This seems a mistake. A large section of the population of the US and the UK, and smaller numbers elsewhere, believe that the apparent scientific consensus on global warming is a result of selective coverage by TV and press. The failure to cover presentations by some of the leading sceptics is support for the accusation that global media, and mainstream climate scientists, are refusing to engage with the dissenting views of reputable scientists who do not share the standard view.

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Roy Spencer is one such scientist. He has good scientific credentials and his sceptical book on climate change is selling extremely well in the US. The main theme of his presentation was that climate sensitivity to increases in CO2 is much less than conventionally thought. He doesn’t deny the human sources of climate change; he suggests that the standard models exaggerate the impact of greater amounts of CO2 in the atmosphere because they fail to comprehend the true impact of changes in cloud cover. In summary, he says that changes in cloud cover may damp temperature changes resulting from CO2 increases, rather than exaggerate them.

The scientific consensus is that doubling the amount of CO2 and other GHGs in the atmosphere will, if all other things remain equal, increase temperatures by about 1.2 degrees Celsius. In the standard models, this increase is multiplied by two or three because of the effects of changes in cloud cover. These reinforcing effects are usually called ‘positive feedbacks’. Other positive feedbacks include higher temperatures decreasing the amount of ice cover, causing less light radiation to be re-emitted to space.

Why is it generally thought by climate modellers that changes in cloud cover will amplify the effect of the CO2 increase? There are two forces at work:

• High-level cirrus clouds act as a blanket around the earth, trapping heat. A generally hotter atmosphere is generally assumed to increase the amount of cirrus cover.
• Low-level clouds reflect the sun’s light back into space tending to decrease temperatures. Global warming is usually thought to result in decreased low cloud cover, amplifying the effect of warming.

Sir John Houghton’s standard undergraduate textbook on global warming says that ‘climate is very sensitive to possible changes in cloud cover or structure’. In other words, if the standard models are even slightly wrong about the nature of the relationship between clouds and warming, changes in cloud cover may amplify or repress the temperature variations induced by greenhouse gas increases.

Scientists often talk about the global warming impact of greenhouse gases in terms of watts (which can be thought of as a unit of heat) per square metre. This measure is usually called ‘radiative forcing’. The IPCC analysis suggests that the man-made greenhouse gases will increase the radiative forcing by about 4-5 watts per square metre by 2050. Houghton’s book says that forcing by clouds is typically a many times multiple of this. It varies by latitude and by time of year. But the crucial point is that clouds matter a great deal.

As I’ve said, the standard view is that clouds amplify the impact of global warming induced by CO2. Houghton says that there is ‘encouraging agreement’ between this hypothesis and actual observations of cloud behaviour. Roy Spencer’s presentation asked us to consider two pieces of work from his team that tend to contradict this view:

• A 2007 paper that suggested that tropical rainstorms result in only short-term increases in high-level cirrus clouds that dissipate quickly. (Cirrus acts as a blanket.) Spencer used temperature and other readings collected by satellite.
• A paper waiting for publication that says that the theory that higher temperatures reduce low cloud cover is inadequate. (Low clouds tend to reflect sunlight back into space.) He says that the causality may be different. Perhaps lower levels of cloud cover result in higher surface temperatures, a phenomenon that we might all instinctively recognise? He claims that previous measurements have simply assumed a causality that sees higher temperatures reducing the coverage of low clouds. He says we haven’t done the measurements properly to ascertain which comes first, higher temperatures or lower cloud cover.

What if Spencer is right? His work suggests that a doubling of CO2 levels from pre-industrial levels – which will occur some time around 2075 if today’s rate of increase persists – will not result in temperatures three or four degrees above pre-industrial levels, as pessimists fear, but perhaps about one degree.

We have already seen about 0.7 degrees, with greater increases in high latitudes. So his theory implies strong negative feedback from now on. As Roy Spencer said in his presentation, the world is engaged in a huge experiment to determine the true sensitivity of climate to changing greenhouse gas levels. His view on the outcome of that experiment is strikingly different to the world’s academic consensus and it would be good to have a rebuttal from those who disagree with him.

Note
Dr Spencer was one of the scientists who reported some years ago that the troposphere was not warming. His research findings were undermined by further analysis of the data that his team had collected. Almost all scientists now believe that the degree of tropospheric temperature change is broadly compatible with the standard model of global warming.

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Conventional DECT (‘cordless’) phones consume about 2 watts when the battery is charged and 3 watts when charging. The large number in UK homes, all on 24 hours a day, means that even these low power usage figures have a measurable impact on UK emissions. Very approximately, cordless phones in the home add about half a million tonnes a year to UK emissions, or about 0.1% of the national total.

A saving of half of this would be useful. I was also interested in knowing whether the techniques used by BT to gain the claimed 50% saving could be transferred to other consumer electronics. Before making its claims about a 50% energy saving, I assumed that BT had done proper testing of existing phones and had carefully measured the energy consumption of new devices.

I was wrong. Here is the full text of an email interchange between a PR person at BT and me:

Dear XXXX

Thank you for this. (this refers to the BT newsletter announcing the new phones). Would it be possible to find out the expected electricity consumption, in use and on standby of the new range of DECT phones compared to the models you used as the base case? Apologies for the slightly nerdy question, but I am very interested to see how much electricity consumption you have been able to drive out of the devices.

Many thanks for any help

Chris Goodall

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Hi Chris

I have been in contact with my colleague and have been informed that the information you require is not available at the moment. The information is currently being worked out and as soon as it becomes available we will be able to update you.

I am sorry we are unable to assist on this occasion but please do not hesitate to contact us for any other enquiry.

Regards XXXX

So BT made very precise statements to the press and to industry analysts that were simply not backed up by the facts. It made extravagant claims about efficiency gains before it had bothered to do the research to check its assertions.

If BT had made similar statements about financial matters, it would have had a legal obligation to ensure basic truthfulness. It doesn’t appear to believe it should extend this rule to boasts about its performance as a good corporate citizen.

BT’s behaviour has something of a disappointing pattern. I made similar inquiries in October last year, asking about BT’s announced plans to install wind turbines at some of its exchanges. In particular, I asked whether the company had checked to ensure that transmission capacity would be available from the local electricity distribution company. Since the sites were in remote areas with weak transmission infrastructure, this is a key question to ask. Eventually, after several rounds of correspondence, it appeared that no investigation of this issue had actually taken place.

BT uses a large amount of the UK’s electricity. Quite reasonably, it is therefore trying to position itself as a leader on climate change issues. But it is acting irresponsibly in making green claims that are not backed up by reasonable evidence.

In the past three months, John Hutton, the UK government minister in charge of industry, has publicly backed an expansion of both nuclear and of offshore wind. Is this good for the UK’s climate targets? Possibly not.

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One issue never gets mentioned. Both wind and nuclear need to operate as many hours as they can. For offshore wind to make sense, operators need to be able to sell the power whenever the wind blows. Similarly, nuclear plants need to be ‘baseload’ and kept running day and night. Other plants, such as gas turbine generators can be turned on and off easily. The majority of their costs are fuel and it doesn’t matter very much if they work for ten hours a day, or twenty. They are a good complement to wind, whereas nuclear is in direct competition.

So Hutton’s support both for 32 gigawatts of wind and for a substantial increase in nuclear generation over and above today’s level is inconsistent. In early mornings, total UK demand for electricity falls to well below 30 gigawatts. Here is the pattern over the last eight days:

During much of this time (early March 2008), winds have been blowing reasonably strongly over the whole of the UK. I believe that offshore wind farms with a rated capacity of 32 gigawatts would have been producing outputs of 20-25 gigawatts much of the time. UK nuclear plants have a total generating capacity of about 10 gigawatts today, although some are out of service for maintenance. So if we simply replaced the ageing existing nuclear stations, we would have too much power for the early mornings without considering any other generating plants. And John Hutton says he wants much more than this.The implication of this is simply not understood. If we encourage large amounts of new nuclear capacity, we are likely to reduce the attraction of offshore wind to the point where it simply doesn’t get built.

A large part of the problem is that the UK is effectively isolated from the Continent’s power grid. In a rational world, we would be exporting the electricity from our vast resources of wind to central Europe. It’s true we do have an interconnection to France and a trickle feed to Ireland, but the capacity of these links is negligible. If we are to get substantial amounts of offshore wind, we need a substantial new power cable around the coast that can collect offshore wind and then take it to where it is needed, in the UK or elsewhere.

Elsewhere in the world, power grids are being reinforced to enable long-distance shipment of energy. This is a vital part of the infrastructure for a world that will use larger and larger amounts of renewable energy. Renewables are often unreliable and almost always intermittent. So we need more connections and more transmission lines to guarantee that when the sun stops shining in Spain, the wind from Denmark provides the power in Madrid. And when neither source is available, we can take electricity from Norwegian hydro plants which can be turned on and off at five seconds’ notice.

But nothing in this government’s plans envisages any substantial upgrading of the UK grid, chunky connections to Europe or the establishment of any large Norwegian-style storage reservoirs for hydro capacity.

Last month the Crown Estate published a fabulously detailed and much admired report on the cost of bringing an offshore cable from the wind farms of Shetland and mainland Scotland to London and on to Europe. The cost is substantial, about £1.7bn, (or about the price of half a nuclear generating plant). Although the UK’s liberalised electricity market provides incentives to build power stations, including nuclear, no one in the industry can see who could possibly build the east-coast offshore transmission line profitably. There is no similar incentive in place to build transmission infrastructure even though the long-term benefits to electricity consumers (and to our climate change problems) would be huge.

This is a huge and palpable flaw in the UK’s electricity market structure. Everybody knows about it, everybody sees it as a problem but nobody can do anything about it without government intervention. But the mantra from John Hutton remains the same: the market will decide.

I think it is true to say that nowhere else in the world does the government assume that a rational portfolio of low-carbon electricity generating stations will evolve without intervention on transmission infrastructure. In this country, the core failing is not the much maligned Renewables Obligation but the inability of the heavily regulated transmission system operator (National Grid) to make substantial investments in upgrading power links and hydro-storage facilities without breaching its obligations to Ofgem. Let me put this as clearly as I can: National Grid would not get permission to build the east-coast link from Ofgem. Without this permission, it can have no guarantee of covering its costs. National Grid is a statutory monopolist, although privately owned. No one else can build large-scale transmission infrastructure in England and Wales. So the offshore power grid won’t get built.

Unless we change this, pushing nuclear means we simply won’t get much more offshore (or onshore) wind. What’s possibly as important, we are also increasing the UK’s vulnerability to power shortages in the second half of the next decade. There are many things we need to alter if we are to get real growth in renewable generation, but the crucial task is to invest heavily in transmission infrastructure now.