Bishop Hill The Krebs manoeuvre
Jul 12, 2013 Climate: WG3 Lord Krebs, the chairman of the adaptation committee of Lord Deben's Committee on Climate Change, has issued a report on how we are doing on preparing for the perils of climate change. The Independent has picked up on one of the themes of the report, noting breathlessly that British agriculture is in for a torrid time of it, with plants withering through lack of rain.
Within a decade, farmers could face a water shortfall of 115bn litres a year – almost half of the 240bn litres they currently use – with the south and east of the country, where most crops are grown, likely to be hit particularly hard. This could make it difficult – and more expensive – to grow water-intensive crops such as potatoes, carrots and fruit, the CCC warns.
Now future rainfall projections have been touched on from time to time at this blog, and once you get into the detail, it quickly becomes clear that nobody really has much of a clue whether it's going to get wetter or drier.
So how do we get to the Independent's predictions of apocalypse? If you go to the report itself you can indeed find the 115bn litre figure quoted. Here's the context:
There are larger uncertainties around future projections of rainfall in England than for temperature. Regional annual mean changes in rainfall could change by -10 to +10% by the 2020s (2010-2039), with changes in summer of between -30 to +20%, and changes in winter of between -10 to +30%. On balance, the evidence suggests that rainfall is more likely to increase in winter and decrease in summer, causing lower summer river flows.
This is about my understanding too. Overall, no change, summer could be lower or higher, perhaps on balance slightly lower.
However, when they develop their two scenarios for water supply, Lord K and his team come up with:
- a "less" water stress scenario with supply unchanged from today 120 Megalitres
- a "more" water stress scenario, with supply down to 100 Megalitres
It is the latter that produces a net deficit of 115bn litres once demand changes are taken into account.
This is rather odd: the range of summer rainfall changes coming out of the models is from a fall of 30% to a rise of 20%. Why do none of the scenarios consider such rises? But notice Lord K's use of what Mosher would call "high entropy language": not "high" and "low" water stress, but "less" and "more". See what I mean? Now read the small print:
- Scenario A (less water stressed) The supply scenario is based on the median of the wettest 1,000 sample runs from UKCP09 sampled data using the low emissions scenario (SRES B1)
- Scenario B (more water stressed) The supply scenario is based on the median of the driest 1,000 sample runs from UKCP09 sampled data using the high emissions scenario (SRES A1FI).
You will now see that the two water scenarios are based on different assumptions about greenhouse gas emissions. I think this means that the biggest increases in rainfall and the biggest decreases both take place for the high emissions scenarios - sometimes the model predicts a wetter future, sometimes a drier one. But by switching to the low-emissions scenario for the "less water stressed" scenario, Lord K and his team neatly avoid those horribly benign outcomes, leaving them free to base their advice on unremitting gloom and doom.
The predicted shortfalls in water are also dependent upon demand increasing. I don't propose to spend a lot of time on this side of the equation, but in essence it is predicted that the soil is going to be drier because of temperatures being higher.
There is high confidence that evapo-transpiration will increase rather than decrease because of the driving effect of higher temperatures. This is likely to lead to increased soil moisture deficits, particularly in the 2050s and beyond.
Which is odd, because just the other day, the former head of the Met Office, Lord Hunt, told us that lower summer temperatures were exactly what we should expect from global warming because it shifts the jet stream. Clearly Lord Krebs thinks that Lord Hunt is talking out of his hat.
In due course, the figures discussed above find their way to the Executive Summary (I assume the slight change in value is an error):
Our modelling suggests that, if current trends were allowed to continue, a gap could emerge between water supply and demand. In a dry year in the 2020s the gap could be nearly as large as total current agricultural abstraction of 120 billion litres per year.
Which I suppose is strictly true - their modelling does suggest that it could do this. But on the other hand, different figures are possible too - water supply is nearly as likely to increase and temperatures could even fall (if Lord Hunt is to be believed) in which case the situation would be completely different. But no matter, an argument has been put forward for a policy:
Reform of the abstraction regime must ensure that the price of water reflects its scarcity. This is required to incentivise improved irrigation efficiency and investment in on-farm storage, and contribute to ensuring sufficient water supplies in the future to meet growing agricultural demands.
It seems to me that rational policy development requires possible futures to be weighted according to their relative likelihoods. What the Committee on Climate Change have done is to ignore all benign outcomes and to base their advice only disaster scenarios. That is unacceptable and unforgiveable. Heads should roll.
Reader Comments (51)
Also about the report, https://twitter.com/richardabetts/status/354922246873161728
Outrageous you are not supposed to actually examine the content of these reports, think of the children; why won’t anyone think of the children?
/sarc off
Has Lord Krebs already forgotten what the last few summers were like or did he simply write that section of his report in the last two weeks when the weather was what nearly everybody would want in summer?
Our modelling suggests that, if current trends were allowed to continue…
The same old story of the alarmists and scammers: useless modelling and straight line trends.
And they can never imagine why they always get it wrong.
I agree, the Table does seem to be misleading. It is only one half of a 2 x 2 Table - the half possibly suggesting the worst outcome. And the Report certainly doesn't make it clear that this is presenting a worst-case scenario (albeit that might be a defensible thing to do). Unless I am misunderstanding it, I think the Table also over-simplifies the "demand" side in the same way. Many of the factors determing high demand have little to do with climate change (e.g. population growth). So "demand" is statistically confounded with "scenario". What was needed was a 2 x 2 x 2 Table - and some cells would then look a lot less scary.
To give the context of my tweet that Philip quotes, the conversation started when I said I disagreed with Damian Carrington when he wrote in his Guardian article that "most climate scientists are confident that summers in the medium term will become drier and hotter".
Carrington says that was what Lord Krebs told him (although TBH I'd be interested to see exactly what Krebs said to Carrington - recent experiences lead me to question whether the media really do represent what they've been told in an accurate way).
Climate scientists are well aware that projections of precipitation change are highly uncertain, so although there is a more of a suggestion of summer drying rather than wetting in the UKCP09 projections and IPCC AR4 projections, the uncertainties are huge and many of the models / projections also include wetting. So we are not particularly confident about it becoming drier (or indeed wetter).
However, this does not mean we are confident that there will be no change either. There could be large changes, in either direction. From a risk assessment perspective, it makes sense to think about the implications of decreased rainfall, and also the implications of increased rainfall.
The uncertainties in the precipitation projections are very clear in the CCC report (see the extract quoted in Bishop Hill's post above).
So what exactly are the projections for temperature in England?
The Hadley Centre Central England Temperature (HadCET) dataset shows that it is been decreasing rapidly since the turn of the century.
More nonsense from our dear Government, more numbers produced by use of fiddle factors.
I've no problems with the concept of more efficient irrigation & on-farm storage - more lakes & ponds.
How about spending the £36b+ that that unwanted trainset's going to cost, on pipelines to get water from the wet North, to the dryer South & East, if water is going to be such a problem?
This isn't the CCC, but in the end, it's all the same club. Found this from Rupert Darwall in the Spectator (via GWPF). Rather a good article, I think.
As Warren Buffett likes to say, forecasts tell you little about the future and a lot about the forecaster
http://www.spectator.co.uk/features/8959941/whats-wrong-with-the-met-office/
Don't blame the media (well .. a little bit, maybe); they don't have the expertise or the time to fisk the whole thing and anyway it's the scary bits that sell papers.
Richard Betts
and indeed they are but not in what Sir Humphrey called "the Janet and John bit" which you know and I know and Krebs knows and Deben knows is what the politicians read.What you say is correct but please don't add to the problem. You say
This report, like many, many others sent to government ministers, is dishonest — not because it is in any way inaccurate but because the conclusions and summary have been drawn in such a way as to mislead (deliberately, I am certain).
In 10 years time when we are up to our necks in water all summer, Krebs and Deben can point to their report and say, "well, we did make the uncertainties very clear", and the answer should be a quite blunt, "no, you didn't; you made damn sure the uncertainties were not clear!"
At the end of the day, Richard, its people like you that we need to stand up and be counted and tell those who write reports like this that they are not being strictly honest. We can all see how misleading this is and the potential needless expenditure and hardship that it could cause but we are not the ones that have the ear of government or MPs as posters on here have proved time and again.
Honest scientists prepared to provide government with all the facts and caveats in a form they can understand and act on are!
How about building some more reservoirs and incorporating hydro-electricity plant in them? Win-win.
Richard Betts - please, what do we know?
Richard Betts - "recent experiences lead me to question whether the media really do represent what they've been told in an accurate way)."
Welcome to the club at last Richard! I could (at the expense of wandering totally off topic) point to a major news story this morning where the truth is very much at the back of the pack. The 'media' is a very strange beast. People often express surprise that very little of the news they ingest is 'new'. There is a cycle of planning that is 3-4 days long, and what is covered and not covered has more to do with those pushing stories, or the journalists own agendas that it has to do with informing people. Once you realise this it's easier to spot it coming, and you can go hunting for facts rather than news.
I hope that realisation is not too disillusioning for you!
Richard,
Thanks for adding more info about that exchange I pointed to. The link I gave does in fact include the initial tweets you mentioned, but for some reason you need to scroll upwards to see the full set.
Jul 12, 2013 at 9:15 AM | Registered CommenterMike Jackson
This report, like many, many others sent to government ministers, is dishonest — not because it is in any way inaccurate but because the conclusions and summary have been drawn in such a way as to mislead (deliberately, I am certain).
Thr truthful, well-weighed answer that tells the blacker lie. (Rudyard Kipling)
Daily Mail Link.
As soon as they [MO] said that, I told a friend, "it's gonna be a scorcher - you'll see!"
So no knife blades springing from boots in the Krebs manoeuvre?
I saw John Krebs in the Covered Market, Oxford on Monday afternoon.
Thought he was buying a cauliflower for his supper.....but it seems he was really after a bit of seaweed to forecast the weather.....
Ahh, I see.
Rainfall may go up or down, but we'll assume it will go down and price water puniatively in accordance with our assumption so as to "manage demand" (while pretending the price hikes will significantly affect usage of what is a largely non-discretionary expenditure). Then we'll give the lucrative water contracts to our friends and family.
After all they have had so much sucsess (i.e. profit) using the same business model on other utilities - fuel, gas, electric - water is just the next utility on the list.
I'd be entirely unsurprised if the smart money wasn't already moving into bottled water supplies (STORW?), for despite this option being hugely expensive to the end-user, we can just tax regular supply to the point that bottled water appears economically competative by comparison.
Of course Co2 emissions would increase as a result of delivering water by truck rather than by the water mains, but if you thought any of this was about benefiting the environment then you are probably gullibe enough not to recognise this for what it is until your water bill doubles.
At which point the resultant public outcry will of course be met by government protestations (either from the red socialists or the blue socialists depending on whose churn it is) that, "the REAL problem is fat cat water board executives who have taken huge bonuses, while failing to maintain the system, leading to huge levels of wastage from leakage".
Whatever the party line, it certainly won't be the fault of the political parasites who were only trying to "save the planet" (nod, nod - wink, wink).
It will get wetter and it will get drier.
Climatologists refer to it as the Krebs cycle.
Build nukes with desalination plants in them. When the grid doesn't need the power, use it to desalinate by distillation, using water already pre-heated by the coolant system. The switching can be relatively instant and thus enable a greater proportion of hitherto slow-reacting nukes on the grid.
Most of all, plan to increase the water supply. There really need be no shortage of water nor a water plan based on austerity and unwarranted frugality.
I stopped believing anything Krebs said when, as chair of the Food Standards Agency, he stated that there was no good reason for buying organic food, forgetting that most purchasers bought it for what it didn't contain, rather than what it did.
I then heard him say that his favourite cheese was an unpasteurised variety that you could only buy in France, the health police having practically eliminated the technique here after the Lanark Blue incident.
Lord Krebs is clearly taking into account the melt water from Dr Viner's nonexistent snow.
It is not just rainfall.
1. Increased run-off from land into rivers reduces storage.
2. Rainfall in summer often evaporates.
3.Rainfall in winter recharges aquifers.
4. If rain in winter greater than ground percolation rate flooding and/or increased flow in rivers occurs. Therefore no recharge of aquifers.
5. Pre WW1 much of UK in winter was saturated , ditches were full, water meadow flooded( hence February Fill Dyke). Extensive drainage post WW1, including mole drains, excavators, large tractors, building in flood plains all reduced storage.
For the above reasons, changing the time of the year when it rains , run off , storage, intensity, duration of rain and not just annual amount will determine amount of water available.
It is not just rainfall.
1. Increased run-off from land into rivers reduces storage.
2. Rainfall in summer often evaporates.
3.Rainfall in winter recharges aquifers.
4. If rain in winter greater than ground percolation rate flooding and/or increased flow in rivers occurs. Therefore no recharge of aquifers.
5. Pre WW1 much of UK in winter was saturated , ditches were full, water meadow flooded( hence February Fill Dyke). Extensive drainage post WW1, including mole drains, excavators, large tractors, building in flood plains all reduced storage.
For the above reasons, changing the time of the year when it rains , run off , storage, intensity, duration of rain and not just annual amount will determine amount of water available.
This could make it difficult – and more expensive – to grow water-intensive crops such as potatoes, carrots and fruit, the CCC warns.but Britain is too wet?
Meanwhile parts of Northern Britain that are currently even wetter will be just right for the crops no longer suitable further south.
You really wonder at the level of intellect displayed. And this assuming the "worst case" -- which isn't actually that bad, comes to pass.
The Independent should be sold on the bottom shelf of every newsagent across the land, due to it having the editorial gravitas of a childrens comic. It is truly, desperately, dire.
Strange events can happen with water use and crop yields. The Murray Darling Basin is Australia's largest water system, serving 4 States with irrigation. We had a long drought a few years ago, when the flow in these rivers was close to cessation. Yet, here is part of a letter dated 8 Dec 2010, about 2 years after the drought. Note the lack of correspondence between yield and water use in earlier years.
http://www.geoffstuff.com/mdba.jpg
One has to dig into matters like this because the bland figures can hide significant changes.
Is decreased summer rainfall a coded reference to barbecue weather? While it goes without saying that this constitutes "extreme" weather in the UK, I do hope the membership of Lord Deben's committee is not infested with shills of the barbecue industry.
Then of course we get the wrong type of rain.
Senior officials making statements which conflict directly with the actual authoritative advice they've requested *and* been given >> in order to deflect criticism does not help any.
Especially when it's the public body charged with managing water eh?
Hi Athelstan
The Met Office did not predict a decade of wet summers. This was exactly the experience I referred to above, which makes me question the accuracy of media reporting.
The "10 years of soggy summers" seems to have come about because someone mentioned a piece of scientific research by Reading University investigating possible links between wet UK summers and sea temperatures in the North Atlantic, which suggested that the chances of wet summers may be higher in the next few years, but this still doesn't mean we won't get any average or dry summers - see here which says:
I was in the press conference where this was explained, and it was made very clear this was ongoing research and not a forecast. However, this still somehow ended up being presented as a prediction of "10 years of soggy summers".
not banned yet: We know that forecasting rainfall on timescales of seasons, years and decades is very challenging :-)
Whenever I have been present at an event subsequently reported by the press, I've found it hard to find any similarity between what I saw and heard and what was reported.
@Richard Betts
good to see you back with the BH faithful. Is it likely that the MO will spell out very clearly to policy makers that is is not possible to predict regional climate with any degree of accuracy over any meaningful time period?
We all know that the policy response would have to be one of adaptation but you would probably have to spell that out to the policy makers as well.
" Is it likely that the MO will spell out very clearly to policy makers that is is not possible to predict regional climate with any degree of accuracy over any meaningful time period? "
No, it is likely that they want a hundred million for a new computer. Will that be able to predict regional (or global, or local) climate for further ahead than doppler and satellites can see? No. Will they tell the government that? What do you think?
If all references to climate change were removed, and "soil organic matter" substituted for "carbon" - some of this report would almost make sense. The current agricultural model is showing its age and limitations and current husbandry needs change. Climate change is an irrelevance - farming has always been affected by inclement weather. Flooding is exacerbated by soil compaction caused by heavy machinery, and ill-advised drain- and track-cutting in peat uplands. Sort that and everybody will be a lot happier. Nothing can be done about subduction so CCC should just get over it. And disband.
What I think rhoda is that at some point the MO need to show a bit of honesty. I think we should all encourage Richard to persuade his colleagues that honesty is the better way.
Little by little.
A much more honest answer would have been to point out that a run of wet summers in Europe is not that unusual and that given that climate is a chaotic and largely unpredictable system it is virtually impossible to say whether the next few summers will be hotter, cooler, wetter, drier.
I know it's difficult especially since it means 'fessing up to something the Met Office should have 'fessed up to years ago, namely that you don't know anywhere near enough about climate and how it is likely to behave (as witness the detail in the very report we are discussing!) to make any sort of prediction about this summer or next summer or any summer in the next 50 years.
The message is stick to short/medium-term forecasting and leave the esoteric stuff to the ivory tower dwellers. It will work wonders for the Met Office's reputation, believe me.
My answer to this is always 'you are all going to die'.
To me it is a pack of stupid lies and I don't believe a single word of it. There is currently no way to predict the future state of the climate and perhaps there never will be. Computer divination is being taken for impending reality when it belongs in long term research.
Richard Betts - "We know that forecasting rainfall on timescales of seasons, years and decades is very challenging :-)"
More information content than a 137 page report....
:-)
Folks it is even worse than the brilliant posts of Mike Jackson have highlighted and as in so many areas of government policy, the words criminal ideological bias come to mind.
Some of you might have heard of Graphene; a new carbon derived substance that has remarkable properties. It was developed in the UK and won a Nobel Prize for the scientists involved. Graphene can be and has been produced in sheets with a thickness of a single atom. It is incredibly strong and people are still working out all of its potential uses however one extremely relevant use is already known; it can filter salt out of sea water! There is no need to build expensive desalination plants and indeed it probably makes reservoirs redundant. I am no scientist and so must be careful here but is it not the case that about 66% of the planet's surface is ocean?
The government should be aware of this because I have informed my MP Dan Byles (over a year ago) who is on the DECC committee.
"120 megalitres"???
If each UK person uses 150 litres/day (http://www.environment-agency.gov.uk/homeandleisure/beinggreen/117266.aspx) then x 365 days x 65 million people = 3.6 teralitres/year. Am I missing something?
"We know that forecasting rainfall on timescales of seasons, years and decades is very challenging"
Especially when it's in the future.. :-)
Dung,
Graphene is as over-hyped as all the "breakthroughs" in cancer treatment that you read about. As with so many things, the possibilities of the big picture are, well, large. But it's all those pesky fine details that cause the problems.
Budgie:
"120 megalitres...Am I missing something?"
Actually, the Bishop used the incorrect units -- rather than megaliters/year, it should be thousands of megalitres/year. Proper SI usage would be gigalitres (Gl), but for some reason the report uses "thousands of megalitres". Elsewhere, they use "billion litres".
As for the comparison, the the figures cited from the report refer only to agricultural demand, not household use (as your figures do).
Michael Hart
Everything is over hyped so what is new? Are you saying that my claim (their claim)? is untrue
Michael Hart
From Wikipedia:
And
from David L Chandler in "A New Approach to Water Desalination" MIT News.'Nature' reckons it's going to get hotter by 2018 - or maybe not... "What do we tell farmers?" asks one comment.
http://www.nature.com/news/climate-change-the-forecast-for-2018-is-cloudy-with-record-heat-1.13344?WT.ec_id=NATURE-20130711
Q:"What do we tell farmers?"
A:"We know that forecasting rainfall on timescales of seasons, years and decades is very challenging :-)"
Jul 12, 2013 at 2:05 PM | Richard Betts
Fewer press conferences = less misinformation passed on to the public.
I'm with rhoda and dung. It is the pinnacle of stupidity to worry about water shortages on a water planet, given the fact that the technology for desalinating water is well understood and getting more efficient as time goes by. We know how to produce almost unlimited amounts of energy that can be used to desalinate sea water. It is only liberal- and eco-obtuseness and obstructionism that prevents us from greening the planet to an extent that has probably never been seen in the past 4-1/2 billion years or so. Fresh-water supply shouldn't be a problem anywhere on the planet.