#ExClimate

Jan 2018

I have enrolled on "Climate Change:The Science" - run by the University of Exeter.
I will be using the course content to refresh/extend my understanding of the science following the course I took part in last year, and the discussion threads to interact with other learners.


Week 2

A quick recap on what I have learnt this week.
(Under construction)

The videos and course material is familiar from last year but despite this a recap was very worthwhile.
Following up things that have been said in comments has also been extremely helpful in furthering my understanding in several areas which include:

Measurement of CO2 in the atmosphere including historical measurement and how scientists ascertain that the recent rise is primarily due to burning fossil fuels, the stability of the Holocene and the hockey stick graph, the reaction of corals to climate change

 I've copied my comments on these subject areas below

"Liquid" measurement of CO2 - Beck (2006):
I presume that you are referring to the Beck paper from 2006 when you talk about levels of CO2 reaching 400ppm in the last 150 years?
I did some research on this when you first mentioned it as it intrigued me. Unfortunately I couldn't turn up a whole lot which is perhaps significant in itself.
What I did find is here
here
in which Eli concludes "I am simply going to quote Keeling's Epilog which explains why Beck's analysis is wrong. "
and here
"the accuracy of the wet methods was more than 1%, more often like 3%, which is somewhere between 3 and 10 ppm. The infrared absorption method introduced by Keeling had an accuracy of a part in four thousand"
Interesting, but my curiosity is satisfied. Unless you have some more links/references?
btw I do try to research comments I find interesting, but it can be hard to do so without links to the papers/research etc that are being discussed - especially if they are outside mainstream science


Proving recent CO2 increase is due to burning fossil fuels:
"A new study has confirmed the existence of a positive feedback operating in climate change whereby warming itself may amplify a rise in greenhouse gases resulting in additional warming." 
https://phys.org/news/2015-03-evidence-positive-feedback-climate.html

"Professor Tim Lenton from the University of Exeter said: "Our new results confirm the prediction of positive feedback from the climate models, the big difference is that now we have independent data based evidence for it."
Other resources about historical levels of CO2, and how the chemical composition of naturally produced CO2 differs from that produced by burning fossil fuels, which you might find interesting:

Alternative theories (Salby):
I am aware of Salby's theory and have read several versions of it's rebuttal. There's a vast amount of evidence that the rise of CO2 in the atmosphere in recent years is primarily due to burning fossil fuel.
https://andthentheresphysics.wordpress.com/2013/11/14/salby-comment-1/ - lots of interesting discussion in the comments. (from 2013)
https://andthentheresphysics.wordpress.com/2016/08/10/murry-salby-in-london/(following Salby's more recent talk in London - article contains numerous links to further resources on the subject).
and here:
https://www.skepticalscience.com/Murry-Salby-CO2-rise-natural.htm with extensive discussion in the comments section.
Salby does seem to be rather a colourful character :
https://www.desmogblog.com/2013/07/12/murry-salby-sacked-australian-university--banned-national-science-foundation
"A climate sceptic professor fired from his Australian university for alleged policy breaches had previously been banned for three years from accessing US taxpayer-funded science research money."

Why the relationship between emissions and measured CO isn't direct:
In my understanding there isn't a straightforward, direct relationship between human emissions and how much CO2 is in the atmosphere. Carbon dioxide levels also vary according to natural feedbacks/forcings and the difference between levels emitted by sources and absorbed by sinks as part of the carbon cycle.
It appears that a calculation has to be done to directly compare anthropogenic emisions to the levels of CO2 in the atmosphere. However :
"When CO2 emissions are compared directly to CO2 levels, there is a strong correlation in the long term trends. This is independently confirmed by carbon isotopes which find the falling ratio of C13/C12 correlates well with fossil fuel emissions. "
The stability of the Holocene and the controversy over the Little Ice Age and Medieval Warm Period with regard to the "hockey stick" graph: (Incomplete - more work needed).
An interesting question about the Holocene. I've found this resource which seems to provide some of the information you're looking for?
The impact of global warming on corals (via a comment about Ridd) 
(under construction).
I've also been reminded of Graham Redfearns podcasts - which include two about corals and discovered the blog by Geoff M Price - Pressing Wax  

Week 1

Anthropgenic Drivers in the Climate System.

I've chosen the greenhouse gas CO2 to investigate further.

I am particularly interested in the 3rd question - the part CO2 plays in climate change feedback processes. I've also been looking at the role naturally present CO2 has played in shaping the climate in the past (and still plays today). It is important that we are able to see how human produced CO2 is causing the global warming we are experiencing today, and are able to "tease that out" from any effects due to naturally occurring CO2.

I have discovered that in the past carbon dioxide (and other greenhouse gases) acted primarily as a feedback to natural forcing, such as changes in the earth's orbit causing temperature changes due to varying amounts of heat from the sun hitting the earth's surface. This explains why an examination of past relationships between carbon dioxide in the atmosphere and changes in the earth's climate do not always show that an increase in carbon dioxide comes before warming. This is explained in a useful article I found. It is an important point to be aware of when discussing climate change with sceptics who often bring up perceived historical "discrepancies" in the causal relationship between changing concentrations of CO2 in the atmosphere and global climate.

In addition it has been discovered that "warming itself may amplify a rise in greenhouse gases resulting in additional warming." (Study).

Sceptical science has addition articles on the subject of CO2 and feedback. Here and here.

Another interesting aspect to the part carbon dioxide plays in climate change is the fact that scientists can determine how much of it is coming from naturally occurring processes and how much is coming from humans burning fossil fuels. The CO2 that comes from burning fossil fuels has a distinctive composition -

"Confirmation that rising carbon dioxide levels are due to human activity comes from analysing the types of carbon found in the air. The carbon atom has several different isotopes (eg - different number of neutrons). Carbon 12 has 6 neutrons, carbon 13 has 7 neutrons. Plants have a lower C13/C12 ratio than in the atmosphere. If rising atmospheric CO2 comes fossil fuels, the C13/C12 should be falling. Indeed this is what is occuring (Ghosh 2003) and the trend correlates with the trend in global emissions." Skeptical Science John Cook 2010.
"Scientists also can distinguish between CO2 molecules that are emitted naturally by plants and animals and those that result from the burning of fossil fuels. Carbon molecules from different sources have different numbers of neutrons in their nuclei; these different versions of molecules are called isotopes. Carbon isotopes derived from burning fossil fuels and deforestation are lighter than those from other sources. Scientists measuring carbon in the atmosphere can see that lighter carbon molecules are increasing, corresponding to the rise in fossil fuel emissions." State of The Planet. Renne Cho 2017

This is all very interesting stuff along with the issue of climate sensitivity - how big an effect on global temperature is the increase in CO2 in the atmosphere expected to have. More reading required. 

Sources:
https://phys.org/news/2015-03-evidence-positive-feedback-climate.html. University of Exeter 2015

https://www.yaleclimateconnections.org/2007/10/common-climate-misconceptions-co2-as-a-feedback-and-forcing-in-the-climate-system/. Zeke Hausfath 2007

https://www.theguardian.com/science/2018/jan/18/worst-case-global-warming-scenarios-not-credible-says-study

Week 1 - Useful links -
https://eos.org/opinions/taking-the-pulse-of-the-planet
https://oyc.yale.edu/geology-and-geophysics/gg-140

Week 1 - Reflection Questions 
My answers to the reflection questions are at the bottom of the page in the entry for Feb 2017.

Week 1 - Further Notes:

I need to some work on understanding the physics involved in the greenhouse/blanket effect in more depth and how indicators of greenhouse gas involvement can be used to "tease out" anthropogenic warming from natural variation. The issue of our ability (or not) to be able to quantify natural variation seems to be one of the mainstays of contrarian argument.

Climate Change - Challenges and Solutions 2017


This is where I will be posting some of my responses to, and thoughts on, the FutureLearn Course on Climate Change - Challenges and Solutions from the University of Exeter.

Student Blogs

Weeks 4/5 - Modelling, Ice and the Self Taught Expert (Key links and some thoughts)

Week 4

Climate modelling -

Great podcast which also covers current situation with Antartica:

DIY climate modelling

Also -  key work being on "attrition" - i.e. how specific weather events can be statistically linked to climate change  - recent study by Dr Otto discussed here:

I was interested in looking at the question about how recent temperatures reflect the predictions of climate models and found this article:
I have also seen this tweet published by Richard Betts (Professor of Climate Impacts, University of Exeter & Met Office Hadley Centre. )


  
I have learned about the importance of the language we use when communicating about climate change - there was quite a heated discussion regarding the use of word "denier" in the comments. Personally when I call someone a denier it is because that is what they do - a la James Delingpole, it does not have any other connotations. I think that goes for most of us.
Geoengineering - nice, but still a pipe dream, let's get on and persuade the politicians to actually do something about emissions. 
  
Week 5 

Key links - Liam's blog on ice flow controls.
David Barber's TED talk 

Discussion Point


I am finding that a lot of my "learning" time is taken up by having to research and discount, for myself, a particular type of comment on the course written by someone with obvious knowledge of the standard sceptical arguments and resources.  Of course referencing sceptical/alternative scientific research is of immense value and helps us to firm up our own understanding, but I do think it might be helpful for certain key points to be emphasised to the learners. A particularly important one being to make sure that we evaluate those resources before wasting any time reading or relying on their findings, or linking to them for other learners. Key to evaluating a resource is looking at the authority of the author, their area of expertise and their body of peer reviewed work. http://guides.lib.berkeley.edu/evaluating-resources

Although the Internet is a major and important source of information for those of us who are interested in science, I do have some unease about how easy it is to cherry pick and pull together our own conclusions, especially in a rather contentious subject like climate change. After all, being able to do an Internet search bears no comparison to spending years doing scientific research and study. If you had a serious medical condition would you rely on your own reading of the internet to come up with the best method of treatment, or would you rely on your medical specialist? You might back up the advice you were given with your own research, and maybe get a second or even third opinion, but it's unlikely you'd need 97 of them :-)).

http://snri.ucmerced.edu/news/climate-scientists-launch-brainy-attack-inaccurate-news
http://climatefeedback.org/about/

Lastly, this week I found a link to the TV series "Tipping Points" which was based on Professor Lenton's work. I have started watching, with amazement. The dedication of the scientists involved is incredible, with much of the filming done on site, in Greenland, the Artic and so on, as they go about their work. I don't know why the series wasn't shown on UK TV, but it should have been. The videos seem to have been uploaded to YouTube by a Danish educational video supplier (self-described) so I presume the licensing is OK (but please let me know if you think otherwise) They are available here:

1. Permafrost of the High Artic
2. Icesheets of Greenland
3. Forests of the Amazon
4. Floods and Droughts of Africa
5. Dangerous Rise of Oceans
6. Water Crisis India

Week 3 - Reflections


Extreme Weather, Chaos and Tipping Points


The student poll currently shows that 28% of us believe that extreme weather events are the biggest threat we face as a result of global warming.

We have seen two examples this week:- Australia has suffered record high temperatures, and over 180,000 people in California had to be evacuated due to fears that the Oroville Dam would suffer structural damage in heavy rains following a long period of drought - a very worrying example of how the infrastructure in the developed world is likely to be challenged in the future:

“"With climate change, with more extreme events — drier drys and wetter wets — more big storms, it becomes more difficult to operate a system that was built for a climate we no longer have."
Pacific Standard - Feb 16th

But the course is also showing us that the weather patterns that will be produced as a result of climate change cannot be easily predicted. The only measurements we can reliably track are the gradual changes in temperature, sea-levels and ice melt. Maybe this is one of the reasons that there is a disconnect between what the scientists are telling us, and public perception of the need for urgent political action - if science can only say that the UK (for example) will be somewhere between 1.5
and 2.5 degrees warmer by around 2060 and it cannot predict that the houses along the river Ouse will be flooded in 2018 and again in 2022 perhaps the situation does not seem so bad after all? This is a major challenge for communicating climate science.

I am very interested to explore why it is so difficult to predict what the weather will do as the climate changes, and so I am looking forward to learning more about models and predictions in next week's module.

In the meantime I found an interesting description of an example (the Great Storm of 1987 ). It is covered in the first few minutes of this lecture - although the whole of the video is worth the effort if you have the time.



The theme of "choas" and how it relates to climate change was also brought to my attention when, during the feedback video, Professor Lenton said that he regarded "the risk of major tipping points" as the greatest danger associated with climate change.

"A climate tipping point is a somewhat ill-defined concept of a point when global climate changes from one stable state to another stable state, in a similar manner to a wine glass tipping over. After the tipping point has been passed, a transition to a new state occurs. The tipping event may be irreversible, comparable to wine spilling from the glass: standing up the glass will not put the wine back.

The IPCC AR5 report stated with medium confidence that precise levels of climate change sufficient to trigger a tipping point, defined as a threshold for abrupt and irreversible change, remain uncertain, and that the risk associated with crossing multiple tipping points increases with rising temperature." Wikipedia

I will be doing some more research on tipping points this weekend and will post up any useful links I find.

Tim's work on tipping points - thanks to Liam for providing them:

http://www.thetippingpoints.com 
https://yosemite.epa.gov/ee/epa/eerm.nsf/vwAN/EE-0564-112.pdf/$file/EE-0564-112.pdf - great figure on the first page 
http://geography.exeter.ac.uk/staff/index.php?web_id=Timothy_Lenton&tab=research - tim's webpage, it's got a load of links to his papers and tipping points work :)

https://www.youtube.com/watch?v=QwuCywghriU  - Talk from 2016 - Early warning of climate tipping points.


Week 2 - Reflection
Data, Obfustication and Reputation
We have been looking at data this week, recent data taken from actual measurements and data "constructed" using proxies to tell us about the past (e.g. tree rings, ice cores and fossil pollen).

I found all this very interesting and it also got me thinking about the importance of the perceived integrity of the data that climate scientists publish. After all, we have to be able to trust the data, because it is used by governments to formulate policy (in theory anyway, in actuality they seem to be doing a pretty good job of ignoring it).  But we also have to acknowledge that climate science is moving forward all the time, discovering newer and better ways to evaluate evidence. In addition more powerful computing means data can be modelled far more accurately. This is bound to result in some previous models being superseded and data being occasionally “overtaken” by more recent results.

Last Sunday there was a so-called “expose” in the Sunday Mail by the journalist David Rose which claimed to show that scientists had manipulated a newer set of data on global temperatures in order to show higher levels of warming and thereby influence the outcome of the 2015 climate summit. As it turned out the graphs Mr Rose published in order to demonstrate his point were wrong (they used an incorrect baseline when comparing the data to previous date.) The corrected graph is shown below.

http://www.realclimate.org/index.php/archives/2015/06/debate-in-the-noise/


In addition, John Bates who he names as his “whistleblower” does not actually dispute the data in question, just the protocol surrounding its release. The motivation behind Mr Rose’s work seems to be an ongoing attempt to discredit the recent data being published by climate scientists that disproves the existence of the so-called “pause” in global warming. (See my previous blog post for another recent example of Rose’s “work” in this area). The pause is very important for climate sceptics because they want to believe, or persuade others to believe, that, if it exists (it doesn’t btw), then the climate is not so sensitive to carbon emissions after all.


So was the whole data scandal from last week a storm in a teacup? To anyone who did their research - yes. But very few of us do drill down very far into these things, so some damage to the public view of climate science will have been done, and then there is the amount of time that scientists have wasted discussing and debating the whole thing. In addition there was a lot of attention given to the matter in the USA where the politics of climate change are currently a very key issue. Journalists who cynically damage the reputation of climate scientists, and the veracity of the data they publish, must sleep at night, but sometimes I wonder how.


In conclusion I would like to quote in full a letter from the comment section of Judith Curry’s blog where there was extensive and in depth discussion of this story. (Judith Curry is a somewhat controversial figure in climate science so I suggest you do your own research before reading the rest of her blog).


  • Rt. Rear Admiral David Titley, former NOAA chief operating officer:
    In summary, the Mail on Sunday has found a disgruntled ex-NOAA employee and is using him to construct alternative facts about the climate. Unfortunately for all of us, the air will keep warming, the seas will keep rising, and the ice will keep melting, regardless of the Daily Mail’s fanciful claims and accusations. The real atmosphere is impervious to alternative facts.

    There is both a NOAA internal process on scientific integrity (my office ran it when I was at NOAA) and the opportunity to submit allegations of wrongdoing to the Department of Commerce Inspector General who, if there is reasonable evidence to substantiate the allegation, would undertake an independent investigation.

    Is the science bad? No. Karl et. al. was published in a high-prestige, peer-reviewed journal, where the reviewers were almost certainly eminent scientists external to NCEI and NOAA. More importantly, the Berkley group (originally founded to disprove the NOAA and NASA temperature recorded but ended up confirming their validity) as well as other external organizations, such as the UK Met Office, have all subsequently INDEPENDENTLY replicated the Karl et. al. results. That’s the gold standard of science, not some NOAA internal bureaucratic procedure that may or may not have been followed.

    Is the earth continuing to warm? Yes

    While the arguments about ARGO floats vs. WWII shipping sea water injection temperatures vs. Satellite SST’s are fascinating to the dozens of scientists who care about such things, our knowledge of global warming and climate change is built on overwhelming, independent lines of observational evident, understanding of the basic physics that goes back to the mid 19th century, and our ability to accurately project the overall global warming in computer models for over 40 years. Nothing in the Daily Mail article refutes any of this evidence.
Further Reading:
https://www.carbonbrief.org/factcheck-mail-sundays-astonishing-evidence-global-temperature-rise
https://arstechnica.com/science/2017/02/article-names-whistleblower-who-told-congress-that-noaa-manipulated-data/
https://andthentheresphysics.wordpress.com/2017/02/05/expose-david-rose-does-not-understand-baselines/
https://pressingwax.wordpress.com/2017/02/13/breakdown-of-an-anti-science-hit-piece-in-national-review/


Week 2 - Explaining Snowball Earth - Feedback Diagrams (07/02/2017)


In earth's past there have been periods when there has been a greater concentration of “greenhouse”  gases in the atmosphere. The warming this caused was gradually over time counteracted by the negative feedback of  “chemical weathering” - carbon dioxide and rain water combining to form carbonic acid and dissolving silicate rocks. The carbon in the form of sodium bicarbonate ions then washed into the oceans where it returned to the ocean floor in the form of carbonate rocks formed from the shells of sea creatures. In this way the “warming” carbon dioxide from the atmosphere was therefore transferred to the lithosphere via the hydrospere.


This caused global temperatures to drop due to removal of carbon from atmosphere and therefore ice coverage grew, resulting in the positive feedback of more heat reflected away from surface (increasing albedo), further increasing the positive feedback of more ice and so on. "Snowball Earth" was a result of a certain tipping point being reached when the ice eventually covered the whole of the globe. However, volcanic activity and the fact that the increase in ice then caused a decrease in chemical weathering meant that the carbon in the atmosphere increased again and so the process by which “snowball earth” was caused went into reverse.


Diagrams


I did make an attempt to put this all into diagram format myself using the GoogleDraw tool but wasn’t at all happy with the results. So instead I’m including one I found on the Pennsylvannian State University site - credited to David Bice.







Week 1 - Discussion point - Communicating Science

Liam's blog post.
An article from a recent post on andthentheresphysics

I'm still thinking about this question and hope to write more soon. It is a tricky one because there's a big part of me believes that the scientists have been shouting loud and hard for some time. The problem is that they've been getting drowned out by "noise" from interested, influential and resourceful (i.e rich) parties and we've just not been listening hard enough. 

Week 1 Reflection Questions (1/02/2017)


1. What the key scientific principles that explain climate change including the greenhouse (blanket) effect?
Radiation from the Sun passes through the atmosphere, some of it is reflected back from the surface and objects on the surface. The proportion that is reflected back depends on the nature of the surface of the earth (its albedo) - ice and snow have a high albedo causing a high amount to be reflected, the open ocean a low one. In addition a proportion of the heat radiation is absorbed by "greenhouse gases" in the atmosphere and then radiated back to the earth's surface causing warming. The climate changes as the nature of the surface (i.e. the albedo) changes and as the greenhouse gases increase.

2. What are the key feedback mechanisms that help to explain why our climate is able to “self-regulate”?

Water evaporation, albedo, radiation

3. How can our climate be conceptualised as a system containing a series of components that interact with one another?

"It is a system that encompasses five key components, the atmosphere, the hydrosphere-- this is dominated by the oceans but also includes fresh water, rivers, lakes, and groundwater-- the biosphere-- all the living things and soils-- the cryosphere-- ice sheets, sea ice, and mountain glaciers-- and finally the lithosphere-- the surface of the Earth's crust." - Course video. "The climate system, feedbacks, cycles and self-regulation". The system incorporates interactions between the different components which are called cycles (for example the water cycle - radiation heat causes evaporation, cooling then causes condensation (clouds) which then cause(?) precipitation back to the surface.

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