Q&A with the 10:10 campaign's Duncan Clark
Ever wondered which is greener - supporting developing world farmers, or eating local food with fewer "food miles"? What about brown and white sugar? From the big questions, to the slightly less big questions, carbon expert Duncan Clark from 10:10 was here to answer your questions in September 2010.
Q. Italianmummy:"Green" loo paper is supposed to need much more water to be produced compared to the ordinary kind, not to speak of the factory waste it leaves behind. Which way should we go?
A. Duncan: The only really important thing is to use recycled paper wherever possible – including with loo roll. On average, recycled paper takes around 50% less energy to produce than paper from virgin materials
Q. YunoYurburbson: Sugar. White sugar comes in paper packets. Brown sugar comes in plastic bags. Why? And which should I buy?
A. Duncan: I'm no expert on the workings of the sugar industry, but my guess would be that the answer to your first question is simply that plastic allows the shopper to see that it’s brown (and what type of brown), whereas white is the default and has always come in paper packets, so there's no compelling reason to switch.
As for which you should buy, the short answer is that it's not going to make much different each way. In terms of the packets, paper often has a higher carbon footprint than plastic, as it's much heavier, but then it's also recyclable, so the issues aren't clear cut there. In terms of the sugar, probably the greenest would be raw sugar, as it's less processed, which isn't true for normal brown sugar (which I believe is often white sugar with molasses added).
But this is a good example of something that you probably shouldn't spend too much time worrying about, as the implications for the planet will be so minute. Better to buy whatever sugar you like best and use your environmental energy thinking about something more significant.
Q. strandedatsea: What is your best answer to the supporting developing world farmers versus buying low air miles and home grown produce debate?
A. Duncan: The first thing I would say is that "food miles" aren't necessarily very significant for food transported by boat – and that includes the vast majority of imports from distant countries. Sure, the greenest option of all is to eat seasonal food produced close to home, but looked at in terms of emissions per kilo of food transported, shipping isn't a huge problem – even if the food is coming from the other side of the world. Hence many tropical foods such as bananas are very good value, carbon-wise.
Where things differ is when the food is flown. That normally means high-value perishables such as out-of-season mangetout and berries. Unfortunately, these are the ones that most commonly come from some of the countries most in need of foreign income, which explains why Oxfam and other groups are keen to avoid green-minded consumers boycotting air-freighted imports.
I can see both sides of the argument, but ultimately it's surely madness to fly food around the world unnecessarily. So my advice would be favour most exports from developing countries, especially Fairtrade ones, but try to minimise purchases of air-freighted foods
Q. Rob1n: It's generally accepted to be a good thing for people to grow their own food and I agree there are lots of benefits from this aside from the green issue, but is this really an efficient system? How efficient is it for lots of individuals to be putting all that energy into growing their own stuff and all requiring their own tools, spade, fork, rake, wheelbarrow etc...? How much of the produce ends up being wasted or unsuccessful because people don't know what they're doing? Wouldn't it be a better idea to encourage larger scale local food production & local consumption?
A. Duncan: That's a good question. Certainly if you bought loads of kit to grow two soggy tomatoes and then gave up, then you're not going to be cutting any carbon. That said, most people with a decent-sized garden have most of that kit already – and it is surprisingly easy to get a crop big enough to displace a decent amount of supermarket shopping.
However, I think the key point about growing your own is not that you displace food grown elsewhere, as is usually claimed. That said, community-based agriculture is great, too, and can be more practical, too, as you suggest. Local scheme of this type are popping up all over the place, which is encouraging.
Q. Rob1n: Leading on from this, I like to cook all my own food from scratch and enjoy baking but from an energy efficiency/carbon reduction point of view, is it better to buy a convenience meal that goes in the microwave for four minutes than potentially have the electric cooker/gas hob on for two hours or more?
A. Duncan: There's no simple answer to this – it's always case by case. Ready meals often have lots of embedded emissions, because they are often flash-refrigerated and then need to be kept cool for days or weeks (in the van, in the shop, in the home, etc). On the other hand, they often don't take much energy to cook at home, as you say.
Regarding the greenest way to cook, that actually depends partly on the time of year as well as the type of cooker. In the winter, when you might have the central heating on, having a gas hob going is 100% efficient – all the heat from the fuel goes into the food or into the kitchen. That's better than heating with a gas boiler that throws maybe 10% of the fuel energy out of the flue.
Also, it's worth noting that gas is greener than electricity, because you don't throw energy away in cooling towers and transmission lines.
Q. Takver: I wonder what your thoughts are on low carbon heating for the UK. We also have wood fired central heating, which is fine as we're in the countryside in wet Wales, but recently visiting friends in their flat London I was at a loss as to what the answer would be post gas/oil to heating the mass of dwellings in towns and cities.
A. Duncan: It's already possible to install wood-burning stoves that are sufficiently clean-burning to be exempt from city smokeless rules. However, these are only for heating rooms – not for powering a central heating boiler, which involves generating more smoke.
There are at least four other types of solution, all of which have their place:
- Heat pumps. These are like fridges in reverse –they use an electric compressor to generate useful heat from the ground or air. They work well if properly installed (which isn't always the case) but only in well insulated homes. Of course, to be truly renewable, they need to be combined with some form of renewable electricity to power the pump.
- District heating. Currently our electricity supply comes from giant power stations that have to throw away the huge amounts of heat produced as a byproduct. If you build smaller, clearer gas or wood power stations in urban areas, then the waste heat can be pumped to local homes. This is already popular in Scandinavia.
- Biogas. It's possible to turn organic waste or wood into biogas and push it through the normal gas grid. This doesn't happen much yet, though the government are exploring it.
Better buildings. If homes are built to passivhaus standard, they are so well insulated that they don't need a central heating system. The people and appliances in them create enough warm to keep the place at an idea temperature, topped up a little in particularly cold weather by an electric heater.
Q. PigletJohn: I have seen some very heated arguments about PhotoVoltaic electricity generation (expensive solar cells on the house roof) selling electricity to the grid. I understand that the people with these cells receive more money for their electricity than the wholesale electricity price on the open market, and that the money is paid by the electricity companies out of the money they charge their other customers. So the many poor people's electricity bills are higher, in order to pay money to the richer people with solar collectors.
A. Duncan: Yes, that's right. The feed-in tariffs allow people installing solar PV panels to get paid, and everyone else (rich and poor!) pays the bill. This is, on the one hand, completely unfair, as you say. On the other hand, it's in everyone's interest (in terms of climate change and energy security) that we quickly ramp up the amount of renewable energy on the grid.
Feed-in tariffs help with this by unlocking private funds that otherwise wouldn't be available and therefore would have to be funded by the tax-payer. The idea is that they also stimulate early adopters of panels, which boosts production, leading to lower panel prices for everyone in the long run.
It's also worth noting that if the person buying the panels had just left their money in a savings account, then they may well have ended up just as well off over the 25 years of the scheme. In other words, if the subsidy was any smaller, then it might not be a very effective way to stimulate take-up of solar.
Another criticism of the feed-in tariffs is that they are bad value for money, because a solar panel will generate less clean energy per pound spent than, say, a large wind turbine. This is absolutely true, though there are counterarguments – such as the fact that the people in the home tend to quickly slash their energy consumption, and their house becomes a visible advert for renewable energy.
Q. Rob1n: Carbon emissions might not be considered to be so much of a problem if there were fewer of us on the planet - should we feel guilty about having children or try to restrict the number of children we have?
A. Duncan: It depends on how you look at it. Inevitably having children creates future demand for energy. And yes, the more people there are on the planet the harder it may be to swiftly and equitably reduce global emissions. So having loads of children may not be the greenest thing to do. However, having a couple of kids isn't so much adding to the population over the long term; it's simply not actively seeking to reduce it, which I would argue is quite different. One other (slightly tenuous) point: if everyone concerned about the planet stopped reproducing, might that not create a kind of reverse Darwinian mechanism by which environmental awareness on behalf of the common good is gradually cut out of society?
Q. Bogwobbit: I'd like to ask what one thing, individuals could do (as a first step to being green so to speak) that would make the most difference, e.g. is it not using the car for small journeys; going vegetarian; not flying.
I appreciate that we should probably do all of the above, but which one thing would have the biggest impact?
A. Duncan: It depends on the individual. If you currently fly quite a lot (i.e. a couple of times a year), then cutting down or stopping flying will generally be the single most effective thing you can do to cut your carbon footprint.
The benefit of going veggie depends on what you replace the meat with – it's if cheese or air-frieghted veg then it won't help much, if at all. If it's seasonal produce then it will.
On driving, people often mention cutting out short journeys, and it does make sense to do so. But in truth it's generally much more effective (and often less of a pain) to focus your attention on longer journeys instead.
Q. POFAKKEDDthechair: I'm quite keen on the lighter later idea, where the clocks go forward in the spring and back in the autumn, but if I recall correctly, quite a few Mumsnetters were opposed to it - particularly those who lived in Scotland. What's your view?
A. Duncan: I'm all for advancing the clocks, as the evidence shows clearly that the majority of people would get more daylight overall (including in Scotland) and society would benefit in numerous ways. However, I'm not a morning person and I completely understand why some people are less keen.
The only thing I feel really strongly about is opinion and facts are kept separate in the debate. For example, it's sometimes said that advancing the clocks would make it more dangerous for children to go to school. But all the experts – including the Royal Society for the Prevention of Accidents – have stated emphatically that the roads would be safer if we advanced the clocks, including for children who tend to make longer and more complex journeys in the afternoons than they do in the mornings.
Q. Rob1n: What's wrong with carbon anyway? We are call made of carbon. We eat carbon. We couldn't live without carbon. Carbon dioxide is not the biggest greenhouse gas, water vapour is but we're not bothered about that? The concentration of carbon dioxide in the atmosphere has been much higher in the past, way before humans were on the scene, we didn't influence it then so what makes us think we can influence it now?
A. Duncan: Yes, we are indeed made of carbon! So are diamonds and tress and animals. And, yes, we couldn't live without any CO2 in the air (it would be freezing!) But none of that changes the facts.
- It's basic 100-year-old physics that if you add CO2 to the air, then it gets warmer. There is nothing in the scientific literature that challenges this.
- It's a simple observable fact that we add billion of tonnes of CO2 to the air, made of carbon that was previous locked up in underground oil and coal and gas reserves. There is nothing in the scientific literature that challenges this.
- We have reliable measurement of the amount of CO2 rising in the air and it rises in sync with the growing use of fossil fuels in the past century or two. There is nothing in the scientific literature that challenges this, either.
- Your point about water vapour isn't really relevant. Yes, water vapour constitutes the largest component of the greenhouse effect. But that doesn't affect the sensitivity of the climate to rising CO2 levels. Also, it's worth noting that by adding CO2 to the air, and warming the planet, we are indirectly increasing the amount of water vapour going into the air, and with it speeding up the greenhouse effect even further.
Q. Domesticslattern: Through my work, I have a couple of times met "green" experts, who often appear in magazines or on TV, telling us all about green issues. It seems to be such an industry nowadays. I once had the pleasure of going to one of their massive houses, which had recently featured in a Home and Gardens stylee photoshoot admiring its upcycled furniture and organic vegetable garden. I couldn't help noticing that he left the lights on upstairs when we were all downstairs; had an aga on all the time, and a dinner-plate style shower head; and takes domestic flights around the country in order to deliver talks on green living, as well as going on long-haul flights on occasion but "less than he used to". (He was a bit about this but explained that he offsets the emissions ). Dish the dirt Duncan. Are they all like this?
A. Duncan: Ha! There are certainly a few of those types around, for whom “green” means tacking a superficial aesthetic layer onto a completely rapacious consumer lifestyle. As you say, it's ridiculous to bang on about upcycled furniture while consuming endless amounts of fossil fuel in your home and travel.
However, in my experience the people who actually know what they are talking about – e.g. the various authors writing about carbon footprints – do quite a lot in their own lives to keep their emissions down. But they are of course less visible as there are no glamorous photoshoots in their houses.
Q. Paisleyleaf: I care about the environment, I really do. I keep our carbon footprint pretty low, installed a woodburner, car share, run an allotment, everything. But even I get put off and frustrated by all the greenwashing - it leaves you disheartened and confused about pretty much all of it, from buying a product to your fortnightly recycling collection. I think it makes people understandably cynical. I'd like to ask how we can know when we are on the right track with something and see through misleading information (even when it's perhaps sometimes meant genuinely enough).
A. Duncan: Easy answer: read The Rough Guide to Green Living.
Last updated: 5 days ago