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Are we closing off technology options for a low carbon future?

Mike Stephenson, British Geological Survey


In a now famous article in the journal Science, Pacala and Socolow introduced the scientific world to the concept of ‘stabilization wedges’. These are units by which we could measure the amount of effort we’ll need to tackle global warming - while still keeping the lights on. Several of these wedges are needed to get from the ruinous ‘business as usual’ high-CO2 emissions scenario to one where we might reduce global warming to a manageable level.

One of Pacala and Socolow’s wedges consisted of converting coal power plants to gas - in other words to make gas the provider of electricity baseload, rather than coal. They said that to achieve a ‘wedge of carbon abatement’ you could switch 1400 GW worth of 50%-efficient coal plants to gas power stations. This suggestion was rather far-sighted in that it predicted today’s discussions about the potential for natural gas - and particularly shale gas - to provide a lower carbon fossil fuel alternative. Switching from coal to natural gas saves carbon because burning gas in power stations is about half as CO2-polluting as burning coal.


But another wedge they suggested was to introduce widespread carbon capture and storage (CCS) on gas and coal power stations. This is where the CO2 from the power stations is buried out of harm’s way deep in geological formations. CCS has been taken up as Government policy in several countries (for example in Britain), though no large-scale CCS yet operates here. A third suggested wedge was to double the amount of global nuclear power.


But is gas - whether conventional gas or shale gas - really a low carbon fuel? At the moment this question is difficult to answer. There have been relatively few studies and the ones that have been published have been challenged. A recent report for the European Commission (AEA Technology, Climate Impact of Potential Shale Gas Production in the EU) concludes that shale gas compares rather favourably in terms of its overall carbon footprint with conventional gas, particularly if the shale gas is ‘home grown’ and is competing with conventional gas that is imported. This is because of the emissions related to transporting and liquefying imported gas. The effects of substituting gas for coal in countries whose electricity supply is dominated by coal power stations can be radical. For example if Poland switched from coal to gas a 41-49% reduction in CO2 emissions would result. If carbon capture and storage was employed on such gas power stations the emissions would drop even further.


However the chance to develop shale gas and other low carbon wedges is being jeopardised not by their technical feasibility but by their image amongst the public and investors.


The public dialogue on shale gas is becoming increasingly hysterical and irrational. Recent views of shale gas suggest that Blackpool might disappear beneath the Irish Sea because of fracking, or that the Mendips Hills will become volcanoes. Neither of these have any scientific basis.  There are also widespread though less extreme views about the safety of CCS and geological disposal of nuclear waste. Views like these diffuse into the general discourse and become the currency of discussion, lowering the quality of the debate and risking bad decisions and faulty policy. This is not to say that there aren’t scientific concerns about for example methane contamination of water supplies or small earthquakes caused by fracking. But the proper business of science in deciding whether gas (methane or CO2) might leak out of the ground is distracted by ridiculous questions that don’t need answering.


But if these geo-engineering wedge technologies aren’t seen as feasible it will be harder and more expensive to achieve the emissions targets we’ve set - and other ‘wedges’ will have to take the strain. In short we may lose technologies that could act as bridges to a lower carbon future.


Most geologists and technologists are confident that shale gas, CCS and nuclear waste disposal can be done safely, and the weight of scientific evidence in these new areas backs these views up. But the science still needs to be seen to be independent and peer-reviewed and it needs to be communicated! Scientists are not naive enough to believe that the results of scientific experiments enter the public consciousness, but their conclusions can, by slow diffusion, improve the quality of public and policy debate so that the right decisions can be made. The public and policy makers, in turn, need to know that science can be rather a slow process, and that single studies may yield ambiguous results. Also they should know that the spectacle of seeing scientists disagree and argue is a sign of progress, not a basis to distrust them.


Having the public (and investor community) on the side of low carbon geo-engineering technologies will help to keep our technology options open. Improving the quality of public debate is helped by doing the right science at the right time, keeping it independent, and communicating it well. This will help to keep the lights on while also meeting emissions targets and keeping global warming at bay.

Head of Science and Energy at the British Geological Survey

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Q&A: What are tax credits and how do they work?

All you need to know about the government's plan to cut tax credits.

What are tax credits?

Tax credits are payments made regularly by the state into bank accounts to support families with children, or those who are in low-paid jobs. There are two types of tax credit: the working tax credit and the child tax credit.

What are they for?

To redistribute income to those less able to get by, or to provide for their children, on what they earn.

Are they similar to tax relief?

No. They don’t have much to do with tax. They’re more of a welfare thing. You don’t need to be a taxpayer to receive tax credits. It’s just that, unlike other benefits, they are based on the tax year and paid via the tax office.

Who is eligible?

Anyone aged over 16 (for child tax credits) and over 25 (for working tax credits) who normally lives in the UK can apply for them, depending on their income, the hours they work, whether they have a disability, and whether they pay for childcare.

What are their circumstances?

The more you earn, the less you are likely to receive. Single claimants must work at least 16 hours a week. Let’s take a full-time worker: if you work at least 30 hours a week, you are generally eligible for working tax credits if you earn less than £13,253 a year (if you’re single and don’t have children), or less than £18,023 (jointly as part of a couple without children but working at least 30 hours a week).

And for families?

A family with children and an income below about £32,200 can claim child tax credit. It used to be that the more children you have, the more you are eligible to receive – but George Osborne in his most recent Budget has limited child tax credit to two children.

How much money do you receive?

Again, this depends on your circumstances. The basic payment for a single claimant, or a joint claim by a couple, of working tax credits is £1,940 for the tax year. You can then receive extra, depending on your circumstances. For example, single parents can receive up to an additional £2,010, on top of the basic £1,940 payment; people who work more than 30 hours a week can receive up to an extra £810; and disabled workers up to £2,970. The average award of tax credit is £6,340 per year. Child tax credit claimants get £545 per year as a flat payment, plus £2,780 per child.

How many people claim tax credits?

About 4.5m people – the vast majority of these people (around 4m) have children.

How much does it cost the taxpayer?

The estimation is that they will cost the government £30bn in April 2015/16. That’s around 14 per cent of the £220bn welfare budget, which the Tories have pledged to cut by £12bn.

Who introduced this system?

New Labour. Gordon Brown, when he was Chancellor, developed tax credits in his first term. The system as we know it was established in April 2003.

Why did they do this?

To lift working people out of poverty, and to remove the disincentives to work believed to have been inculcated by welfare. The tax credit system made it more attractive for people depending on benefits to work, and gave those in low-paid jobs a helping hand.

Did it work?

Yes. Tax credits’ biggest achievement was lifting a record number of children out of poverty since the war. The proportion of children living below the poverty line fell from 35 per cent in 1998/9 to 19 per cent in 2012/13.

So what’s the problem?

Well, it’s a bit of a weird system in that it lets companies pay wages that are too low to live on without the state supplementing them. Many also criticise tax credits for allowing the minimum wage – also brought in by New Labour – to stagnate (ie. not keep up with the rate of inflation). David Cameron has called the system of taxing low earners and then handing them some money back via tax credits a “ridiculous merry-go-round”.

Then it’s a good thing to scrap them?

It would be fine if all those low earners and families struggling to get by would be given support in place of tax credits – a living wage, for example.

And that’s why the Tories are introducing a living wage...

That’s what they call it. But it’s not. The Chancellor announced in his most recent Budget a new minimum wage of £7.20 an hour for over-25s, rising to £9 by 2020. He called this the “national living wage” – it’s not, because the current living wage (which is calculated by the Living Wage Foundation, and currently non-compulsory) is already £9.15 in London and £7.85 in the rest of the country.

Will people be better off?

No. Quite the reverse. The IFS has said this slightly higher national minimum wage will not compensate working families who will be subjected to tax credit cuts; it is arithmetically impossible. The IFS director, Paul Johnson, commented: “Unequivocally, tax credit recipients in work will be made worse off by the measures in the Budget on average.” It has been calculated that 3.2m low-paid workers will have their pay packets cut by an average of £1,350 a year.

Could the government change its policy to avoid this?

The Prime Minister and his frontbenchers have been pretty stubborn about pushing on with the plan. In spite of criticism from all angles – the IFS, campaigners, Labour, The Sun – Cameron has ruled out a review of the policy in the Autumn Statement, which is on 25 November. But there is an alternative. The chair of parliament’s Work & Pensions Select Committee and Labour MP Frank Field has proposed what he calls a “cost neutral” tweak to the tax credit cuts.

How would this alternative work?

Currently, if your income is less than £6,420, you will receive the maximum amount of tax credits. That threshold is called the gross income threshold. Field wants to introduce a second gross income threshold of £13,100 (what you earn if you work 35 hours a week on minimum wage). Those earning a salary between those two thresholds would have their tax credits reduced at a slower rate on whatever they earn above £6,420 up to £13,100. The percentage of what you earn above the basic threshold that is deducted from your tax credits is called the taper rate, and it is currently at 41 per cent. In contrast to this plan, the Tories want to halve the income threshold to £3,850 a year and increase the taper rate to 48 per cent once you hit that threshold, which basically means you lose more tax credits, faster, the more you earn.

When will the tax credit cuts come in?

They will be imposed from April next year, barring a u-turn.

Anoosh Chakelian is deputy web editor at the New Statesman.