Sudden changes in electricity demand can cause problems for national power grids. Electricity has to be generated as it’s needed. If it isn’t planned for correctly, a sudden change in demand could in theory cause the national grid to “crash”, and lead to a blackout. Energy companies use complex models to forecast demand, and will also take into account occasions such as big sporting events, where television viewers will all put the kettle on at half time. So no doubt they are prepared for a drop in demand today. I suspect a trough is as much of a problem as a peak: how to deal with it? It might be necessary to take certain power stations offline, and restarting them can’t be that efficient. I’d be interested to know how much electricity, if any, Earth Hour actually saves when this is taken into account.

What would be far better for the Earth would be if people would think about switching lights off every day. I often despair at the number of lights left on at my workplace: in meeting rooms, kitchenettes, toilets, etc. despite those rooms not being in use. Every day I switch off several sets of lights as I walk past, often several times. I also can’t help but notice my neighbours, who seem to leave all the lights in their home on all the time, not just those in the room they are using.

So my suggestion would be to forget Earth Hour. If you want to register your views, take the time to write to elected representatives about it. Then make sure you always switch off lights in any rooms that are not in use – that will help not only the Earth, but also the electricity distributors!

The announcement that a new bridge is to be built across the Forth Estuary barely received a mention in the London-based UK press. I only managed to find an article in the Guardian. There was also an article tucked away on BBC News. This is quite disgraceful, considering that it will be one of the biggest civil engineering projects in the country.

The existing Forth Road Bridge, which opened in 1964, is still an engineering marvel, sweeping across the estuary in a single, graceful span. At the time it was built, it was the fourth longest in the world and the longest outside the USA, also making it the first bridge in Europe to have a span longer than a kilometre. Together with the nineteenth century rail bridge, it forms part of a world-famous view that no visitor to that part of Scotland should leave without seeing.

Unfortunately, traffic on the road bridge has outgrown all estimates. Corrosion has also been found inside the main suspension cables, which has caused a few of the thousands of wires that make up the cables to break. Worst-scenario estimates are that the bridge may have to close to lorries in 2013, and close completely in 2020. Hence the apparent need for a new bridge.

So far, amid all the reports (in Scottish newspapers) of the proposed new bridge, there has been little mention of the fate of the current bridge. Suggestions that it could be demolished are quite alarming. The 40-year-old bridge is already an important part of our heritage, and indeed this is recognised by the Category A listed status it was awarded in 2001. Fortunately, The Scotsman suggests that “experts believe it will ultimately be repaired to help cut cross-Forth congestion, which is predicted to continue to grow.” Let’s hope that will be the case, but at the the same time we should not be complacent. A campaign is needed to secure the bridge’s future.

Environmentalists are furious that a new bridge is to be built, as it will lead to increased traffic. They say the existing bridge should have been repaired instead. But they then go on to criticise the Scottish Government for “failure to guarantee the existing road bridge would be demolished once its ‘replacement’ was built.” Demolishing the bridge hardly seems a “green” measure. It would take a huge amount of energy (not to mention money) to demolish the structure, yet most of it is still perfectly sound. Transferring traffic onto the new bridge will allow the old bridge to be closed, making comprehensive repairs cheaper, easier and less disruptive. When the repaired bridge reopens, it can be restricted to cars only, or if the environmentalists object to that, why not use the old bridge exclusively for trams or buses?

The new bridge will have space reserved for future public transport use. Yet this provision has already been criticised as insufficient. One civil engineer has claimed that only 2500 passengers could be carried an hour, leaving 35,000 more people to use their cars. By utilising the existing bridge for public transport, the capacity could be increased many times over.

The proposed new bridge has been labelled as “iconic”, yet the artist’s impression shows a fairly standard-looking cable-stayed bridge. Unfortunately, modern construction techniques, which have made it easier to site bridge piers in water, have caused bridges to become more ugly. One only has to look at the Severn Estuary, where the elegant Severn Bridge of the ’60s has been joined by a modern, functional bridge that is largely just a concrete motorway viaduct, snaking its way across the mud.

The third Forth bridge is unlikely ever to match its predecessors in terms of achieving “iconic” status. Let’s ensure that this symbol of 21st century progress will always have those icons of the 19th and 20th centuries standing alongside it. The campaign to save the Forth Road Bridge should start now.

• Forth Bridges: coverage from The Scotsman
• Edinburgh photo gallery including the Forth Bridges from North Queensferry

It is an unglamorous town in the south of England known for its rail junction, power station and nuclear research laboratory but today, Didcot in Oxfordshire enjoys a new and enviable reputation – as the place whose residents enjoy the longest, healthiest lives in England and Wales.

Read the whole story in the Daily Telegraph.

One thing they don’t mention in the list of things that are “wrong” with Didcot is that the Ladygrove estate, officially the healthiest place in the country to live, is crossed by high voltage power lines. Have Powerwatch, and any other groups that campaign against supposed health risks of power lines, seen today’s article?

With such a complex issue, it’s difficult to say exactly why people might object to a new policy. In the case of “pay as you drive” road tolls, I have seen postings urging people to sign the petition against “tracking”. In fact, the exact wording of the petition is, “We the undersigned petition the Prime Minister to Scrap the planned vehicle tracking and road pricing policy.” This is a reference to the fact that Global Positioning System (GPS) technology is likely to be used to pinpoint the location of a vehicle, so that the correct tariff for driving in the area at a particular time can be levied. Now of course, GPS itself does not track anyone. The satellites broadcast signals that can be used by a GPS receiver to pinpoint its location. No information is sent back to the satellites. It is not yet clear how the road pricing system would operate, but it is possible to think of arrangements where journey data would not need to be sent back to a central location. Anyone truly concerned about tracking should try to distance themselves from those who simply don’t want to pay to drive, as the latter group could overshadow an important civil liberties issue.

The stated aim of road pricing is to reduce congestion. At first, a sensible alternative to installing expensive GPS equipment in every vehicle would seem to be simply to increase fuel duty, while at the same time eliminating the tax disc, and providing annual “MOT” roadworthiness checks for free. That would encourage people to drive less, even if they already owned a car, as the cost of keeping a car unused would be reduced. However, while fuel duty means that both high usage and inefficient vehicles are taxed more heavily, it does not allow prices to be varied according to the time of day. If congestion is the issue, drivers need to be deterred at particular times of day: during the morning and evening “rush hours”.

So, would road pricing have much of an effect on congestion during the rush hour? I don’t believe it would. There is already a big incentive not to travel during the rush hour: namely, congestion! Who in their right mind would choose to sit in queues of traffic for nearly an hour, when they have the choice of cruising along in 15 minutes? On the trains, peak-rate fares already exist, yet the rush hour commuter trains are as packed as ever. People travel at certain times because they have to. If congestion at particular times of day is to be eliminated, we all need to rethink our daily routines. People drive to work; they take their children to school. Both work and school start at around 9am. Reducing congestion during peak times will require more flexible working arrangements – something that could be encouraged by the government.

The other reason that people won’t abandon their cars even if new taxes are introduced is that the alternative – public transport – is extremely poor. Londoners complain about their transport system, yet visitors to the city from other parts of the UK marvel at the regular, integrated bus and underground system. Anywhere else, you are likely to discover that the route is served by three buses a day, and that those are operated by three different companies who print separate timetables, and whose tickets are not valid on each other’s services.

There’s no doubt that something needs to be done to stop our roads becoming even more congested, and we haven’t even begun to consider the effect of cars on the environment. Road pricing may well have a role to play in the end. However, there are many steps that need to be taken before the public will ever begin to accept the idea. First, reassurances must be given that the system will not mean a record of everyone’s journeys are collected and stored by a central agency. Then, people must be given the opportunity to make their journeys in a way that avoids the high peak-time charges: by providing a world-class public transport system, and by initiating a change in society where the “9 to 5″ culture disappears wherever possible. Without these measures, road charging will inevitably be seen by the petition-wielding public as nothing more than an attempt to impose yet another tax – and to keep tabs on what they are doing.

As it happened, Tony Blair was in the area that day to visit the Diamond synchrotron. On Greenpeace’s website it said he was in the area “coincidentally”. But you do have to wonder if they had inside information.

Greenpeace claim that Didcot power station is the second most polluting in the UK, and that two thirds of the energy is wasted as heat from the cooling towers. Their idea of localised generation where homes can be heated using the excess two thirds is reasonable, but this wasn’t really emphasised in any of the reports in the media – the nature of the protest overshadowed the most important part of their message. And as the Prime Minister said on the special local news programme that evening, he couldn’t just shut down the coal-firied power stations overnight, and any savings in CO₂ emissions would soon be wiped out by growth in the developing world. Those countries need to be brought on board if we are to fight climate change, and they aren’t going to stop building polluting power stations just because we’ve closed ours.

The following day, the power station’s owners, npower, were granted a High Court injunction, ordering Greenpeace to leave. The protesters were swiftly arrested on suspicion of aggravated trespass and criminal damage, although thanks to health and safety rules, it seems unlikely their punishment will be to clean up their graffiti.

• Greenpeace’s photos from the top of the chimney: 1 2
• Tony Blair responding to Greenpeace on Central News

Now, I think charging according to the amount thrown away is a good idea in principle. I’m often amazed at how much waste some small one- or two-people households produce each week, filling a large wheelie bin, whereas mine is often hardly half full. The relatively small number of people who bother to use the recycling service is also quite pitiful.

Unfortunately, I think the idea is unworkable, and likely to be extremely unfair. What is to stop people sneaking rubbish into a neighbour’s bin? Most people leave their dustbin out in the street the night before collection day; even if they don’t, it will be left outside all day while they are at work. The only solution to this would be to provide some new sort of high-tech bin complete with a lock, but as councils have already started to fit bins with microchips, it seems unlikely there are any plans to do this.

As with any sort of metering (water being another example) it’s likely to hit certain groups of people harder than others. People with young children, for example, might find they are paying much more for their refuse collection, which isn’t necessarily desirable (although perhaps this could be addressed through the benefit system). It could also be bad for people living in multiple-occupancy accommodation: the tidy, conservation-aware people who already have to pay high water or heating bills, and spend their time cleaning up after other people, might find they also have to pay for others’ rubbish to be thrown away. People living in flats might have a problem too, particularly if there are communal dustbins. Flat-dwellers also won’t have the chance to compost waste if they have no garden, and are already often denied the chance to recycle as it’s inconvenient for councils to include flats in their recycling schemes.

Another undesirable side-effect of charging by weight of a dustbin would be an increase in fly-tipping. At present, a lot of illegally dumped rubbish is commercial; in the future, we could see far more domestic waste in the hedgerows – or even simply left on the street corner with no-one wanting to claim responsibility for it, and even the most community-spirited neighbour reluctant to put it in their own bin due to the charge this would incur.

Finally, does anyone believe that the new fees for refuse collection would be balanced by a reduction in council tax?

So let’s not introduce this unfair and badly thought out scheme. Instead, they could start by offering incentives for people to recycle (for Leicester City Council, that could mean actually bothering to collect recyclable items that council tax payers have left in their green box outside their house…) Something also has to be done to reduce the amount of packaging that new items come in, and to educate people about re-using boxes, bags and envelopes.

And if they really want to encourage people to put less in their wheelie bins, could I suggest issuing smaller bins? If the size is insufficient, a larger bin could be provided, but at a cost. That would be far simpler to implement and harder to abuse. While not perfect as an idea, it would be less rubbish.

It has long been my view that bottled water is a con, or an expensive fashion accessory at best. Tap water in the UK is always perfectly safe to drink. It has to be, that’s the law. People pay their water bills, then that’s it, an endless supply of drinking water on tap. The Consumer Council says tap water costs about 0.1 pence per litre, compared to £1 for bottled water. So tap water is 1000 times more expensive.

So why do so many people insist on only drinking water bought in plastic bottles? Some people think that tap water is harmfull, which means they are simply misinformed. Others claim not to like the taste. That’s a matter of preference (I prefer taste of tap water) but there many methods of filtering water if they really insist on it. Then I suspect the issue becomes one of convenience – filtering water actually requires some effort. The hard water, which many people claim to like, possibly helps to prevent heart disease.

One unfortunate consequence is the effect on foreign visitors. In their home countries, tap water may well not be safe to drink, so bottled water is a necessity. However, this bottled water is usually much more reasonably priced than in the UK. These visitors arrive in the UK, see so many of the natives buying their bottles, so feel they have to do the same. They might even ask, “Is tap water safe?” To which they are often misinformed, “No it isn’t.” The UK already has a reputation as an expensive country, so having people pay a premium for water will ultimately not be good for the tourist industry.

Some brands of bottled water carry with them a certain image, a lifestyle of which people want to be a part. As usual, those foolish enough to follow fashion burn a hole in their pockets, although it has to be said that even the most exclusive designer clothes don’t normally cost 1000 times more than the unbranded equivalent. All I can suggest is, buy one bottle, then re-fill it from the tap. One of the leading brands actually prints on the label, “This bottle is intended for the exclusive use of (brandname) natural mineral water.” In other words, don’t re-fill it. It wouldn’t surprise me if in America it’s a criminal offence to do so under some draconian trademark law. Anyway, I’ll leave you to look out for which brand it is!

Buying water in a bottle is also bad for the environment. Think of all the energy that goes into making the bottles, into the bottling plant, into transporting the water to the shop, into transporting the bottle home from the shop.

Bottled water isn’t better for you. In fact, sometimes it can be harmful. In 2004, Coca-Cola attempted to launch their Dasani branded water in the UK. It soon emerged that they were taking tap water, filtering it, then adding some chemicals to improve the taste. This resulted in ridicule in the press, particularly as it resembled a scheme thought up by crafty east London market trader Del Trotter in the TV series Only Fools and Horses. Shortly after the launch, the authorities discovered that one of the additives was potentially carcinogenic. The Dasani brand was subsequently withdrawn from sale in Europe.

So the message is simply, when in the UK, do drink the water! The tap water, that is. Ignore people who say it isn’t safe, try filtering it if you don’t like the taste. But please don’t waste money by buying all your drinking water in bottles.

In an ideal world, we would be able to use renewable energy sources to meet all of our needs. Unfortunately, the technology does not yet exist for renewables to account for the bulk of our electricity supply. The current nuclear power stations are reaching the end of their lives and we need something to replace them. A decision on nuclear needs to be taken now so that the new plants can come online to take over from the old ones.

By the time the next generation of nuclear power stations are being decommissioned, we will hopefully have developed renewables sufficiently to replace them. We may well also have new alternative sources such as fusion power. None of this is ready yet, so we need just one more cycle of nuclear power in the meantime. But going for nuclear now must not mean research into renewables is cut back. Preferably, much more money should be made available as a matter of urgency.

One alternative to plug the gap would be to use gas-fired power stations, which are cleaner than traditional coal-fired ones. Unfortunately, Britain’s own gas supplies are running out so that we are increasingly reliant on imports from abroad, most notably from Russia. Domestic gas prices are already rocketing, but of even more concern in the future would be security of supply.

Part of me is always surprised when “environmentalists” oppose nuclear power. The largest threat to the environment is global warming, and in this respect nuclear is particularly “clean”. Some of them have condemned it as 50-year-old technology – if they’re going to look at it that way, how old is the technology of burning gas? And for how long have there been windmills? Among the general public, the biggest problem is fear. The only time they hear about nuclear power is when there is an accident. They’ve all heard of Windscale/Sellafield, but they probably don’t realise just how many nuclear plants there are in the country – most of them they will never have heard of because they have all ended their working lives without incident.

That leaves the issue of nuclear waste. The fact is, we already have some of this to deal with, it isn’t going to go away. Maybe if we hadn’t had any nuclear power before it would be a different situation. As it is, a new generation of stations would only double the amount of waste at the very most (and newer stations are supposed to produce less) – it isn’t as if we are going to see a ten-fold increase. They say it will be a legacy that lasts for millennia; but within a century, I’m sure the technology will exist to render nuclear waste safe one way or another.

In the last few years, terrorism has been a big issue, and some people are worried that nuclear power stations could be targets. Many years ago, I can remember seeing a film of an aircraft being flown into a mock-up of a reactor’s concrete shielding. The aircraft was literally vaporised. While of course security should be tight around power stations, the most dangerous form of nuclear terrorism would be a “dirty bomb” exploded in the centre of one of our cities. And there are many countries in the world where it would be much easier for terrorists to obtain radioactive material than in the UK. Ultimately, I don’t believe we should ever be influenced by the prospect of terrorism, otherwise the terrorists have already won.

Opponents of nuclear power complain that Blair is listening to the “nuclear lobby” (and equally, those in the nuclear industry moan that he listens to the “wind power lobby” and suchlike). I have no affiliation with any industry, but in common with most physicists, I believe that we need to continue to utilise nuclear energy for the time being until the alternatives become more viable. I hope that as the lights of Tony Blair’s term as prime minister are about to be extinguished, his legacy will ensure the country’s remain lit for decades to come.