20 Things politicians should understand ... (Part 3)

Continuing the previous two postings here is the third set of 5 more "Things politicians need to know about shale gas science", inspired by the recent Guardian article entitled "Top 20 things politicians need to know about science" from an original article in Nature.  

It is not just politicians that need to know this stuff - without it the whole debate is not possible.

11. Seek replication, not pseudoreplication

Results consistent across many studies, replicated on independent populations, are more likely to be solid. There is nothing better than good quality data and lots of it from different locations. Unfortunately data is often man-power intensive and hence expensive. However, government and companies must be prepared to spend money on collecting that data if the general public are to trust their operations (and here).

Moreover, data from different scenarios or locations can often be combined in a systematic review or a meta-analysis to provide an overarching view of the topic with potentially much greater statistical power than any of the individual studies. This requires that data is made freely available between companies and to the general public as well as academics.

Since data is expensive and represents a commercial advantage, companies are not likely to share it or make it available on their own, however enlightened they are. Interestingly Cuadrilla have released a large amount of water quality testing data here and here because they recognise that it represents part of the community patrimony. It is hoped that this will continue. The government should take a central role in coordinating the archiving and publication of all shale gas data through, for example, the British GeologicalSurvey, but is currently avoiding it.

12. Scientists are human

It is not a case of companies bad, politicians bad, activists bad, scientists good – scientists are human too. Although most scientists take extreme care in balancing evidence and following a scientific rationale, a few are less than candid. One must always remember that scientists have a vested interest in promoting their work, often for status and further research funding, and occasionally for direct financial gain. This can lead to selective reporting of results and occasionally, exaggeration. Peer review is not infallible: journal editors might favour positive findings and newsworthiness.

All this adds up to the statement that scientists should not be believed blindly nor their statements regarded dogmatically. If shale gas extraction is to be carried out successfully, it needs the informed consent of the local communities – informed consent means listening to the statements of a range of scientists and others to form a balanced evidence-driven view upon which solid decisions can be made.

13. Significance is significant

Opinion is not important. The only way of testing data is by using valid statistical tests.

One of the most common ways of stating whether an effect, such as whether hydraulic fracturing has contaminated an aquifer, is real is the statistical significance or P-value. The P-value is a measure of how likely a result is to occur by chance. Thus P = 0.01 means there is a 1-in-100 probability that what looks like a link (say fracking and aquifer contamination) actually occurred randomly. We would call P=0.01 very significant as it also indicates that there is a 99-in-100 probability that the link is real. Usually P<0.05 is taken as the limit where a link is considered to be proven.

So far we have no data in the UK that can be used to carry out a test like this because there has been no fracturing where back-ground data is available (no fracking was carried out at Balcombe). Similarly, no background data is available in the USA and so proper statistical tests cannot be carried out there either. However, such tests will be common in future, in the UK at least, because companies are committed to carrying out before and after water quality tests on aquifers.

14. Separate no effect from non-significance

The lack of a statistically significant result (say a P-value > 0.05) does not mean that there was no underlying effect: it means that no effect was detected. A small study may not have the power to detect a real difference. For example, tests of local wild-life around the Balcombe drilling site may suggest that it suffered no adverse effects from disturbance by the drilling operation. Yet if the tests sampled too few animals it would not have the power to detect impacts had there been any. Even then, it would be extremely difficult to distinguish between disturbance by the drilling operations and disturbance by the large number of protestors.

15. Effect size matters

Small responses are less likely to be detected and may fall below the measurement sensitivity of whatever instrument is being used. However, a study with many replicates might result in a statistically significant result but have a small effect size (and so, perhaps, be unimportant).

Let’s take drilling or fracturing induced earthquakes. When hydraulic fracturing is carried out it results in thousands of tiny earth tremors by definition – the whole process is designed to make fractures in the rock and each fracture formation is an earthquake, however small. These earthquakes are mapped in the sub-surface by microseismic methods, and it is possible to see where each one occurs and to delineate the fracture network that forms. If one correlated these earth tremors with the hydraulic fracturing process, there would be, not surprisingly, an extremely significant result -  an apparent smoking gun! However, all of these earthquakes have such a small magnitude that they are never felt at the surface, and are hence unimportant – in fact, a smoking pop-gun!

However, occasionally one earthquake might be big enough to be felt at the surface, but it would not materially alter the significance of the correlation. We must try to correlate problem earthquakes with hydraulic fracturing, but so far there are just too few for this to be possible (only two in the UK, and few in the USA where most of the bigger earthquakes associated with shale gas are not due to hydraulic fracturing, but the irresponsible and thankfully obsolescent habit of disposing of old fracking fluid by deep underground injection).

20 Things politicians should understand ... (Part 2)

Continuing the previous posting here are 5 more "Things politicians need to know about shale gas science", inspired by the recent Guardian article entitled "Top 20 things politicians need to know about science" from an original article in Nature.  

It is not just politicians that need to know this stuff - without it the whole debate is not possible.

6. Regression to the mean can mislead

Extreme patterns in data are likely to be, at least in part, anomalies attributable to chance or error. The next count is likely to be less extreme. There is the tendency in any debate where passions run high and positions are entrenched for either side to grab hold of extreme data and either plug it or lambast it depending on whether it supports their position or not. This is not a rational scientific approach.

The Cuadrilla drilling in Lancashire caused, it is generally agreed, two small earthquakes (magnitudes 2.3 and 1.5). It would not be reasonable to take this observation as being typical of what will happen in all cases of drilling and hydraulic fracturing. In fact, it is likely that most hydraulic fracturing will not cause even earthquakes of this magnitude. On the other hand, if sufficient hydraulic fracturing operations were to be carried out there would be rare occasions when larger earthquakes will be triggered. That is the reason why the government has instituted a traffic light system which sets the threshhold for the freezing of operations at a low magnitude (M=0.5), which is an earthquake that is 32 times smaller than the smaller of the two Lancashire earthquakes and 58 times smaller than the larger.

7. Extrapolating beyond the data is risky

Patterns found within a given range do not necessarily apply outside that range. The range maybe a measurement or may be a location.

In the first case it may simply be that if we calculate that a well corrodes at a certain rate over 1 year, it is not necessarily the case that it will corrode five times as much over 5 years. It might be significantly less! It might me significantly more!!

In the second case, and it should be reasonably obvious, it is not possible to apply observations made in the USA with predicted causes in the UK or elsewhere in Europe, or in fact anywhere other than close to where the original observations were made: The rocks are different, their properties are different, the temperature and pressure is different, the working practices are different and so on.

8. Beware the base-rate fallacy

This is a more technical point. The ability of an imperfect test to identify something depends upon the likelihood of its occurrence (the base rate). For example, an image log (one of the measurement tools that is placed in a well) might be able to identify fractures in the rock with a 99% accuracy, and might identify active fractures in this way, yet it might still be unlikely that the fractures will reactivate when hydraulically fractured.

9. Controls are important

A control group is dealt with in exactly the same way as the experimental group, except that the treatment is not applied. Without a control, it is difficult to determine whether a given treatment really had an effect.

This is really important in understanding most of the existing studies related to hydraulic fracturing. For example, there are no studies of aquifer contamination from the USA where the aquifer water was systematically measured before the hydraulic fracturing started. Hence, it is impossible to say whether any measured contamination after hydraulic fracturing is due to or related to that drilling or whether it pre-existed. That is a fundamental fact of science. Without the initial background levels acting as a control, the post fracturing measurements are meaningless from the point of view of attributing the source of the contamination.

10. Randomisation avoids bias

Experiments should, wherever possible, allocate individuals or groups to interventions randomly. This is a statistical ideal that is difficult to apply in geoscience. We cannot randomly chose a location to do the drilling or hydraulic fracturing because we need to drill where we think there is some chance of success.  It would not be useful, for example, to drill in Brent, where there is no shale gas, despite Brent's recent political posturing.

However, when tests are done, it is important that the companies take account of any reason why their location might not be 'typical' such that it gives odd or extreme values. For example, companies should not drill where there is a known set of major faults, whether they are seismically active or not. In fact it is in the companies' interest not to do this for a whole raft of practical, financial, safety and public relations reasons.

20 Things politicians should understand about shale gas science (Part 1)

In the light of the recent Guardian article entitled "Top 20 things politicians need to know about science" from an original article in Nature, and inspired by it, here are the first five of their points but with particular emphasis on shale gas extraction. But its not just politicians that need to know this stuff - without it the whole debate is not possible.

 

1. Differences and chance cause variation

The real world varies unpredictably. For some branches of science such as physics, the questions may be reduced to very simple experiments whose results are more straightforward to interpret. In Earth Sciences, as in Life Sciences, we cannot simplify the complexity of Nature, and hence scientific results may seem more open to interpretation. The important thing is to recognize that there is a natural complexity and variability and take that into account in the interpretation of scientific observations. There is, for example, a variation of the amount of natural methane in aquifer waters. We need to understand that before we can attribute methane in drinking water to shale gas extraction.

 

2. No measurement is exact

Practically all measurements have some error; and let's be candid here, errors are not bad things but a recognition that there is a limit to what we can do.

Some things cannot be measured very well. Imagine you want to weigh 10 grammes of salt but you only have a 5 kg kitchen scale, the chances are that you might weigh out anything between 1 gram and 50 grammes even if you are careful as can be.

Some things can be measured with incredible accuracy: Arsenic in drinking water can be measured accurately to about 10 parts per trillion! (The US EPA sets its safety threshhold for arsenic in drinking water at 10 parts per billion because it believes that arsenic is cummulatively dangerous at higher levels and it knows it can accurately measure these amounts.)

The good news is that measurement errors can be quantified and quoted easily. You should NOT trust any measurement unless it has an associated measurement error especially if the argument rests on the value of the measurement.

 

3. Bias is rife

Experimental design or measuring devices may produce atypical results in certain circumstances. The corollary is that it is not sufficient to just take the results of a study, but to understand how it was carried out.

For example, a study of gas in drinking water may show that there is more methane within 100 m of a shale gas well. An interpreter (politician, activist, scientist) might then say "shale gas is leaking into the aquifer and contaminating it." This is wrong. There has been no distinction made between thermogenic methane (shale gas, formed at depth by heat) and biogenic methane (naturally occurring methane in aquifers formed at shallow layers by bacteria).

Perhaps if the analysis showed that most of the gas was biogenic (which is actually the case), the interpreter may then say "As the gas is biogenic it was not caused by shale gas extraction." This may also be wrong because the drilling, though not contaminating the aquifer with shale gas from a deep provenance, has disturbed shallow biogenic gas in a way that it has entered the aquifer temporarily.

The results of studies should be carefully studied for interpretation bias.

 

4. Bigger is usually better for sample size

The average taken from a large number of observations will usually be more informative than the average taken from a smaller number of observations. That is, as we accumulate evidence, our knowledge improves. The problem with shale gas is two-fold:

• Most of the concerns come from the practice of shale gas extraction in the USA.
• Almost no scientific studies have been carried out there, although the situation is slowly improving, most opinion is not based on evidence.

It is extremely irresponsible to extrapolate the US situation to the UK and other parts of Europe for a number of reasons (population density, different shales, regulation and data gathering). There is already more high quality independent publicly available scientific data from the few wells drilled in the UK than for all the thousands of wells in the States. That is a result of the responsible attitude of the companies and government protection agencies. We need public overview to ensure that it continues.

 

5. Correlation does not imply causation

It is tempting to assume that one pattern causes another. However, the correlation might be coincidental, or it might be a result of both patterns being caused by a third factor – a “confounding” or 'lurking' variable. For example, it is tempting to believe that methane exists in aquifers because of shale gas drilling, and it is important to find out if that is true. However, we have already seen that an inability to discriminate between two types of gas (thermogenic and biogenic) can lead to misinterpretation, and acts as a 'lurking' variable.

Early studies in the US were not very good because they had not measured the methane in aquifers before shale gas extraction started and hence could not be sure that what they were measuring was natural or as a result of the drilling. These studies relied on the association of a rise in groundwater methane close to wells (other more recent studies have also found the opposite).

However, even if it were true that there is a correlation between well position and high levels of groundwater methane it does not imply that the drilling caused the groundwater gas concentrations. It may simply be that the wells were placed to extract shale gas at a position where gas has been reaching the surface naturally for millions of years. In other words, a well placed well.

In this example correlation does not imply causation, though:

• causation may exist too - more study needs to be carried out if this is suspected, and
• if gas has been reaching the surface naturally (not caused by the drilling), how is this the case? Are there natural pathways, fractures and faults that ease the transport of the gas? A responsible producer would be using science to have the best solution to these questions to ensure that the drilling operations did not exacerbate the effect.

The Price of Energy

The government has tried to explain how shale gas might reduce the price of energy. On the 19th of July 2014 the Chancellor George Osbourne said:

“I want Britain to be a leader of the shale gas revolution – because it has the potential to create thousands of jobs and keep energy bills low for millions of people.”

Many commentators including this blog have shown how unlikely that is.

However, shale gas could easily stop the incessant rise in energy prices by using shale gas revenue to support the development of green alternatives. 





What we saw at Balcombe was in some ways a triumph of free expression, responsibility, regulation and control. 

• The police guaranteed that protestors could express their opinions while upholding the rights of others. 
• Cuadrilla has shown a remarkably responsible approach to the development, especially in their lack of inflammatory language and their preparedness to consider and comission independent scientific measurements of the environment. 
• The responsible attitude was matched by the Balcombe Parish Council, whose report on the exploration before it started is a fine example of evidence-based pragmatism delivered in a clear way. I look forward to a summary report in about a year or so that describes their experience of all aspects of the exploration.
• The Environmetal Agency applied the existing regulations and control in what seems to be a fair and balanced manner, taking account of environmental sensitivities and recognising pragmatic approaches when necessary. Even after the  fact the Environmental agency are having meetings with the local residents to see if they can communicate and inform better.

The price of energy is an environmental issue, but it is also one of government policy, and a decision the government could make with very little delay is to pledge at least to stabilise energy prices for 5 years by using shale gas revenues.

Issue 13: Can the disposal of waste fracking fluids by underground injection cause earthquakes

Yes. These earthquakes have been more problematic and dangerous than earthquakes associated with hydraulic fracturing itself. However, disposal of waste fracking fluids in the UK is extremely unlikely and recycling of fluids is becoming the norm.

On Wednesday (4th September 2013) NBC News reported that scientists had linked 109 earthquakes in Ohio to hydraulic fracturing. 

What happened?

NBC reports that "...the earthquakes were never very powerful and caused no serious injuries or damages". However, the fact that they occurred in a region not known for seismicity was an indicator that they might be linked to human activity. The largest (shown in the image) was about magnitude 4, but the others were all much smaller. Counting the number of earthquakes is therefore a misleading statistic if we want to judge the impact of a set of earthquakes.

The earthquakes were caused by the injection of waste hydraulic fracturing fluid into a deep disposal well.

In fact Ohio has 177 wells into which it pours waste water from diverse sources. The practice is highly dangerous if it is carried out without a proper understanding of the local geology and if the volumes and fluid pressures are not well regulated. That seems to be what has happened here.
 

The largest Ohio earthquake (Courtesy of USGS)

The earthquakes were only associated with one of the 177 waste water disposal wells and although that was probably disposing of waste hydraulic fracturing fluids, the earthquakes were not related to the processes of  shale gas exploration, drilling or hydraulic fracturing itself. The scientists noted that since only this one well was linked with seismic activity, the capability of waste water injection to cause earthquakes was rare. 

But not that rare. The previous week residents in Greenbrier, Arkansas settled a suit for minor damages caused by earth-quakes triggered by under-ground injection of waste water.

The disposal of waste fracking fluids by underground injection is currently unregulated in the USA, although the EPA have said that rules will be in place by 2014. It is, actually, rather important. The largest earthquake ever recorded in Oklahoma occurred in 2011, as one of a pair with magnitudes 4.7 and 5.6, which were caused by waste fluid injection. There were two injuries, 14 buildings were destroyed and others damaged together with a road. 

The Oklahoma earthquake (Photograph by Sue Ogrocki, AP)

There is no guarantee that larger earthquakes due to waste water injection will not occur if the procedure is not tightly regulated. This is because the waste water injection is only the trigger to the earthquake; the size of the earthquake itself depends upon the amount of stored energy in the stressed fracture prior to triggering.

In fact the problem may be resolving itself. In Europe the intention is to recycle all fracking fluids. Even in the USA, there has been a steady swing away from the injection of waste fracking fluids for disposal towards recycling. Currently, fracking fluid is treated and then reused in other fracking jobs, but the technology exists to transform the fracking water into water that meets the standards required for being released back into the surface water.

Could earthquakes caused by waste water injection happen in the UK?

No. 

• Unregulated injection of any fluid for disposal is not allowed under UK and EU regulations. The chances of obtaining permission to do so with ordinary water would be almost zero, and it would never be considered for waste fracking fluids, especially as they can be efficiently recycled these days.
• Geophysicists have known for a very long time that fluid injection can cause earth tremors. It should never be carried out without mapping local major faults and monitoring the back-ground seismicity, and should never exceed certain volumes and fluid pressures. This is all taken account of in the UK regulations and practices associated with shale gas.
• The UK recommendations are that all processes should be stopped if an event greater than magnitude 0.5 occurs. This level is about five million times less destructive than the largest of the Ohio 'quakes based on energy release.

Does that mean no earthquakes from shale gas and fracking in the UK?

No. 

If there is development of the shale gas industry in the UK, I would still expect there to be a small increase in the number of small (less than magnitude 2) earth tremors associated with the fracking process. 

These tremors will not result in damage to property or injuries, and it is very unlikely that you will ever feel one.

Coal vs. Gas II: A perspective

Just how many premature deaths are there in the UK each year from pollution caused by coal-fired power stations? 

Greenpeace says the death toll was 2115 in 2010, which is slightly smaller than deaths due to road traffic accidents (2337).

In 2011, Balcombe had a population of 1424. 

Hence, coal deaths per year in the UK are the equivalent of wiping out Balcombe and its rural neighbours, and then doing it again in each subsequent year.

Diagram from the Greenpeace report "Silent Killers".

Premature winter deaths are even bigger (25,875 per year). That is the equivalent of wiping-out Haywards Heath (pop. 25,550 in 2006) next year! At that rate we can depopulate East Sussex (pop. 795,800 in 2012) in 30 years.

But what does it matter - these people were going to die anyway providing we do nothing. But if we did replace coal generation by gas and made some of the gas freely available for the exposed parts of our society, may be we could save at least some of these lives.

Coal vs. Gas Revisited

In June The Guardian reported on the release of an important Greenpeace report on coal-fired power generation. The summary made shocking reading:

"Air pollution from Europe's 300 largest coal power stations causes 22,300 premature deaths a year and costs companies and governments billions of pounds in disease treatment and lost working days" 

In fact a total of 240,000 years of life were said to be lost in Europe in 2010 with 480,000 work days a year. 

The UK was Europe's fifth most coal-polluted country in 2010, with 22,600 "life years" lost. Drax, Britain's largest coal-powered station, was said to be responsible for 4,450 life years lost, while Longannet in Scotland was said to be responsible for 4,210 life years lost.

The Greenpeace report is not scaremongering. In fact it is in line with studiesdone in the USA and previously reported in this blog. 

Greenpeace would like to replace coal with renewables, which is frankly impracticable. If, for example, we switched our coal generation to wind, it would require 851,000 5 MW windmills working flat-out all year. And that does not consider their effect on our environment, the radioactive and chemical pollution they cause in China, the lack of constant wind (except in some parts of the Houses of Parliament) and the lack of space for such a number of mills.

By contrast shale gas is a known, practicable, increasingly well regulated and greening industry. There are many reasons why we should produce shale gas, not the least of which is the saving of life and living potential that switching coal generation to gas generation would bring.

I would suggest we

·         produce shale gas,

·         compensate the PIMBYs,

·         tax the companies,

·         use revenues to boost the energy saving and renewable energy developments, as well as

·         making gas-fired power and heating available free to all families with children under 10 as well as those over the age of 70. 
 

Then we’ll improve social justice, save lives from coal pollution, reduce premature winter deaths (about 24,000 per year) significantly, and reduce our greenhouse gas emissions. 

Do nothing and coal-fired generation and pollution will go up as a result of imported coal (unwanted coal from the USA ironically), energy efficiency and renewable development will limp along, green-house gas emissions will continue to rise, and we will carry on trying to avoid thinking about the annual winter death toll.

Pimbys have been spotted in Balcombe?

It was bound to happen.

Sixty of the residents of Balcombe are protesting against the shale gas protestors. After weeks of leaving the protestors their right to peaceful protest, some Balcombe residents have had enough. 

In an anonymous letter they express their "strong disapproval of the recent & continuing protests", while not believing that "exploratory drilling or properly regulated further exploitation will unduly damage our environment".

Are these people a rare sighting of that friendly, timid but stubborn bird, the PIMBY, with its mellifluous call which sounds something like "Please in my back yard"! 

Cynics have said that, with the promise of parish councils benefitting in cash from drilling and production, the PIMBY is thinking about feathering its nest. 

I prefer the simple explanation that common sense, as exemplified by the Balcombe Parish Council's clear evidence-based report on fracking, will win out in the end for the good of all. Farmers that have been shown around oil and gas production facilities in Canada return home as converts; not because they have been bribed with money, but because they have been shown it as it actually is, and not how extreme shalegasophobes paint it.

Importantly the authors warn "Let other communities be warned that our hitherto friendly village has suffered not only from the protesting crowds but prior to that from the intemperance of self-appointed  “ activists”, unfair abuse of our Parish Council, politicisation of the village fete, unsightly banners and, above all, spreading of unwarranted fear." 

How many other parish councils will be reading this with trepidation, I wonder?

The authors' plea has gone out for "the Government, Local Authorities & the Industry to provide clear and easily understood  information on the rationale for developing a British shale oil & gas industry".

We, of course, try to do that in this blog, and all concerned academics ought to be part of the dissemination of such understanding. In particular, the call for public disclosure of data to the Prime Minister, and its follow-up, and in the Issues raised and discussed in the blog (e.g., earthquakes).

Issue 12: Fracking pours thousands of gallons of acid into the earth

Yes. This is completely true. The acid is designed to react with the rock in order to make it easier to create fractures. The acid is completely used up in that process. Problems would arise only if there were a spillage of the acid at the surface or near the aquifer.

Hydrochloric Acid

It is often said that thousands of gallons of hydrochloric acid are in fracking fluid. This is sometimes the case. If the shale that is to undergo hydraulic fracturing contains a reasonable proportion of calcite or dolomite, it is very likely that hydrochloric acid will be used to help the fracking process. Indeed it is sometimes used without fracking.

Hydrochloric acid  (HCl), the acid found in your stomach, reacts with the calcite  (CaCO₃) in limestone to give Calcium Chloride (CaCl₂), water and CO₂. The breakdown of calcite to calcium chloride promotes fracture formation and the CO₂ adds to the pressure of fluid in the fractures. Although a lot of HCl is put down-hole, because there is so much calcite, all of the acid is turned to water and CO₂.

The process is similar if there is dolomite in the rocks, with water and CO₂ being produced, but this time with CaCl₂ and MgCl₂. 

Hydrochloric acid is usually used in a 15% by weight solution. In this form, 5000 litres of HCl will react fully with 1.1 tonnes of calcite, which is about 0.4 m³ of that mineral. However, the well is surrounded by millions of cubic metres of calcite containing rock. Hence, although the acid volumes seem large, they are actually quite small compared to the rock's ability to neutralise it, and the acid is completely used up in the process.

Does that mean its safe?

Largely, Yes. All the acid reacts to form water and CO₂, which stay in the reservoir or are recouped in the flow-back fluid.

However, there is a small chance that some of the initial acid might be involved in a surface spill. Rigorous procedures should be put in place to avoid this, and UK regulations are already in place. However, if a spill occurs it is unlikely to affect a large area because soil is extremely good at buffering acids.

Other Acids

In fact hydrochloric acid is not the only acid to be used in the acidification during hydraulic fracturing. 

Other acids include Acetic acid (CH₃COOH, vinegar, 10%), Formic acid (HCOOH), Hydrofluoric acid (HF, 3% usually with HCl) and sulphamic acid (H₃NSO₃).

The first two are relatively mild and tend not to corrode steels, aluminium or chrome plate at well temperatures and pressures. 

By contrast, hydrofluoric acid is extremely dangerous and can eat glass, cause flesh burns that are painless and extreme, and interact with calcium in the blood leading to cardiac arrest. It is one of the most nasty chemicals of which I know. We impregnate rocks with epoxy and then place them in HF for the acid to eat the rock away leaving the epoxy showing where the pores are and how interconnected they are. Hydrofluoric acid reacts very quickly and should not be used in limestones, but only in sandstones. In fact it is hardly ever used in Europe.

Sulphamic acid is probably better for the environment because it can be brought to the well-head in a powder form, which reduces the liklihood of surface spills. However, it is only about a third as effective as hydrochloric acid (volume per volume) and is correspondingly more expensive to use.

In summary, acid (usually hydrochloric) is part of the fracking mix. However, it poses no danger to the environment because it is all used up in the process of making the fractures. The only slight concern is for surface spills, which are rare and fully covered by UK regulations,.

Wind, shale gas, HS2, badgers and the Aarhus Treaty

(28th August 2013) According to The Independent:

"The United Nations Economic Commission Europe has declared that the UK flouted Article 7 of the Aarhus Convention, which requires full and effective public participation on all environmental issues and demands that citizens are given the right to participate in the process."

The Aarhus Convention (in full here in English, in full here in many other languages) aims in its 22 Articles 

"...to contribute to the protection of the right of every person of present and future generations to live in an environment adequate to his or her health and well-being, each Party shall guarantee the rights of access to information, public participation in decision-making, and access to justice in environmental matters in accordance with the provisions of this Convention."

It is becoming clear that the UK government has not ensured that every person has been given access to information about wind farms or been able to partcipate in the decision-making process from an environmental point of view. We will see what impact the ruling has.

The big question is whether the Aarhus Convention applies to other current environmental issues.

Shale gas 

The Convention does not explicitly cover the production of oil or gas (See Annex 1 of The Convention), which is too much of an oversight to be other than deliberate. It does, however cover oil and gas refineries and installations for gasification and liquefaction. It may cover those plants which gather shale gas together before pushing into a gas pipe network.

However, The Convention does cover groundwater abstraction where the annual volume of water abstracted is equivalent to or exceeds 10 million cubic metres and also covers pipelines for the transport of gas, oil or chemicals with a diameter of more than 800 mm and a length of more than 40 km.

Moreover, The Convention does state (Annex 1, Paragraph 20) that any activity not covered by paragraphs those activities that are mentioned explicitly in Annex 1, but where public participation is provided for under an environmental impact assessment procedure in accordance with national legislation, fall also under the Aarhus Convention.

HS2

The Convention covers explicitly "Construction of lines for long-distance railway traffic".

Badgers

Unfortunately for badgers, not only has The Convention nothing to say about the management of wildlife, it contains an exclusion for short-term research and development under which current badger culling would probably fall.

In summary, we have a UN Convention, to which the UK is fully signed-up, that guarantees "rights of access to information, public participation in decision-making, and access to justice in environmental matters".  

In my view that means plentiful, accessible and factually accurate data and interpretation backed-up by scientific research, together with procedures to ensure public participation. This goes further than the recent call for public disclosure on shale gas developments that was made to the Prime Minister and its follow-up.