The SRES marker scenarios range between 40 to 110 MtS by 2050 and between
    20 to 60 MtS by 2100. Emissions in the scenarios B1 and B2 are very
    similar, because both storylines put a lot of emphasis on local and
    regional environmental quality, and hence both scenarios assume similar
    degrees of sulfur reduction efforts. (The differences between the scenarios
    reported on the SRES website are a reporting misspecification, as for B2
    only energy-related sulfur emissions were reported, but not other
    industrial sources. This has been fixed in the meantime and the website
    will be changed after our meeting next week.) We will also revisit the
    issue of the relative ranking and differentiation between scenarios next week.

    Concerning gridded sulfur emission data the SRES team is currently not in a
    position to provide such a data set. Sulfur emission data are available for
    between 10 to 20 world regions from the SRES models. Both Steve Smith and
    Michael Schlesinger will attend our meeting next week and I hope that they
    can provide suggestions of how to practically deal with this request.
    Michael has already converted the sulfur emissions from all SRES marker
    scenarios in to regionally gridded scale.

    Many thanks for all your inputs. I look forward to a continued fruitful
    exchange to make the SRES work as useful as possible.

    With best regards, Naki

  2. Ripper says:

    And that is why the IBUKI satellite measurements are completely at odds with what we were told was going to happen.

    http://www.jaxa.jp/projects/sat/gosat/index_e.html

  3. Roger Andrews says:

    The end-product of all this back-and-forth is summarized in the IPCC TAR Figure 17:


    It would have saved a lot of time if the authors had admitted up front that they really hadn’t the faintest idea what emissions were going to do over the next 100 years.

  4. michael hart says:

    There they were, back in the heady days of 1998, busy the saving the world, and probably more besides.

    Imagine their reaction if some rude outsider had been allowed to intrude and say “In 15 years time human CO2 emissions will have continued rising inexorably, your global mean temperature will actually be lower than now, and the Met Office will be surreptitiously publishing downward predictions on Christmas Eve in the hope that nobody notices. Do you have a plan B?”

    “Sorry” would be a good start for plan B.