Climate science and UK Government and political institutions

[GeoffBeacon]

I have received this letter from Greg Barker, the UK Climate Change Minister, via my MP. Comments welcome.

Thank you for your letter dated 25 October to Ed Davey, enclosing  correspondence from your constituent Mr Geoff Beacon about missing feedbacks in climate models and a video entitled 'Last Hours'.  I am replying as this matter falls within my portfolio.

Scientists and policymakers alike are well aware that there are missing feedbacks in the current generation of Earth system climate models. However, most of these feedbacks are considered to have potential effects over century-long time scales and cannot be reliably quantified at present. There is, though, on-going research work by many institutes, including the Met Office Hadley Centre, to develop better understanding of these feedbacks and thus be able to incorporate them the latest climate models.

The target limit of 2°C above pre-industrial for future global warming, as advocated by the UK and other parties to the United Nations Framework Convention on Climate Change, is considered likely to minimise future risks of any climate change escalation resulting from feedbacks in the climate system such as large-scale release of methane. Achieving the 2°C limit will require major and sustained cuts in global greenhouse gas emissions.

On the particular issue of a climate feedback from thawing Arctic, the Intergovermental Panel on Climate Change’s (lPCC) Fifth Assessment Report (AR5) report on the physical science  released in September 2013, concludes that this is likely to be a relatively slow  feedback that should be considered over century time scales (Chapter 6, p76) In  case of ocean methane hydrates, the time scales are of the order of centuries to millennia   (Chapter 6,  p76). For this century, current models suggest carbon models from thawing permafrost is likely to be relatively modest, even for the IPCC's worst case (RCP8.5) representative concentrations pathway (Chapter 6, p56).

Your constituent also refers to a newspaper report on Alaskan permafrost degradation. I understand from science experts in my Department, that temperatures in Alaska were quite  stable up to the mid-1970s, then rapidly increased (by about 2.2°C) and remained stable at that level until about 2006, when they started to fall quickly. These temperature changes may be due to the influence of changes in the Pacific Decadal Oscillation (PDO) cycle, superimposed on the warming effect from rising greenhouse gas concentrations.

 “Last Hours” is video presentation speculating that further anthropogenic global warming of about 5°C may lead the world towards a future mass extinction, possibly analogous to mass extinction that occurred 250 million years ago when a similar rise in temperature is to have occurred. The trigger for this future extinction is speculated to be massive releases of methane from frozen hydrate deposits in the ocean and permafrost in the tundra. It further claims this process is already being observed in the Arctic. However, further studies suggest other factors were responsible for the late Permian mass extinction when conditions on Earth were very different to those at present. Also, the AR5 report concludes that atmospheric methane concentration observations do not currently show any significant increase over the Arctic region (Chapter 6, p77) and that a 5°C  represent the top end of the projected temperature range for a ‘high emissions'  representative concentration pathway (RCP8.5).

 In conclusion, the UK Government fully recognises the need for urgent global action to based on the best available scientific evidence and the UK is at the forefront of efforts to secure a global deal on emissions reductions that minimise the risks of dangerous climate change in the future.

I hope this information was useful.

Yours ever,


Gregory Barker

[AbruptSLR]

GeoffBeacon,

Thanks for posting this letter summarizing the political/institutional position of climate science in the UK.  While: (a) it is difficult to change institutional positions on such points; and (b) I do not have time to provide much support in clarifying the weaknesses of such institutional positions; nevertheless, if you care to respond to this letter you could try reviewing some of the references on this topic that I have posted in the ASIF/Antarctic folder, here:

http://forum.arctic-sea-ice.net/index.php/topic,41.0.html

While this thread focuses on feedback mechanisms that may accelerate sea level rise contributions from Antarctica; nevertheless, you could extra support information (to indicate the weakness of the institutional position), for considerations including the following:
-  The measured Black Carbon, BC, feedback/emissions are stronger than that assumed by RCP 8.5.
-  US Government representatives in the IPCC climate change discussions have publically stated that they do not believe that it is feasible to achieve the goal of limiting global temperature increase to 2 degrees C.
- With increasing methane emissions (such as from shale gas) the Global Warming Potential, GWP, of methane will likely increase well above the value of 34 times CO2 (over a century), assumed by AR5.
- China has announced a $275 billion dollar plan to clean-up their air pollution (aerosol concentration); which when implemented will decrease the albedo over China.
- The documented growth of vegetation in the Arctic region will continue to decrease the albedo of the Arctic region.
-  The documented increase in wildfires will be a more positive feedback factor, than assumed.
-  The documented increase in the number of earthworms will accelerate CO2 emissions from soil organic carbon (SOC) stockpiles.
- Due to the acidification of the oceans the sulfur content of the atmosphere will increase.
-  Increases in the hydrological cycle (including water vapor invasion of the stratosphere) will be a more positive feedback factor than assumed.
- Most of the feedback factors used in the global circulation models, GCMs, are calibrated based on paleo-evidence from radiative driven warming, while current global warming is due to increasing GHG concentrations, which have more positive feedback factors than the paleo feedback factors.
- Both changes in the terrestrial and ocean CO2 sinks should absorb less CO2 in the future than previously assumed.
- The ENSO oscillation is projected to become more intense in the future, which should accelerate global warming.

Please review the link that I provided for references and for other mechanisms, not mentioned here.