Kate's Comment

Thoughts on British ICT, energy & environment, cloud computing and security from Memset's MD

Dispelling the green myths

As more people “wake up” to climate change we are seeing a lot of effort put towards starting to reduce our collective green-house gas emissions. Unfortunately however, there seems to be a lack of quantitative data being applied to many of these efforts, and consequently the media, individuals and business are often focusing on the wrong issues rather than putting the efforts towards combating the main contributors to our carbon footprint.

In this article I shall try to point out some examples of “environmental activities” that do little more than salve our conscience, making us feel we are “doing something good”, thus diverting attention from the real problem areas, as well as some examples of what I feel are total “green myths”.

Myth: Switch it off / standby power

There has been widespread media coverage of a “turn it off” campaign. Certainly, not leaving electrical devices (be it a PC or a TV) on at all times is plain wasteful, but getting people to totally turn such devices off at the plug rather than just letting it go into standby mode is, frankly, a bit of a waste of time.

The problem is that the figures used by the media are at least ten years out of date. For example, a modern TV built within the last 6 years uses about 0.5Watts in standby mode. That means that a TV would have to be on standby for about a month to use the same energy as boiling a kettle (approx 0.3kWh, or about 0.13KG CO2)!

Also, we should not forget that all the energy we use ultimately ends up as heat, thus warming up the office or house a little. Therefore, if the building is being heated at that time of year the the energy is not wasted anyway. In fact, when you compare the net effect of leaving devices on standby (rather than unplugging them) with the total carbon footprint of a typical home (most of which comes from burning gas), the total contribution is only 0.3%. If you want to make a difference, turn the thermostat down and wear a jumper – don’t worry about standby power.

The same applies to PCs; a modern desktop computer (with screen) will use around 2 Watts when in hibernate mode. Getting people to shut down their machines totally at night inconveniences them and wastes their time the next morning when they have to boot up and get back to where they were. Promoting the use of hibernate rather than shutting down is much better since they are more likely to do it, or even better use the built-in power management facilities in the PC to automatically standby or hibernate after a period of inactivity.

Myth: Home working is not that green

Travel is one of the most environmentally damaging activities we do in day-to-day life. Even if driving a very fuel efficient car, a 20 kilometres journey (ie. a short round-trip commute) will produce around 2KG of carbon emissions. Obviously public transport is much better, but it still better to encourage staff to work from home some of the time where practical.

The myth here is that someone working at home uses more energy than in the office because they are heating the house. Even in fairly cool climates, modern, well insulated homes only lose a few degrees celsius during the day, and since most people tend to prefer working in a slightly cooler environment anyway the natural dip in daytime temperature is not an issue. As well as that, most people would have their heating set to come on to have warmed up the house by the time they got home regardless so the overall effect is negligible. Additionally, if you get a proportion of the workforce to work remotely you can have smaller offices, which means less lighting, heating etc. Encouraging home working is definitely good from a green perspective.

One alternative though is to encourage staff to use more efficient modes of transport for commuting of course!

Myth: IT is very harmful to the environment

The IT industry has recently been the subject of some negative media attention regarding its contribution to the greenhouse gas emissions (around 2% globally according to Gartner). In particular, there have been comparisons to the airline industry which contributes a similar amount. Such comparisons are simply not appropriate; yes, the IT industry may generate 2-3% of Europe’s carbon emissions, but it contributes around 10% of our total GDP!

Additionally, the IT sector as a whole has been making huge leaps forwards in recent years. A server bought in 2006, for example, used twice the power and did half the work of one bought today; a four fold improvement. That said, there is still a lot of work to do in improving the efficiency of data centres, but again we are taking the issues very seriously and are making huge leaps forwards in efficiency thanks to technologies such as virtualisation.

Finally, IT is a key enabler of energy efficiency in other sectors; everything from home working (above) to efficient logistics. One could even argue that the 2% contribution is more than repaid by the use of IT to reduce other industries carbon footprint. If you are interested in what the IT industry is doing to combat climate change then read Intellect’s (the UK’s high tech trade association) recent report High Tech: Low Carbon – The role of technology in tackling climate change.

As a slight aside it is also worth remembering that, in the case of a desktop PC at least, the embedded energy cost of manufacture and distribution (around 1,000 kWh, of half a tonne of CO2) is a large proportion of its lifetime energy cost. What this means is that it is worth trying to avoid replacing desktop PCs for as long as possible. Over a 5 year lifetime with typical office use, an average PC’s total energy cost would be roughly 50% in manufacture and 50% in electricity used. The situation is different for servers, however, and in some cases it makes both environmental and economic sense to replace them after 2-3 years.

Myth: Recycling paper is great

Many businesses make a big show of how good they are at recycling paper. In reality though, while it is certainly a good thing to do, it is not one of the big issues we should be worrying about; most of our paper comes from renewable sources in Norway, not from deforestation of rain forests, and in fact the energy needed to recycle paper is only marginally less than the energy needed to extract it from the tree in the first place. Additionally, because of shortening of fibres in the paper you can only recycle it about 3 times, and if you use cross-cut shredders then you cannot recycle the paper at all.

As well as the above, one could argue that growing trees, turning them into paper and then burying them in landfill sites is actually a rather good method of carbon sequestration, provided that you capture the any methane produced from the landfill by anaerobic degradation of organic waste.

There is a danger that focusing on things like paper recycling becomes a distraction, encouraging people to believe they are doing real good when what they should be worrying about are things like using less energy in the office, travelling less and improving the utilisation of IT existing resources. That said, recycling paper (and trying to avoid using it at all) is certainly something that we should do, we just need to retain perspective and realise that it is much less significant than many other environmental initiatives.

Myth: We can’t make a real difference, so there is no point trying

I am frequently faced with apathetic views on tackling climate change, the basic premise being that the developing world (especially China) is going to vastly outstrip Europe in terms of greenhouse gas emissions perhaps within a decade at its current rate of development.

Yes, in reality, even if the whole of Europe became super-green it would not be enough to reverse the global trend – we need to encourage the developing world to be more efficient as well. Therefore, what we should be doing in business is demonstrating to China and similar countries that it is possible to be green while still having a vibrant economy and not inconveniencing end-users. Europe’s collective role in combating climate change will not ultimately be down to our own reductions alone; it will be though us being exemplars to the rest of the world on how to be a successful low-carbon economy.

30 comments

  1. dougalder.pip.verisignlabs.com Apr 14, 2008 00:07 Good article Kate. I've been working from home since 2002 and it's great. We switched all the lights in the house to compact fluorescents and it has made a huge difference in our bill. Next step is to add more insulation to the house, and maybe I'll get adventuresome and add some solar panels. Your points about standby mode are spot on. I can just imagine the frustration joe average would have turning everything back on every morning, waiting for the cable/DSL modem to come back up , wireless/wired router too if he has one (which he should) etc etc etc. The hassle would prevent most from doing so and would put them off any other green activities.
  2. anonymous Jun 4, 2008 07:15 Your article on the BCS site (no comment facility there, so I came here) says "a modern desktop computer (with screen) will use around 2 watts when in hibernate mode."

    In hibernate mode a PC uses none. Here's a quote from Windows' Power Options Properties: "When your computer hibernates, it stores whatever it has in memory on hard disk and shuts down."

    I can hibernate my PC, and unplug it completely. When I start it up again, it restores to where I left off.

    I suspect you're referring to standby mode, unless you're referring to Linux or Mac 'PCs'.
    Roy
  3. anonymous Jun 4, 2008 09:14 Hibernation may be green and efficient, but there is a security issue. Many laptops now use full disk encryption to protect the data when they are not in use.

    This is effective only if the laptop is completely shut down. If a laptop is left in hibernation, it must be protected by other means to ensure that its data remains secure.

    Roger Smith
    Secretary, BCS-ISSG
  4. anonymous Jun 4, 2008 11:04 Thanks Kate for the interesting article.

    I have long thought that standby was likely to be more efficient than the figures quoted but could never find hard data. Do you have a reference?

    I thought you were about to say "home working is not that green" but read on to see you were exploding the myth. I was shocked to think that a short journey produces 2kg of CO2, wondering where does all that carbon come from?

    Interesting to think of burying paper as carbon sequestration - whatever next!

    Thanks again
  5. anonymous Jun 6, 2008 17:09 I began my employment working from home. I didn't enjoy it at all.

    I used to think this was connected to my disability, because it is difficult for me to get out and about the office is my main point of social contact however at a recent family gathering I was speaking to a relative who lives some distance away.

    She told me of her friends' husband who took up a home working post. He thought it would be an idyllic life but he soon became clinically depressed through sitting on his own all the time.

    Speaking to people who have retired from my office they always say that they miss the people but not the work. When you work from home, work is all you have.

    For me it was like being in solitary confinement.

    If home-working became the norm, you would reduce the UK's carbon footprint more than you think... the population would reduce due to an increase in suicides.

    Cheers, Dave Williams
  6. Kate Jun 9, 2008 16:36 Thank you. :)
  7. anonymous Jun 9, 2008 16:36 Good article :)
  8. Kate Jun 23, 2008 14:37 No, in both standby and hibernate modes the PC uses a very small amount of power - the PSU uses a tiny amount even when the machine is not drawing power from it. The 2Watts figure comes from Oxford Uni computing department's tests on their PCs by the way.
  9. Kate Jun 23, 2008 14:39 If the BIOS is properly written then the laptop will clear the encryption password from memory before hibernating and will ask for it to be re-entered on exiting hibernate. Admittedly, if the disk encryption is being done at the OS level then it does present a security risk.
  10. Kate Jun 23, 2008 14:41 I have to agree with you, Dave - when I started Memset I spent a lot of time working from home and it was very unpleasant. Additionally you don't get that "corridor osmosis" (or watercooler chat) that you have in an office - such informal communication is very important for improving efficiency and innovation I think.

    No, I would never advocate full-time home working, but I would advocate spending a day or so per week at home for certain jobs, and there are some people that work very well at home without suffering from isolation (as long as they spend some time in the office).
  11. Kate Jun 23, 2008 15:10 I got the figures about hibernate / standby from a talk by Oxford uni computing services, but have validated them myself with a clamp meter around the power cable. If you are interested in such things I'd encourage you to buy one and play with it - they are quite cheap and very enlightening!

    "Where does all that carbon come from"?

    I worked that out based on a typical emissions of 120 grams CO2/km (check any car manufacturer web site). As for where it all comes from, it is pretty clear when you think about what a car does. Petrol is mostly pure hydrocarbons, and a litre of petrol weighs about 0.7KG (water would be 1KG). An average car burns about 0.1 litre / mile, and hydrocarbons are mostly carbon by weight, so very crudely that gives us about 40 grams carbon / KM. Over a 20KM journey, that gives 0.8KG carbon, or if we measure it as CO2 (which most people do) we have to multiply by roughly 3 to account for the oxygen in the C02 giving us 2.6KG.

    Basically, next time you are filling your tank with petrol imagine that each litre you put in will be converted into roughly 1.5KG of CO2 and you will not be far wrong.
  12. anonymous Jul 21, 2008 20:25 I read your article in the latest BCS ITNOW issue and was most impressed. Thank you for trying to dispel many of the current myths about 'going green' or 'how we can stop global warming'. Your comment is well taken that we need to set a good example to the likes of China.

    I feel strongly that our government, and also perhaps the media, are trying to distract us and make us all guilty of confusing activity with progress. What I feel that we really need is a quantified list of what we as individuals and what we as a nation are spending in the way of energy or generating in the way of greenhouse gasses, including those used in the manufacture of goods and the provision of services. Only then can we channel our scarce resources effectively into cutting down our consumption in the worst areas, and thereby hope to make any noticeable impact.
    Do you have any idea if such a list already exists and, if so, where I can see it?

    Keep up the excellent work!
  13. anonymous Jul 23, 2008 15:47 Good article (I read it in ITNOW). Thanks.

    But I'm surprised that you found that hibernation takes any current - the machine's actually switched off! Maybe there's some residual current being taken by the power supply even when switched off - try it out.

    But there's a much deeper problem with hibernation - it doesn't always work. And there's nothing more depressing than pressing the hibernation button, going for lunch, and coming back an hour later to find "preparing to hibernate" still on the screen. Needless to say, Microsoft don't provide any tools for debugging this little problem.
  14. Kate Jul 23, 2008 18:06 Most of the PC may be off when hibernating, but the power supply unit is still powered on and is still doing a bit of conversion - hence why you still get things like the LED glowing even when hibernated on many PCs. That is only a tiny amount of power though, hence 1-2 Watts.

    I'm only 90% certain about the above by the way so someone please correct me if I'm wrong! I did get those figures from Oxford uni computing services (who did a review of their own PC's power consumption) so they should be correct.
  15. Kate Jul 23, 2008 18:10 Getting hold of that sort of "list" is something I've wondered about too, but have come to the conclusion that it is not missing due to some sort of conspiracy, but merely because our government (and media) don't really have a good grasp of the issues at hand.

    I agree that there is a great need for some quantification in the whole climate change / carbon debate, driven not be politicians and media but by university-based expert economists and climatologists. In the mean time I would encourage all of us to not take for granted what we hear as "sound environmental practice" and instead do some googling, get our your calculator and work out the numbers for yourself.
  16. anonymous Jul 24, 2008 08:19 Hi

    I've worked from home pretty well full time for nearly 8 years - and I'm definitely not suicidal! The trick is to make sure you build social time into your work life - which can be tricky if you're not naturally outgoing and rely on the office environment to bring people to you rather than going out to find them.

    Suggestions that worked for me included;

    make sure you have at least 1 client meeting or lunch with ex-colleague/business contact a week
    using instant messenger to keep in touch with people I work with regularly - just knowing they're logged in makes you feel less alone
    go out somewhere during working hours at least once a day, walk to the shop/post office, spend time in an internet cafe, just go somewhere there are other people
    set a limit to work time, so you have a clear deadline to stop work and move into free time. Some people find it helps to walk out the door and back in to 'start' work, you could do the opposite at the end of the day or at lunch time

    The website I run (www.skillfair.co.uk) has over 8000 consultants/freelancers etc most of whom work from home. Research we've done shows that they do this about 3 days a week on avergae - haven't totted up the carbon they're collectively saving but the effect must be huge - and they all seem pretty happy not to be slogging in and out of the office every day :-)

    Good article by the way - nice to know that standby isn't as black as its painted!

    Regards

    Gill Hunt
    Skillfair
  17. anonymous Jul 26, 2008 12:31 Agreed about the power. Presumably the PC takes exactly the same amount of power when switched off (but not at the mains). But 1-2 watts seems lot for a LED! I imagine that there are also the losses in the power supply.

    I can't agree with the argument that the heat is used to heat the room, though. OK in winter but in summer it merely raises the temperature of the room and makes it less bearable to work in. Unless of course you've got air conditioning...

    But my main thrust was that if hibernation can't be made to work reliably, what use is there in recommending it?
  18. anonymous Jul 27, 2008 12:47 I tried it out on my laptop and a friend's desktop with a cheapo power meter (£5.99 from Lidl as I remember), so the calibration might not be brilliant.

    The laptop showed no power (or, rather, less than 1 watt) on hibernation of power-off state. The desktop showed between 1 and 2 watts on both. Probably an inefficient power supply module, but I don't have the kit to investigate further.

    So it looks as if your figures are fairly accurate, at least on a statistical sample of 1.
  19. anonymous Oct 8, 2008 15:55 Interesting article, where does the data for the 50:50 embedded energy and energy in use for a pc over a 5 year life cycle come from?

    James
  20. Kate Oct 10, 2008 19:47 Hi James - are you the same James from the other posting btw? This is copy & pasted from my previous reply:

    Anyway, I got my embedded-carbon figures from a collection of sources; some direct from Fujitsu on their new super-green manufacture plant (at a conference on green IT at Oxford Uni), and some direct from Dell (who we buy most of our kit from). The most helpful source, though, was a paper in Environmental Science & Technology (2004, 38, 6166-6174) by Eric Williams titled "Energy Intensity of Computer Manufacturing: Hybrid Assessment Combining Process and Economic Input-Output Methods".

    I took that paper and applied some of the latest figures from the manufacturers to his calculations. I also did a bit of research on LCDs (his paper talks about CRTs), but there was not a lot of info on manufacturing costs so I it ended up being a bit of an educated guess.

    To answer your question, though, the 50:50 comes from my own calculations based the above-sourced embedded-carbon figures and normal usages. The actual range I got, by the way, was between 60:40 and 40:60, so I plumped for the middle. :)
  21. Kate Oct 10, 2008 19:49 In Britain we leave our heating on for as many as 9 months out of the year - depends where you live I guess!! :)

    As for hibernate, I have not come across a case of it not working in the last few years.... admittedly, I have not tried using Vista in a serious manner personally (I gave up Windows some time ago) and it would not surprise me if it failed to hibernate reliably ;)
  22. anonymous Oct 21, 2008 16:02 Kate, what were the figures that you believe are ten years out of date?

    Can you tell us how you came up with the 0.5W figure for TVs: is this from manufacturers' data or did you measure some samples yourself with your clamp meter?

    What make and model clamp meter are you using?

    Can you confirm that you're just putting it around the device's own mains flex without modifying the flex in any way?
  23. Kate Oct 27, 2008 15:08 I have read the media a few times quoting figures in the 5-10W region for standby power consumption, which a number of my contacts in the consumer electronics industry have confirmed that are about ten years out of date (ie. the situation has not been that for most responsible manufacturers since the late 90's).

    As for what a modern TV (or stereo) consumes on standby, I have looked at both the manufacturers' data and measured it myself, and it is indeed very small (only a few hundred mili-Watts). The main difference, I believe, is in improvements in switch-mode power supplies (the bit that converts 200+V AC into low-voltage DC) which used to be very inefficient and had a constant power draw of a few Watts even when the devices they were powering were using very little, for example just keeping the LED glowing.

    I did not use a clamp meter actually - I used one of the "plug in and measure" types, a Prodigit Electronics 2000MU, reviewed here. They are supposed to be pretty accurate! If you are getting some different figures I'd love to hear them though - I have only tried it on kit from big-name companies like Panasonic, Phillips & Sony.
  24. anonymous Nov 2, 2008 18:41 Kate, I think you're basically right. I asked because our 2-year old Samsung LCD uses 2W in standby, and I mostly see figures like 2-4W being bandied about on various web sites (for example, www.ee-tv.org/index.php/facts_and_figures/en and news.bbc.co.uk/1/hi/business/6076658.stm).

    A quick trawl of manufacturers' data for a random selection of current models gives a wide range of standby powers: 0.15W (for a Philips set), 0.19W (Sony), 0.7W (Toshiba), 1.2W (JVC) and 6W (Beko). Which demonstrates the differences between leading-edge makes, good makes and cheap makes. Since it takes a while for leading-edge technology to filter through to other manufacturers and to consumers, I suspect no one knows what the average actually is for the TVs currently in British homes. But I guess that 2-4W figure sounds plausible. Dunno really.

    One point I would make is that it's not just an LED that is powered in standby: it's also the circuits that detect "turn on" signals from the remote control or connected equipment. And in many TVs this is now configurable; it is one way that manufacturers are obtaining ultra-low consumptions, but it means that many consumers will not be operating their TVs at the lowest possible settings. e.g. My mate's new Sony has a 0.19W standby. But configure it so that a HDMI signal can turn it on and the standby consumption trebles. It also has a "quick start" mode which uses 16W for the first 2 hours in standby, giving an average during a day of over 2W.

    The one DVD recorder that I'm aware of uses either 2W or 15W depending on which standby option is selected. In general, I don't think it's TVs that are the worst offenders when standing by. The boxes underneath them use more (partly because they need to power circuits to loop through the RF and SCART signals). In our house, the boxes use 13W between them in standby. The main culprit is the Freeview receiver, at 7W. How representative that is, I have no idea. But I suspect people who unplug their TVs and leave their digital receivers on standby have been misinformed. I'd be interested to know whether you have any better figures than mine for the under-TV boxes.
  25. anonymous Nov 2, 2008 18:44 Were you plugging a lot of TVs into the same extension lead and taking an average? Otherwise, I can't see how you could measure a few hundred mW with a meter that only goes down to 1W. You weren't getting confused by the display on the 2000M were you? It shows 4W as "04" which I was mistaking for 0.4W when I first used it. Perhaps it's just me.

    Given that good test equipment costs £hundreds, I wouldn't expect a £10 meter to be very accurate at small wattages, especially with the non-sinusoidal loads presented by switched-mode power supplies. The meter has to detect a few milliamps and it has to determine the power factor from harmonics in the waveform, which is a lot to ask at the price.

    You mentioned putting "a clamp meter around the power cable" to measure the standby power consumption of PCs. I hope you're aware of the need to separate the live and neutral wires and put the clamp meter around just one of them. By clamping the whole flex, you'd be measuring the difference between the live and neutral, and getting a false reading close to 0.

    In any case, when calculating CO2 emissions, what matters is not the real power of the appliance but the apparent power (normally expressed in VA rather than W) "seen" by the electricity generators after power factor correction. This is not trivial to determine, but will be higher than the wattage shown by the meter. A full analysis would take into account transmission losses, and the fact that CO2 per VA varies throughout the day because of the different mixes of power plants that are brought on line. CO2 calculations can only really give ballpark figures. That doesn't stop web sites such as www.energysavingtrust.org.uk quoting figures with 3 or 4-digit precision!
  26. Kate Nov 3, 2008 14:31 Hmm, I definitely remember reading hundreds of milliwatts for my TV and Hi-Fi... I must have done them with my multimeter and one of those wiring blocks if the meter I mentioned does not go to fractions of a Watt. I shall have to check it.

    Anyway, you are quite wrong that equipment to measure millwatts is expensive!! Any standard multimeter will do it. The only trouble is that they don't usually have a handy way to do it safely (I would not recommend my method).

    Equally, transmission losses are only a few percent at most. We looked into that when determining our "real" data centre footprint, and worrying about variations during the day due to different sorts of power station being online is taking it to an extreme! Again, a quick sanity-check reveals that cannot be a significant factor in the grander scheme.
  27. anonymous Nov 5, 2008 19:09 Quite wrong? At least you didn't say I was very wrong! Seriously, if you're aware of an inexpensive multimeter that can measure milliwatts (not milliamps, remember) and can do so accurately even with non-sinusoidal loads like switched-mode power supplies, I'd really like to know about it.

    Basic multimeters cannot measure voltage and current at the same time, which means there is no way to determine the power factor, and so the real power cannot be calculated (wattage is volts times amps times power factor). There is at least one multimeter that has a plug-in attachment so that it can make these measurements. And safely. But it isn't cheap. And it's not much better than a power monitor or clamp meter. None of them have enough sensitivity for small wattages.

    And the worry with cheap meters is always how they determine an RMS value for the current. Many have simple average-responding circuits that only work with currents that follow a pure sine wave. Give them a waveform with harmonics and the readings will be incorrect.

    The figure we use for losses is 15.5%, which comes from industry data (1.5% high-voltage grid, 6% distribution and 8% production). If you have reason to believe this is wrong, it is important that it's publicised.

    Just as an example of what can go wrong if we're not careful, suppose a meter shows 2W for the standby power for some appliance. If the meter lacks sensitivity, or has not been calibrated for non-sinusoidal currents, the true wattage could be a lot higher. It might even fluctuate over time and our reading might not be representative. But let's call it 3W. If the site power factor (after attempted correction) is 0.6 (just to make the maths easy), then 3W puts a load on the supply of 5VA. Taking losses into account, that's equivalent to 6VA at the generators. If the appliance is left on standby for a year, the generators would average 24 kg of CO2. But if all appliances were no longer left on standby, the emissions would tend to be reduced at the highest rate (by burning less coal) and the saving for our example appliance could be as much as 47 kg of CO2. Not 8 kg, which is the figure we would get if we based the calculation solely on the 2W displayed on the meter.

    BTW I appreciate that AC power is a complex subject. If I've used any terminology that you're not familiar with, I'd be happy to explain it.
  28. Kate Nov 6, 2008 10:04 I was speaking to Peter Hopton from Very PC about this at the Green IT expo yesterday. You are right that the power factor and "simple" measurements of AC current can come up with very misleading results (which is why a clamp meter is no good), but my mutimeter does do milliWatts - I don't think it was a terribly expensive one though (£40 perhaps).

    Peter's estimation was that non-specialist kit (which costs around £400) might be 10-20% inaccurate when measuring low-wattage AC. Even then though, a measurement of 0.5W is still definitely below one Watt for the standby figure. The innacuracies are not an order of magnitude, and I don't believe this detracts from my fundamental point;

    My view is that technology should be the solution wherever possible, not changing behaviors and causing people minor inconvenience and irritation. Low standby power is one example, as is using the auto-hibernate option rather switching PCs off. Additionally, in our country where we need heating for a large part of the year, the wasted energy just warms the home and marginally reduces fuel bills.

    Also, the level of standby power in most modern equipment (which even with possible inefficiencies is still well below 1 Watt) makes it an inconsequential thing to worry about, and has the real danger of making people think they are doing some real good when they are not.

    Therefore, I believe we should encourage people to do things that have a real effect (using public transport, turning off lights etc) rather than fretting about the trivial.

    Obviously if you are a super-informed individual who cares about every bit of your carbon footprint then more power to your elbow! When trying to make changes in behavior of the less-well informed, though, we should focus on the big issues.
  29. Martin Sep 9, 2009 17:10 Sorry but some of your facts re paper recycling are incorrect. Unfortunately as with all statements regarding recycling and waste - the carbon cycle is very complicated. All I can say for now is - in the UK it is EXTREMELY important to recycle paper! The energy used to recycle paper is significantly smaller than that used to manufacture paper from woodpulp. For a start, the alternative is to have it landfilled or incinerated (at approximately 20% energy efficiency) Not a good alternative at all and basically a poor use of resources, especially as we have to import the majority of our paper.
  30. Kate Craig-Wood Sep 9, 2009 18:10 @Martin If my facts are wrong then please feel free to cite reference to the correct information. ;)

    The best thing to do with paper is to leave it on a shelf, or if you are not going to keep it then do not use it in the first place.

    If it goes into land fill then, provided that you don't let the anaerobic bugs at it (thus creating methane, which is Very Bad), again we have an excellent form of carbon sequestration. What we want to be doing is growing trees (made of CO2 and H2O), chopping them down, and then leaving them to sit there forever - underground or on my book shelf, does not matter really!

    Recycling paper is very energy intensive, and I remain convinced that it is not a large amount more to extract it from the trees in the first place, but I would be delighted if someone could prove to me otherwise. My belief is, I admit, based on anecdotal descriptions of the processes involved, but my sources include the CEO of a large recycled paper supplier.

    As for burning, if you use gasification then the efficiencies are much higher (well over 50%), and some serious green folks with money to invest are looking to build biomass-fired power plants. That biomass is mostly fast-growing trees. May as well be paper!

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