Wednesday, January 11, 2017

BlueSkiesResearch.org.uk: The AGU review 2016

We’d rather enjoyed our last trip to the AGU and had always hoped to go back some time but it’s a long and expensive trip from the UK especially without having access to JAMSTEC’s generous travel budget. Back in February, PEN had decided to propose a session at the AGU this year, and there was at least a strong hint that some financial support might be available to presenters. So we were mulling over the possibility of going back, when a few months later, both jules and I received separate invitations to present our work there in unrelated sessions. We’ve never both been invited to speak there in the same year, so this all seemed too good an opportunity to miss. We cleared our schedules (ha!) and arranged the trip, starting with a couple of months at NCAR.

My invitation was to a new session which covered betting, financial markets and insurance as it relates to climate change. At least, it was new to me, possibly something similar has been tried in the last few years. It didn’t attract enough abstracts for a full session on its own, so was amalgamated with a long-standing session on climate model evaluation and interpretation. Jules was invited to a session on (paleo)-climate sensitivity, which also got folded into a larger session on cloud feedbacks.

We also submitted a poster to the PEN session on combining paleoclimate modelling and data, which focussed on our new attempt at reconstructing the last deglaciation. Interestingly, I found a presentation I gave back in 2009 at a different meeting proposing this idea (and an acronym – 21kaRP), but we had too many other things on our plates at that time and didn’t pursue it further. It is much more timely now that PMIP is pursuing a coordinated experiment aimed at simulating this interval with state of the art GCMs.


from window of Westin

As well as booking our favourite hotel (surprisingly good value through the AGU site, especially with two people to share the room costs) we spent a bit of time surfing tripadvisor for the best places to eat, which threw up a number of old favourites and a handful of new places to try. As a result of our research we didn’t bother with lunch on the flight but instead headed straight to House of Nanking for sesame chicken after landing on Sunday afternoon, before heading off to registration to avoid the Monday morning queues.

We didn’t find the schedule to be completely packed with must-see stuff, but there was enough to keep us interested most of the time. It’s not really sustainable attending lectures non-stop from 8am to 6pm anyway, though the remnants of a bad cold meant we didn’t have much energy for enjoying SF’s sights and shops. We had a few meetings arranged to do outside of the AGU conference itself, which kept us busy in some of the quiet times and made the whole week that much more worthwhile.

Monday was a particularly thin day, so instead of attending lectures we focussed our attention on discussing some joint work with others for most of the afternoon and on to dinner. Tuesday was mostly data assimilation. I find it interesting to see people still pushing the boundaries of what is possible with ensembles and particle methods. One interesting question is how and why the particle filter and even ensemble Kalman filter can work so well, when they should both basically fail for the modest ensemble sizes which are practically achievable. There seems to be some debate as to how these results are best interpreted…

Wednesday was a busy day for me, with a poster first thing and then a talk later. Our poster on the deglaciation is here or perhaps here if the AGU site changes
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Unusually, the poster session was particularly well-attended and useful. I think this was a fluke of scheduling, as there wasn’t much of a clash with anything except with Bette’s Emiliani Lecture at 11:20am. So basically everyone who was interested in paleoclimate went to the posters around coffee time and stayed for an hour or so, before heading off to the lecture which was great.

It’s available though the AGU on demand streaming service, which doesn’t seem to have as much as in previous years, or perhaps I’m misremembering that. Anyway, several of the major lectures are available (the Schneider lecture by Battisti was another one that we attended), though not many of the normal short-talk sessions.

My talk (here as pdf) was late in the afternoon. Being shoehorned into someone else’s session gave me some justification, I thought, in going beyond the narrow remit of my submitted abstract to talk a bit more generally about betting and betting markets. So I enjoyed a brief meander through a subset of the betting stories that have popped up in recent years. The AGU has gone widescreen (maybe years ago, but this is the first time we’ve bothered formatting for it) which is all very well but there was at least one room where a bit more attention could have been paid to ensuring that the image didn’t extend beyond the white screen, clipping off figure captions and titles. We made sure our text wasn’t too close to the edges and it wasn’t a problem for us.

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A celebratory beer

On Thursday, jules (to whom I had, just in time, successfully passed my cold) gave her talk, which had also been agglomerated into a larger session. This was a repeat of the Pliomip sensitivity paper, nothing that exciting to those of us who knew about this work though a good chance to talk about it with a new audience who mostly knew about cloud feedbacks and modern data and had relatively little exposure to paleoclimate. It actually clashed with a rather similar talk in a different session which I went to instead, so I can’t tell you how great it was🙂 For lunch we penetrated the AGU editors’ lounge which serves much larger lunches than the EGU equivalent. The pretext for this free lunch was to discuss using paleoclimate to estimate climate sensitivity with some colleagues at least one of whom is, we hope, an AGU editor of some sort. We finished off the day with a dinner at Scala’s anyway, where I had a very good ribeye steak.

By Friday we were a bit tired, and there was nothing that great on. We went to learn a bit about renewable energy which was quite fun, but it petered out towards the end. Didn’t have energy to go out for dinner so Pearl’s deluxe burgers had the honour of a second visit in the week. We also had plans for Saturday morning so weren’t really on for a late night.

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A few years ago we entered the AGU fun run and were caught in a downpour, which wasn’t actually all that much fun. Plus, the 7am Wednesday start time made it impossible to get back in time for the early session and we were particularly busy on Wednesday this year including the poster presentation first thing. Therefore we decided not to do it this time. I had however spotted that there was now a parkrun on Saturday mornings at Crissy Field (one of only a handful in the USA). So we booked an afternoon flight back to Denver, and planned to take part in this, at least provisionally depending on the weather and how we felt after a week of AGUing. As it turned out, after a fairly wet and drab week for the conference, Saturday morning dawned sunny and perfect, so we greatly enjoyed a quick trot up and down the shore with great views of the Golden Gate Bridge and all the rest of it.

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By chance it was the 100th running of the event, so there was perhaps a larger than average turnout and even cake at the finish. So that was quite a treat to end the trip with. The return flight was then heavily delayed due to another snow storm in Denver, and when we finally got to Boulder we had to trudge back home from the bus stop late at night through several inches of snow with temperatures of -20C which was a bit of a shock to the system. I don’t think I would much like to live in Boulder long-term, it’s a struggle to go outside in those conditions though I suppose some must enjoy the skiing.

Next year the AGU will be in New Orleans, then Washington DC the year after, while the Moscone Centre is being renovated in some way. Doubt we’ll be at either of them, but you never know.

Saturday, December 31, 2016

BlueSkiesResearch.org.uk: Blueskies tour of the USA


The possibility of visiting NCAR has been at the back of our minds for some time, so when the rare honour of invitations to speak at the AGU Fall Meeting in San Francisco plopped into both of our inboxes around June, we swung into action. A couple of months at NCAR rounded off with an easy hop to SF seemed too good an opportunity to miss, so jules sent an email to Bette who leads the paleo group at NCAR to ask if she could host us. There was a bona-fide research reason for the visit, in that we are hoping to extend/supersede this work (and simultaneously improve on this reconstruction!) by blending together model simulations with proxy data records to create a complete reanalysis of the last deglaciation, 21ka to the present. There’s a forthcoming PMIP-supported plan for GCMs to simulate this entire period (the main instigators being next door in Leeds is a happy coincidence), but this may take a couple of years to actually happen, as 21 thousand years of simulation is a huge task for complex models. However, Bette is ahead of the pack having done this a few years ago with a slightly lower resolution model, so our plan was to use her model output (among other things) to work out how to do it in the meantime.
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The view from (near) NCAR

Having started to arrange the visit, we then started fishing around for support and found out that NCAR (subsistence) and PEN (travel including AGU costs) were prepared to help us pay for the trip, for which we were and are very grateful. Then to top it off, another invitation arrived, for a workshop on "model dependence and sampling strategies in climate model ensemble prediction"…to be held at NCAR in early December, immediately prior to the AGU! I expect that the organiser Gab Abramowitz was really only inviting me out of politeness with no expectation that I’d fly there for a two day meeting at my own expense (they had no money for this) but of course we were now planning to be there so I was delighted to be able to accept. It then turned out that Reto Knutti was already at NCAR on a year’s sabbatical, and a couple of his ex/current students who were working in this area and are now also supervised by Gab visited briefly en route to the AGU along with Gab.

We arrived in mid-October, though our luggage did not. Our departure from Leeds had been a bit disorganised, as the computer system there was down and all check-in/luggage drop had to be by done by hand. The resulting delay gave us a tighter than planned connection at Heathrow (including a terminal change) and therefore it wasn’t a great surprise that our checked baggage with hand-written tags didn’t turn up in Denver. So our first couple of days in Boulder were filled with emergency shopping (along with scrounging some free googlewear off our friend Rob who works there).

Fortunately all our stuff turned up over the following week, albeit in 3 separate deliveries all in the middle of the night which did nothing for the jet lag. Most of the luggage consisted of two travelling bicycles (S&S couplers) which we had used some 19 years previously on my first visit to Boulder. That didn’t end so well – for us or the bikes (evidence) – when we met a Harley-Davidson on the wrong side of one of the twisty canyon roads, but fortunately there were no similar incidents this time around. Boulder is great for cycling around, being pretty much flat with a sunny dry climate and a wonderful network of bike/pedestrian paths many of which follow various creeks though and across town.
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Boulder creek and its path

Our apartment was an easy distance for cycling (and sometimes running) to work, 6km direct (though with a 250m climb) with a range of longer options for more energetic days. NCAR also runs their own regular shuttle up to the lab and there’s good public transport in Boulder, so we didn’t plan to hire a car for our stay though thought we might do so for one or two weekend trips to the surrounding countryside and national parks. In fact in the end we forgot to pack our driving licenses so couldn’t do this, which didn’t turn out to be much of a hardship as there was enough to keep us busy in the vicinity of the town. Just outside the town, there are some huge hills to climb and some decent mountain biking.
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The indirect way to work…
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…and the really long way home!

NCAR is really well set up for visiting, there were several offices set aside for the use of visitors and we were up and running with ID cards and computers and internet access etc in a couple of hours on our first day, which would not likely have happened at JAMSTEC, or anywhere else we’ve been before. There’s also a very good canteen which we made the most of, even including some breakfasts. NCAR seems to be on everyone’s itinerary – there were many seminars from short-term visitors, and it was quite a surprise to bump into someone we knew from Bristol who was also passing through. So just being there was a good opportunity to meet with a range of people, though in fact our main work on the deglaciation turned out to be largely self-contained.

Snow usually appears around the middle of October in Boulder, but we were lucky to arrive during a particularly dry autumn and had a full month of warm sunny weather during which we made full use of Boulder’s various leisure opportunities. We quickly bought some cheap old MTB tyres from Community Cycles and enjoyed visits to Dowdy Draw, the West Magnolia Drive trail area, and Marshall Mesa.
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Somewhere on the trails

We also climbed up most of the mountain roads – Magnolia Drive to Nederland, Flagstaff, through Jamestown to Rob’s place and finally up and down Lee Hill Drive.
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West Magnolia trails

I also found a few of the local running groups and went out for a couple of rather gentle Sunday morning runs with the Boulder Roadrunners and more challenging runs with the Boulder Track Club who seemed to consist of quick to super-fast runners. Luckily the runs were basically out and back routes so I could watch them all zoom off into the distance and after turning round a bit early they would all zoom past me on the way back too. jules and I together joined the Trailrunners for the first hour of one of their monster mountain marathon days. We just went up Flagstaff but most of the rest went all the way to Bear Peak and back, about 24 miles with a lot of climbing.

The work went well, though it’s far from finished and so we don’t have a lot to report yet. We  presented this poster at the AGU which summarised our research so far:

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In short, it looks like at a minimum the basic idea should succeed fine but it’s a bit early to say anything about what the overall result will look like, and there are plenty of opportunities for improving on the very simple method we used. It will also be very helpful to get some more PMIP simulations but we may have to wait some time for these, so there’s no great rush for the methodology but we will keep working on it as time allows.

Towards the end of our visit, just about when we were starting to get a bit bored with sitting in an office and working on the deglaciation, we had to shift gears to prepare not only for the AGU meeting but also for the workshop on climate model ensembles. In all we had 4 presentations to give on entirely unrelated topics in a bare week (me talking twice, jules once, and a joint poster).

I don’t think anything from the workshop is available on the web (it was a rather small and informal affair) but there are plans to write some sort of review paper. There was no real breakthrough but there was hopefully some shared understanding of the different ideas that people have come up with. I’ve also got a month to revise this manuscript, and now have a significant improvement to put in to it. Although the new idea didn’t arise directly at the meeting, having to give a presentation about it and field questions afterwards did provoke the inspiration.

By this time the snow had arrived, giving a very different feel to the daily commute. We didn’t really have enough winter clothing and temperatures down to -20C (with a daily max of -10C) were a bit of a struggle, though it looked pretty when not actually snowing:
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A snowy ride
from window of Westin

Straight after the workshop we flew over to San Francisco for the AGU meeting, about which I’ll write separately. For now you can make do with the view from our hotel window (on the one sunny morning we had).

We came back and had a couple of days in Boulder, just enough to empty our office and tidy up the apartment and pack all our stuff for the long haul back to the UK. No drama on that trip, and a bizarre lack of jet lag following our return, perhaps because it’s so peaceful and dark at night here in Settle that there’s really no excuse to stay awake.

While we were in the USA, it seemed like there was some sort of election going on. The result didn’t go down well with most (perhaps all!) of the staff at NCAR. I hope the institute survives for other people to have as enjoyable and useful visits as we did!

Wednesday, December 07, 2016

It's colder in Boulder

Presently hunkered down at home awaiting the forthcoming -17C minimum temperature overnight, which is something I don't think I have experienced before. Possibly came close to it up a Japanese mountain once or twice. We've been very lucky with the weather for most of our trip, but it's certainly winter now!

At the start of December there is the annual “Colder Boulder” race, a counterpart to the “Bolder Boulder” in May that we've run a couple of times before. The December one is only 5k and has many fewer participants, allowing the event centre and finishing area to fit into an indoor arena which is probably a good idea given the season. In the event it was pretty comfortable, a bit chilly but bright and still. Biggest problem was the altitude, but the modest hills and numerous corners on the course also contributed to a slow run. Oh, and it was a good 100m too long too. 


Taking account of these factors, I was reasonably satisfied to duck under 20 mins (by a whole second) and jules was also relatively fast at 26:05. In fact we were both the fastest in our respective age categories, thanks mainly to the organisers' decision to classify by year rather than the more usual decade (meaning there were only about 10 runners in each category). We are hoping to reap the benefits of the altitude training when we return to sea level shortly!

Sunday, November 27, 2016

“stop this ridiculous Brexit nonsense ever from happening”

How times have changed. It's hard to imagine anyone saying this on Any Questions 5 months ago and being met with strong applause. Is there finally some light at the end of the tunnel?

Friday, November 18, 2016

[jules' pics] Winter Wonderland

Yesterday it was cold, grey and snowing so we stayed at home a fought bitterly about climate sensitivity all day and then enjoyed the cultural experience of attending our Condominium Management Meeting. That was fun. Today it's back to business as usual, only the landscape has changed colour, and it is freezing cold outside instead of boiling hot.


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Posted By Blogger to jules' pics at 11/18/2016 06:08:00 PM

Wednesday, November 16, 2016

[jules' pics] The probably actually last day of summer

If the forecasts are correct then summer ends today. So, we took the morning off and did an MTB trail near Boulder, called Dirty Bismark.  

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It was a lovely ride and we finished it off by riding to the nearest pretentious cafe to NCAR where we enjoyed coffee and pastries. The only problem was that then we had to ride up the hill to NCAR, in the hot sun after already having done 2:30h of bone shaking cycling. 

 Strava trace here.


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Posted By Blogger to jules' pics at 11/16/2016 10:08:00 PM

[jules' pics] Last days of summer

Summer isn't supposed to last this long in Boulder. Snow usually falls in October, but the first snow is expected tomorrow. Am very excited, as the temperature is max 26C today and expected to reach only 6C tomorrow. Anyway, forecasts seem to be easier in this part of the world, with tomorrow's precipitation already being predicted this time last week! So, to make the most of the dry weather, last Friday we cycled via Magnolia Drive to Nederland, stayed overnight in a luxury hotel, did a bit of mountain biking and then freewheeled down the hill home.

Naturally the adventure started at a pretentious Boulder cafe.
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Packed lunch stop was near the top of the road section of Magnolia Drive
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After which the views opened out
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And the sky was very blue
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Luxury hotel was the Boulder Creek Lodge, 1st of 1 hotel in Nederland!
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Ate own weight in pizza
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Mountain biking the next morning was tough on our rigid all-rounder bikes, while carrying overnight gear at even higher altitude than Boulder (2600m). But we made it round the West Magnolia loop and then had brunch at the conveniently located Sundance Cafe.
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And then it was back down Magnolia Road (including just a couple of easy MTB trails).
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The reason I am looking so happy in this pic is that the Magnolia Drive ride has been a long time coming. Nineteen years ago we came to Boulder for a couple of weeks on the way back from a conference in San Francisco with the idea of doing some cycling. One ride that James had planned was the Magnolia Drive dirt road. But, unfortunately, we got knocked off our bicycles by a motorbike on one of our first rides, on our way back from Ward, and that was the end of the cycling for that trip, although we got to experience lots of other interesting Boulder things, like ambulances, dentists, surgeons, hospitals, state troopers and lawyers.

No problems with traffic on this ride...
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Strava traces here and here.

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Posted By Blogger to jules' pics at 11/16/2016 09:39:00 PM

Tuesday, November 15, 2016

SuperMoon

For all the reader of this blog who was in cloud when the supermoon appeared.

It was super. Could see all the men, women and bunnies!

Friday, November 11, 2016

Apocalypse now?

Lots of people have asked about this paper (which I think is open access).

To cut a long story short, it's not silly - the authors are entirely respectable and the work is interesting - but I don't think it is really that credible in terms of overturning established consensus. In fact it looks to me like they've gone astray in a few ways which add up to provide plenty of reasons for doubting the result.

The underlying idea is interesting enough and I have no problem with it in principle. They looked at climate change over multiple glacial cycles, to estimate not only the climate sensitivity, but also tease out how much this varies with temperature. Their observed temperature record comes from a handful of long-term proxy records of sea surface temperature, just 14 in total, which do not give very good global coverage. So they start by calibrating these records to a global mean temperature by comparing the local (proxy location) to global temperature at the last glacial maximum as simulated by models. The LGM temperature change arising from their 14 proxy records scaled to global temperature is about 5C colder than pre-industrial. This is a fair bit colder than the 4C we got with 400 data points over both ocean and land. But not content with this, they then average it with the mean of the PMIP model simulations, which is 6.5C colder than PI, thus getting a cooling of almost 6C.

Edit: Thanks to an email from Axel, I've had a more careful read and the above is wrong. One estimate is the PMIP models scaled to match data ("proxy-based"), another is their LOVECLIM simulation scaled to match a different data set ("model-based").
 
It is probably defensible to use the PMIP models in this way as some sort of independent estimate of the LGM state, but surely it is inconsistent to not then also use the PMIP models to estimate the cimate sensitivity and/or its nonlinearity. Anyway, this cold LGM state feeds through into a high sensitivity. An important additional factor here is the nonlinearity which they diagnose by comparing temperature to net forcing throughout the time series. I think a fair bit of this nonlinearity relates to the very high interglacials which are at best poorly calibrated since they only calibrated the proxy records to a fully glacial state. Interglacials have much smaller global temperature signal compared to the present, with the regional differences being much more important, and it seems doubtful whether a single scaling applied to these 14 proxy records could represent the true relationship with adequate precision for their purposes.  In support of this, the last interglacial appears to have extremely high warmth in their calibrated proxy record of some 3C above pre-industrial, which I don't think is widely accepted. On the other hand, some nonlinearity is probably quite plausible, so let's press on. Using the "warm" sensitivity of 4.9C/doubling, they then generate a transient prediction, using a simple energy balance with the ocean heat uptake factor again taken directly from the CMIP models.

Disappointingly, their plot of the transient warming from 1880-2100 doesn't show the actual observations up to the present. It is hard to be precise from eyeballing a computer screen, but it looks to me that their new improved prediction is already way ahead of observations. It suggests a warming that first reaches 1C (relative to 1880) back in the early 1990s before Pinatubo, rebounding from that brief dip to reach about 1.5C by the present. HadCRUT4 shows rather less warming that this, with even the current extraordinary hot year (boosted by a strong El Nino) not reaching 1.2C on that anomaly scale. In my view failing to show, or discuss, this discrepancy is a major failing of the paper. If they think it can be explained by internal variability then they should have presented that discussion and I'm surprised the reviewers let them get away without it.

Edit: ok, here is a very quick and dirty attempt to show what their pic would have looked like with real temperatures on it:


Not a great graphic, I just scaled the hadcrut pic off here and tried to line it up with the authors' own axes, matching the baseline temps around the end of the 19th century.  As anticipated, recent years are well below their prediction, with 2016 just about reaching the CMIP mean.

Edit: Axel claims that internal variability can explain this discrepancy, but I don't believe it. The magnitude of decadal-scale internal variability is about 0.1C (Watanabe et al 2014 and Dai et al 2015) and this new forecast would be even hotter if it wasn't also hugely overestimating the response to volcanoes.

So, in summary, nice try, but I don't believe it, and I don't really think the authors do either.

[Blog post title inspired by the Mark Lynas quote which is not the authors' fault. Incidentally, it is disappointing to see journalists falling for the parasitic publishing scam in which "one of the most respected academic journals" cashes in on its name by setting up numerous sister journals which share some elements of the name but neither the editorial policy nor barriers to entry. "Science advances" is not Science and it's only been around for a year or so, nowhere near long enough to have any sort of reputation. But if journalists don't know the difference, scientists will happily pay the steep publication charge and reap the publicity benefits. Nature have been doing this for a few years now (eg Nature Communications) so it's hardly surprising Science have followed suit.]

Wednesday, November 09, 2016

Bigly and Brexit

I am Jack's complete lack of surprise, but at least we're trying to hit bottom. Late August 2015 I remarked to an American friend that if the US could elect Reagan in the 1980s then Trump could be elected in the 2010s. Unfortunately he laughed. But really it only hit home yesterday afternoon when I wrote to my Dad, "Let's hope that this time the Americans are less stupid than the British." I felt a deep sinking feeling that, for sure, Trump was going to win. Why? The Americans' one remaining small act of deference to the British, is to act just that little bit more stupid.

I wrote to someone a little while ago that if Brexit is the Apocalypse then Trump will be Armageddon. But I'm not so sure about that now. I'm hoping that this is the Dead Cat Bounce of the angry white man and that when such evil is exposed to the light of truth it will wither and die. Of course it is up to us to do the exposing to make sure that happens.

Some people are wittering about the death of democracy, but it is much worse than that - it is the death of reason (as in the Enlightenment) that actually matters. 

Very amused by Trump's speech in which he promised to follow Japan's lead and use concrete to solve all the problems. What you do is borrow and print a lot of money, and use it to buy concrete and employ companies controlled by the yakuza to build things that you do not need. The results are ugly and bad for the environment, but jolly good for employment. And the US has so much more space than Japan, it could keep this up for practically ever! The less amusing part was Trump's "reaching out" to everyone and promising to be nice to everyone who is nice to him. In my experience, people who claim to be "reaching out" will consider any form of constructive criticism as a direct attack. 

The internet suggests that pictures of cute cats are the answer, but I tried that for Brexit, and it didn't work. So, instead, here's some construction, which, curiously is occurring in extremely Democrat Boulder within currently Democrat Colorado... and of course it is happening for reasons of prosperity rather than politics. Not that this is necessarily the best thing either - I tend to think that if there is great growth somewhere, then somewhere else someone is being enslaved.

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And is Bigly also going to become an actual word now that Brexit has become one?