With respect to fracking, earthquakes are the least of our worries. Fracking involves drilling 1,800 metres down, then horizontally the same distance. Water, sand and chemicals are forced down the hole, the pressure splitting the shale and releasing the gas. The gas forces 40 per cent of the liquid back up the shaft, now contaminated with volatile chemicals and harmful carcinogenic metals.
The really negative effects come from contamination of water and soil, as seen in Pennsylvania in 2010: sick animals and people, contaminated crops and air pollution. The promised job creation will be outweighed by job losses in agriculture and tourism: crops will be blacklisted, property devalued and landscapes scarred.
An outright ban on fracking, as in France and Germany, is the only sensible answer.
Enniskillen, Northern Ireland
Lord Browne, the former head of BP and now head of Cuadrilla, has joined a list of powerful individuals who have been persuaded by the fossil-fuel lobby that shale gas is the answer to the world's future energy needs ("Fracking could bring UK 50,000 jobs", says Browne, 26 March).
President Obama stated in his State of the Union address in January: "We have a supply of natural gas that can last America nearly 100 years, and my Administration will take every possible action to safely develop this energy. Experts believe this will support more than 600,000 jobs by the end of the decade."
Osborne followed suit in his Budget statement: "Gas is cheap, has much less carbon than coal and will be the largest single source of our electricity in the coming years."
The problem with shale gas is that fracking results in atmospheric releases of methane twice that encountered with conventional gas. Methane is a powerful greenhouse gas with a global-warming potential seven times greater than carbon dioxide over a 20-year time frame.
For shale gas to be environmentally friendlier than other fossil fuels, it is necessary to keep methane emissions from fracking below 2 per cent. Current operations release about 10 per cent and in the US the fossil fuel industry is strenuously resisting methane control legislation. It appears that they have the key politicians on their side.
Dr Robin Russell-Jones
Stoke Poges, Buckinghamshire
There are hundreds of documented cases in the US of shale gas fracturing leading directly to water contamination, in some cases so severe that domestic water supplies became flammable.
If there's even a tiny chance of this happening in the UK, I would expect the Department for Energy and Climate Change to imprison those responsible.
Tax breaks for donations to charity
The argument that high earners don't pay enough tax because they use loopholes such as making donations to charity is flawed.
The Government collects tax so that it has money to run the country. The taxes that people pay are their contributions to the running of the country. Running the country includes paying for medical research, education, supporting the elderly and the disabled, and providing foreign aid. Charities also pay for medical research and education, support the elderly and the disabled, and provide foreign aid.
When people donate money to charity, they are still contributing to the running of the country, albeit directly rather than via the Chancellor, and to say that they are avoiding paying tax is a red herring. Contributions to the Exchequer and contributions to charities should be taken together to evaluate whether an individual is making a fair contribution to running the country.
I've heard many times that our income tax system is too complicated. For the vast majority of us this isn't true; we receive our income net of PAYE taxation and it is our money, to do with what we like, including donating to charities, which most do generously. Our deducted taxes are used by our elected government to fund public services, including making grants to charities, and if we don't like what they do we can pressurise them to change their minds or replace them at the next election.
I don't recall ever being asked if I would like to pay more tax so that a number of very wealthy taxpayers could use some or all of their tax liability to fund their favourite causes rather than contributing to the cost of the NHS, education, armed forces etc, which must then rely on the rest of us paying up.
Geoff S Harris
Could the word "'philanthropist" perhaps be reserved for those who donate to charities as well as (not instead of) paying their fair share of tax?
Postal voting open to fraud
Reading John Spellar's claim (letter, 17 April) that alleged postal vote fraud amounted to only 16 cases out of 5 million, I was instantly reminded of the claim that phone-hacking was all the work of one lone reporter. Since the rest of those postal votes were not investigated, absence of proof of fraud is not proof of absence.
With 25 per cent of votes cast by postal ballot, the system is wide open to abuse and the election in each and every marginal constituency on which the balance of power in the House of Commons rests is severely compromised. Mary Ann Sieghart (16 April) is right that postal voting destroys the very notion of the secret ballot and is a grave threat to democracy.
Keighley, West Yorkshire
In the interests of democracy, Mary Ann Sieghart's article on postal voting is spot on. Every voter should register individually and be required to turn out unless disabled or otherwise unable to vote in person. I vividly recall, while canvassing for the SDP in Slough in 1983, the aplomb with which Asian men, in particular, felt able to vouchsafe the support of the entire household.
Reasons to take out tonsils
Jeremy Laurance (6 April) lists tonsillectomy as an "out of date op". The Cochrane review of the best quality trials of surgery for sore throats states that tonsillectomy is effective in reducing the number of episodes of sore throat and days with sore throats in children. Moreover, the government (HES) statistics show that over the past five years as fewer tonsillectomies have been performed there has been a 40 per cent increase in hospital admissions for the often debilitating complications of tonsillitis and quinsy.
In addition to its role in children with sore throats, tonsillectomy can also be a potentially lifesaving operation in children with obstructive sleep apnoea, and tonsillectomy is a vitally important operation in the diagnosis of potential throat cancer in adults who have persistent sore throats that don't get better, or one tonsil larger than the other – particularly if they have smoked.
Jonathan C Hobson
Consultant ENT / Head & Neck Surgeon, Warrington & Halton Hospitals NHS Trust
Race bias in school lessons ignored
Yes, Lord Macpherson accused the Metropolitan Police of "institutional racism and demanded urgent remedial action" (report, 8 April). But he went further than that. After some correspondence with me (and undoubtedly many others) about the sources of racism, he made three specific recommendations in his report: "That consideration be given to amendment of the National Curriculum aimed at valuing cultural diversity and preventing racism, in order better to reflect the needs of a diverse society".
I had suggested to Judge Macpherson that a school curriculum which ignored the histories/ achievements of any but the British (and the Greeks and Romans) induced feelings of superiority. Altering the curriculum would affect the endemic racism in Britain. The judge's recommendation has been ignored.
Vice-chair, Black and Asian Studies Association, Oare, Kent
Your "Budget in Brief" article entitled "Osborne claim over wildlife costs 'baseless' " (23 March) states that 99.5 per cent of developments are unaffected by Habitats regulations. That percentage is derived from the number of development proposals (0.5 per cent) that Natural England formally objects to.
In his Budget statement, the Chancellor was not alluding to objections to development, rather the time and cost of complying with a complicated, un-coordinated regulatory regime, involving local planning authorities and often multiple government agencies. Natural England does not object to the vast majority of developments that have to comply with the Habitats Regulations. It is the compliance that is costly.
Jaquelin C Fisher
Chairman, JFA Environmental Planning, London SW12
Lib Dems' principles
Having worked for the Liberals and Lib Dems for nearly as long as Derek J Cole (letter, 11 April), including two general election contests, I can sympathise with his disillusion with the Lib Dems in coalition: the volte face over tuition fees, the debacle in the voting reform referendum, the support for the unpopular Health Service reforms etc.
However, he is wrong on two counts. First the policies and principles which we believed in and for which we fought will never be found in the Labour Party, and, second, the prospectus was not false, only the implementation was maladroit.
While the increase in the cover price of the The Independent to £1.20 from 23 April is not unexpected and is to be regretted, you are to be congratulated for your prominent letter to readers (17 April) explaining the reasons for the price rise. So often in the past there has been no advance notice of such increases, just a very small paragraph on an inside page on the day the increase comes into effect. I hope that such transparency on your part will be rewarded by loyal readers keeping faith with you.
It is the media that decides what is news and what pictures to print. It is the media that fuels our appetite for a story. I find it deeply disturbing when a killer like Anders Breivik is given the platform he craves by a press selling blood and gore. He is pictured everywhere displaying a symbol of fascism. A major rethink is needed for a 21st-century media when so many more people crave attention.
Great Missenden, Buckinghamshire
In "Animal artist has roar talent" (13 April) Matilda Battersby shows ignorance of the technique of crochet. Needles are not used, but instead a crochet hook, so there can't be a "clacking of crochet needles".
Dinas Powys, Vale of Glamorgan
"The 50 Best Menswear" (The Information, 14 April). Not a thing for anybody over 15. Thanks.
Todmorden, West YorkshireReuse content