27 Nov 2014

On Sea Level Rise

On Tuesday night this week, I had the pleasure of listening to Prof David Vaughn talking about the work of the British Antarctic Survey where he has worked almost all his adult life. Vaughn is Professor Ice Sheet and he spends his time exploring the goings on in Antarctica, Greenland and the 200,000 plus glaciers that pepper the world's mountain ranges. It's a fascinating area of science and one that's obviously key to our understanding of where our climate and our sea levels are heading.

At this point, I would expect a number of people to rise angrily from their perches and accuse me of listening to a pinko greenie engaged in a conspiracy to pull the wool over our eyes by manipulating the data to suggest we are all doomed. "British Antarctic Survey? British Alarmist Society, more like." I have no doubt that UKIP will be planning to slash their £44m annual budget under their charming "Axe all green subsidies" policy.

May I suggest that, before they do, they spend an hour listening to David Vaughn talk. He dresses very conservatively, he talks very quietly, he is polite almost to a fault. In fact, he comes on like an accountant, which perhaps is what he is actually is, albeit one with some very sophisticated measuring kit. He just weighs ice and measures sea levels. He looks for trends and patterns and he peers into the future to try and work out where things are headed, but he steers clear of making suggestions about what we should or shouldn't be doing — "that's for economists and politicians to decide".

What was interesting to me is the huge strides that have been made in our knowledge in the past few years, between the IPCC reports AR4 in 2007 and AR5 in 2013. We now have two satellites (the Grace mission) which are measuring gravitational variations caused by changes in mass at surface level. If the mass of an ice cap is changing, Grace will pick it up. Clever stuff.

And the mass of ice sheets is changing. As you might expect, it's decreasing, although the picture isn't  uniform nor necessarily easy to interpret. Thus far, the changes are fairly moderate and are occurring at the margins, but what scientists fear is that there might be a sudden catastrophic event. One area on the Antarctic coast is of particular concern because there the ice sheet rests on bedrock which is far below sea level and there is a possibility that relatively small changes in sea temperature could cause it to all slide into the sea. How big an area? The size of Cornwall? Belgium? Norway? No one knows, but Vaughn probably has a better handle on it than anybody else. If we can afford MI5 and MI6, then I think we can afford the BAS.

Back at the height of the last ice age when ice sheets covered much of the northern hemisphere, the global sea level was 120m lower than it is today. The Mediterranean was not there and there was a land bridge between Britain and France. The temperature was approximately 7°C colder than it is today.

Still locked up in the Greenland Ice sheet is another potential 7m of sea level rise and in Antarctica it's 60m, so if we were to head for a 4°C increase in global temperatures, which is within the bounds of possibility (though far from certain), then we could anticipate a much higher sea level, though it might take 500 years to play out.

What is known today is that global sea level is currently rising at 3.2mm per annum. It the last century, it averaged around 2mm and in the 19th century, they think it was around 0.8mm. There is no hiatus in sea level change — the rise is pretty much constant. 3.2mm may not sound like much, but that still equates to 300mm by 2100. In fact best estimates are rather more than this at present but it's a field open to a lot of doubt and speculation. (Sea level is affected by a number of factors beside ice sheet melt.) It's probable that the relatively small amount of climate warming that we've already seen has locked in sea levels rises of several meters, but the timescale on which it will all happen is contentious.

The questions are can we manage this? Can we arrest it? And over what timescales are we talking? Should we be planning now to mitigate sea level rises which won't be fully played out till maybe the 25th century? What exactly are our planning horizons? This isn't the stuff of blind panic: it's good old risk assessment played out over a very long timescale. It does however ask some very uncomfortable questions about whether our actions now are making things better or worse for our distant descendants and what exactly we are hoping to achieve on Planet Earth.

In the shorter term, what is likely to happen is that storm surge events like the one that accompanied Hurricane Sandy are going to get worse and more frequent, but we already know that our coastal cities (New Orleans) and infrastructure (Fukushima) are at much greater peril than we care to think about. Sea level rise simply changes the odds and, if you like, makes coastal protection more expensive. Right-wing commentators who claim that it's simply too expensive to stop burning fossil fuels should bear this in mind. The longer we keep bingeing, the bigger the hangover.

21 Nov 2014

Lighting the future

I visited LuxLive on Wednesday to see where the lighting industry is headed. As you might expect, it can be summed up in 3 letters — LED. They were everywhere and there was very little of anything else. For someone used to writing about construction, where the pace of change is lugubrious, it's quite exciting to see an industry undergoing a rapid transformation. For most players in this space, it is a question of how to add value to a product which is both dropping in price and increasing in quality all the time. It's not enough to just sell LEDs: the future market is just too unpredictable.

And many so-called experts turned out to be almost as clueless as me. I was told on good authority that dope growers have no use for LEDs because they can't do ultra-violet light. A quick Google afterwards revealed dozens of really cheap UV LEDs. In fact, we may be about to be entering a world where growing all manner of plants at home becomes a whole lot easier and more productive.

For the past ten years or so, much of the emphasis in the lighting industry has been on increasing energy efficiency both by squeezing more performance out of the lamps themselves and by adding better control gear and better design. The arrival of cheap and very efficient LEDs has already made much of this work look pointless. Cree, the NASDAQ-quoted LED powerhouse, have now produced an LED that delivers 300 lumens per watt, which is about eight times more efficient than the best compact fluorescent, and although it's not yet in commercial production, it seems just a matter of time before the bar is raised again. In five years time, maybe 1,000 lumens per watt will be possible. By then lighting will have become so cheap to run, that it will be nearly-free. An old-fashioned 60-watt bulb could be replaced by an LED running on less than half a watt. A whole house could be lit by as little as 10 watts at a cost of maybe £5 per annum.

Not that LEDs are without their issues. The light itself is produced from a very focussed source which means there is a glare issue. Lots of work is going into shielding and diffusing this glare and making it more acceptable in every application. Backwards compatibility with existing light circuits is not always guaranteed and there are issues with dimmers not working with LEDs though, again, technology seems now to be producing LEDs that will work with existing dimmers.

One of the neatest and simplest ideas I saw was at the Megaman stand where they had adapted a dimmer so that the colour appearance of the lamp got warmer as the light level was decreased. I'm not sure this is commercially available yet, but it seemed like a very simple way of addressing the issue of the colour appearance of the lamps which exercises some people quite a lot.

The future of cabled switching also seems to be in question. Lots of stands had wireless switch plates for lighting and Megaman were also displaying a wireless home automation system which allowed you to control the heating system as well, all from your smartphone. If this is really advantageous remains to be seen — I think most people will still want a physical switch or thermostat as well, if only because smartphones get misplaced or run out of battery or break down. Wireless switching really comes into its own when you want to pre-program your lighting or heating or switch it remotely, but how many people actually want that function? We will see.

In the meantime, the wireless switchers are not being helped by a protocol turf war rumbling away in the background. Wi-fi v Bluetooth v ZigBee v Z-wave. It's all very well have Z-wave enabled kit, but how do you know the world won't have gone fully wi-fi by 2025? You could end up being Betamaxed, although, to be fair, you won't exactly run short of content, so it may not be quite so critical as all the existing protocols will be supported for decades, even if they stop being used for new applications. Nevertheless, it doesn't help matters that it isn't clear which home wireless system will prevail.

14 Nov 2014

Eco Bollocks Award No 9: Clear Heater Units

Recently, I've become aware of some striking claims being made for electric radiant heating. Like a new way of heating homes has been discovered that is way more efficient than anything else that we have come across before. I think not.

The practice of using radiant heating is not new and it seems to work very well in many places. But claims that is somehow magically more efficient than other forms of heating  is, in my opinion, pure baloney.

Take a look at this website. Clear Heater Systems have a neat looking wall panel radiator which they claim will save you a pot of money. They claim that you can save up to 65% against gas heating on a three-bed semi, and up to 90% on electric heating on the same house. Impressed? Let's investigate.

Their claims are apparently backed-up by a piece of academic research by a chap from Leeds University which, at first glance, looks very compelling. It concludes: Overall, the results that we have produced show the Logicor Clear Heating System in a good light. They certainly do. 

However, if you read the report carefully, you can see that it's not quite all that it appears to be in its conclusion. The report is based on an analysis of the energy used in 53 properties in the north of England which have been fitted with the Clear Heater units. The results are, however, not being compared with properties heated by other methods, but with an estimated heat loss for each of these 53 properties, based on their own calculations using standard U-values. What this tells you is not how efficient Clear Heater units are but how inaccurate U-value calculations can be if used inappropriately. They are a useful tool for working out maximum heat loads, but not for predicting annual heating bills.

The methodology is even made explicit within the report. Buried away on page 4, under the heading Statistical Analysis, the author states that the study is not a measure of savings against competing heating systems but rather a measure of performance against theoretical heat losses. With the emphasis on the word theoretical

You'd have to be a bit of a Sherlock Holmes to figure out that the apples here are not being compared with other apples, but with a load of dodgy oranges. And it's on this basis that they claim that you can save pots of money against gas heating. Which is frankly incredible because the Clear Heater Units are electric radiators, albeit with a very thin carbon ceramic heating element sandwiched between two sheets of toughened glass. Much as they would have liked to, Logicor haven't managed to change the laws of physics and, for just hinting that they might have, they get a House 2.0 Eco Bollcocks award.