Dear Mr Beacon

Thank you for your email and your patience in waiting for the answers.

As the questions relate to Lord Turner’s appearance of 2nd July 2008, most of the questions 
will have already been covered by our advice to Parliament contained in our reports from 
December 2008 available >here< and the recently published step change report available >here<.

Q1.1: Our 2008 report did indeed emphasise that observed decreases in Arctic summer sea ice 
      during 2007 and 2008 have been at the very top end of what climate models have suggested. 
      It is important to note however that sea ice, along with many other aspects of the climate 
      system, shows year-on-year variability due to chaotic weather patterns. As yet it is still 
      unclear to what extent this decrease is the start of a more rapid decline, and how much is 
      a short-term result of natural variability from which there will be some recovery (although 
      this would clearly still be part of a longer-term declining trend). More information can be 
      found here: http://earthobservatory.nasa.gov/Features/SeaIce/page3.php. In general, periods 
      of at least 30 years are used to identify climate trends, in order to filter out the 
      influence of natural variability.

      The accuracy and reliability of climate models and their predictions are tested using a 
      large number of real-world observations or ‘milestones’. These include ability to reproduce 
      observed trends in seasonal surface temperatures, precipitation and sea level pressure, as 
      well as natural patterns such as El Nino. More information is available in the IPCC Working 
      Group 1 4th Assessment (AR4) Chapter 8, here: http://ipcc-wg1.ucar.edu/wg1/wg1-report.html.

Q1.2: There are a number of world-leading models which are used in assessments of climate, and 
      the research teams behind each of them continue to work on improvements. Whilst a list of 
      models participating in IPCC AR4 can be found at 
      http://www-pcmdi.llnl.gov/ipcc/model_documentation/ipcc_model_documentation.php, 
      the CCC is not in direct communication with all of them. We recommend that you contact 
      these groups directly to find out about their latest improvements.

Q2.1: The CCC recognises that there is uncertainty in various parameters of the climate system 
      that are important for projecting future climate change. As a result we took a risk-based 
      approach to setting targets in the 2008 report. Climate modelling work carried out by the 
      Met Office identified probabilistic ranges of warming for different future emissions 
      pathways. These ranges reflect the fact that some processes (for instance carbon cycle 
      feedbacks or climate sensitivity) could be stronger than simply the ‘best guess’ or 
      ‘central estimate’ values in the literature (see the Technical Appendix to Chapter 1 
      http://www.theccc.org.uk/other_docs/Ch1%20technical%20appendix%20-%20projecting%20global%20emissions,%20concentrations%20and%20temperatures.pdf 
      for more details). The CCC’s recommended emission targets were based on an emission 
      trajectory which gives a 50/50 probability of staying close to 2 degrees this century, 
      whilst also minimising the probability of an extremely dangerous 4 degrees increase, 
      based on the best current information.

      Beyond accounting for the possibility of stronger feedbacks in this way, it is unclear 
      what you mean by an ‘emergency stop’. Where there any particular suggestions you had 
      in mind?

Q3.1: The CCC is unable to comment on unpublished work. The UK carbon budgets are on a 
      ‘production’ basis, i.e. they refer to gases emitted directly by the UK net of any carbon 
      credit trading. UK emissions on this basis were slightly under 11MtCO2e per capita in 2006 
      excluding international aviation and shipping (IAS), and slightly over 11MtCO2e including 
      IAS on a bunker fuels basis. We have not attempted to measure the UK’s emissions on a 
      ‘consumption’ basis.

Q4.1: Policy options are for the relevant Government departments. The CCC reports to Parliament 
      and has given its evidence to various Parliamentary Committees.

Our advice to date has not covered educational policies. The Committee’s role is set out in the 
      Climate Change Act (2008), and our advice under that remit is given directly to Parliament 
      as a published document.

5.1 Will the CCC investigate whether the greenhouse gases emitted as a result of building 
    construction should be estimated in the planning process? Ute

    To date, the CCC has focused its analysis on emissions from existing buildings as new built 
    emissions account for a very small percentage of the total in the first three budget periods. 
    As we look at future budget periods, we will consider the role of new built, including the 
    issue of life-cycle emissions.

Q5.2: Tall buildings create more greenhouse gases per square metre of floor area than low 
      buildings. Will the CCC ask for this to be taken into account in government planning 
      policy? Ute

      This is not something we have considered as we have done very little analysis on 
      new-built to date.

Q6.1: Yes we can, in areas where planning policy has an impact on carbon budgets. We consider 
      various planning policy measures in the transport chapter of our October 09 progress report.

Q6.2: We have not considered the issue of personal carbon rationing and currently have no plans 
      to do so.

Q6.3: The CCC is an advisory body; changes to legislation can only be done by Parliament.

Q6.4: If our future analysis on new built housing shows that this is an important issue, we will 
      consider it.

Q7.1: It is not in the remit of the CCC to investigate access to information. You may wish to 
      look at the website of the information commissioner. www.ico.gov.uk 

Q8.1: There is recent research (two papers on this subject are here 
      http://www.cccma.ec.gc.ca/papers/ngillett/PDFS/nature08047.pdf and here 
      http://www.iac.ethz.ch/people/knuttir/papers/allen09nat.pdf) suggesting that the specific 
      timing of CO2 emissions is less important than the overall total amount of CO2 that is 
      emitted over time. Including the effect of carbon cycle feedbacks in the climate system, 
      these studies imply that a gigatonne of CO2 emitted in 20 years’ time would have the same 
      result (in terms of temperature increase) as a gigatonne emitted now.

Q8.2: We have not yet set our work plans for our future progress and budget reports. We will 
      consider those issues relevant to providing our advice as required under the Climate Change 
      Act and requests made under the powers of the Act.

Q9.1: We have not yet set our work plans for our future progress and budget reports.

Q9.2: The CCC’s ‘Building a Low Carbon Economy’ Report deals with burden-sharing methodologies 
      in chapter 1.

Q10.1: We have not covered this issue explicitly in our reporting to date.

Q10.2: This event took place before the questions were sent.

Q11.1 & Q11.2: Development aid is not covered in the Climate Change act.

Q12.1:  There is no plans for any specific work to be undertaken in relation to the theory of 
        backfire or rebound effects in respect of household energy efficiency.  However this is 
        an area that the CCC is aware of.

Q13:  You are correct that natural release of methane as temperatures rise is an issue of concern, 
      and is one that we highlighted specifically in Chapter 1 of our 2008 report. Recent estimates 
      suggest that it will cause additional local warming, perhaps similar to the level brought 
      about by methane emissions from human activities 
      (see http://www.agu.org/pubs/crossref/2004/2004GL020919.shtml), but there is no science to 
      our knowledge which implies this will cause a ‘runaway’ feedback from which temperatures 
      never stabilise. The CCC relies on peer reviewed publications in its analysis, and is keeping 
      a close eye on emerging findings about natural methane release.

      In terms of ‘dangerous’ climate change, two degrees is widely adopted as the threshold after 
      which dangerous climate change occurs. This is of course a value judgment, based on the 
      scientific evidence. As explained above the CCC took a risk-based approach to setting a 
      climate target which reflects the importance of two degrees and also the scientific 
      uncertainty in projecting future climate. Scientific consensus is that it will be possible 
      to avoid this level of climate change, if the world acts quickly to curb emissions. The 
      emissions targets recommended by the CCC are designed to ensure that the UK fully plays its 
      part in meeting the challenge.

I replied on the 2nd November 2009

To Enquiries@theccc.gsi.org.uk

Thank you for your reply. Although this is over a year since I originally asked the questions, 
I feel that your answers, though limited by your constitutional postion, are knowledgeable 
and seriously meant. I will make a few preliminary comments:

You say:

"Q8.1: There is recent research (two papers on this subject are here 
http://www.cccma.ec.gc.ca/papers/ngillett/PDFS/nature08047.pdf and 
here http://www.iac.ethz.ch/people/knuttir/papers/allen09nat.pdf) 
suggesting that the specific timing of CO2 emissions is less 
important than the overall total amount of CO2 that is emitted 
over time. Including the effect of carbon cycle feedbacks in the 
climate system, these studies imply that a gigatonne of CO2 emitted 
in 20 years time would have the same result (in terms of temperature 
increase) as a gigatonne emitted now."

I am aware, in general terms, of these arguments. In "normal" circumtances, carbon dioxide 
stays in the atmosphere a long time. What is curently emitted may be large but will not 
increase the concentration in the atmosphere by large percentage. But this does not 
account for the danger of a climate "tipping point" being reached. The research you 
report - that specific timing of CO2 emissions is less important than the overall total 
amount of CO2 that is emitted over time - assumes that no climate tipping points are near. 
If such possibilities are serious we may consider we taking risks all the time CO2 
has an atmospheric concentration greater than 350 ppm. Have you any evidence which excludes 
these possibilities? 

Put another way "How low are the probabilities you assign to climate feedbacks such as 
large releases of methane from shallow sea in the Arctic or the Amazon rainforest drying?

Please comment on the following:


It's methane that worries me - it's a strong greenhouse gas and a big danger. It probably 
caused mass extinctions in the past.

There's lots of methane under oceans - some in seas near the North Pole. This is beginning 
to bubble up as the Arctic warms. 

The warming also uncovers ancient plant matter that rots to produce methane and carbon dioxide.

Scientists can't estimate how big these effects will be - they have only just started. Some 
say they are worried, some say very worried. 

But methane could be an opportunity. It is cleared from the atmosphere in about 12 years so 
stopping new emissions would reduce the pace of global warming quickly. The big human sources 
are coalmining, paddy fields, grass burning and livestock.

A recent report by World Bank staff says livestock is half of man-made global warming. Defra 
funded research shows that beef and lamb are particularly bad. 


I feel we in the UK should create environmentally friendly lifestyles that the rest of the 
world would be eager to follow. Look at http://renewalcities.org to see an example of the 
approch I currently favour.

I will contact you later about an "emergency stop". 


Geoff Beacon

I received the following reply on the 2nd Novamber 2009

Geoff

Thank you for your email. On the subject of methane and climate feedback; we do not assign 
probabilities to methane release because we do not yet know enough about these processes 
to include them in our models projections. We do however draw attention to this in our 
'Building a Low Carbon Economy' Report - December 2008.

We do discuss the opportunities to reduce UK methane emissions in chapter 9 of the same report.

Kind regards

Mark    

If I had had the energy, I would have argued that methane wasn't the only worrying feedback.
I did receive a very helpful email from John Mitchell, Principal Research Fellow at the Met
Office in March 2012, which confirmed my worries.

  Hi Geoff
 
I apologise for not answering earlier - I now work part time.
 
Based on help from my colleagues
 
 
          1.  reduced sea ice cover reflecting less of the sun's heat back out to space,

          2.  changing ocean circulation patterns
                
1,2 are in most models and have been for years 


          3.  less carbon dioxide absorption by the oceans

          4.  increased soil respiration

3,4 are in most carbon cycle models and fairly well established. There are a good number 
of such models in the current IPCC assessment


          5.  more forest fires
          
5 we don't do yet, but could be important for changing ecosystems response to climate. 

 

          6.  melting permafrost emissions (6a CO2, 6b CH4)
          
6a/b we don't have in the GCM, but have some simple modelling of. Too early to show any 
results yet, but we plan to publish later this year. Bottom line is that both CH4 and 
CO2 will be released as permafrost thaws. The magnitude is uncertain, but likely to be 
significant.

 

          7.  increased decomposition of wetlands
          
7,  we have in HadGEM2 but didn't enable as a fully coupled feedback, but we can diagnose 
changes in wetland extent and CH4 emissions

 
I would add that although these things may be important, they are not always easy to quantify, 
model, initialize  and validate, especially 5-7. That is why is taking time ot implement them. 
 
John