Image source: Taiga Company.

1) If you buy just one new appliance in 2010, make it a really efficient fridge-freezer. The improvements in the energy use of the best fridge-freezers have been really impressive in the last few years. If you have an old refrigerator, it may be responsible for as much as a sixth of your electricity bill. A good new machine might use less than a half as much power, particularly if it is not too large. A second benefit is that by choosing to buy a really efficient refrigerator you will be sending a clear signal to the manufacturers that energy consumption matters. An impressive new web site – www.energytariff.co.uk – allows you to compare the electricity used by almost all the appliances currently in UK shops. You can make well-informed choices from your computer.

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2) Buy fewer, better clothes that are easy to wash. The worldwide textile manufacturing industry is a major user of energy. Additionally, growing natural fibres such as cotton or wool creates substantial volumes of emissions. A light woollen sweater might be responsible for over 40 kilograms of emissions before it gets to the shop. Even a T-shirt can embody over 6 kilograms of CO2 and other greenhouse gases. The average Briton buys seven of these a year. Could you make do with buying fewer, and making sure that they last longer? Buy organic cotton and you also know that your garment hasn’t added to the serious problems of pesticide pollution in central Asia. Can you switch to man-made fibres for some of your clothing? These fabrics generally last longer and can be washed at low temperatures, using less energy.

3) Think about trading in your car for membership in a car-share club. If you are typical, you use your car for one hour a day but pay for all 24. A car sitting at the kerb has to be insured, financed and maintained even if you hardly use it. Commercially run ‘car clubs’ are growing fast in many cities. They offer rentals from as little as £3.95 an hour or cars can be hired by the week from locations within a few minutes’ walk of your home. Car clubs reduce the cost of motoring for many people and each rented vehicle takes several private cars off the road. If there are no clubs in your area, simply sharing a car with neighbours may be a good alternative.

4) Look at the costs and benefits of putting solar panels on your roof. In April next year the government is introducing a new scheme to persuade us to generate our own electricity from photovoltaic panels. For every unit of electricity produced, the householder will get paid over 36p, around three times the price we are currently paying the electricity company for the power that we use. Solar panels are also coming down in price, meaning that on south-facing roofs in southern Britain you can expect a financial return of about 7% a year on your investment. It isn’t riches, but it certainly beats the interest you can get in a bank. Equally important, families that generate their own electricity seem to become more conscious of their energy consumption and focus successfully on cutting all their utility bills.

5) Eat less beef. The intensive rearing of cattle is a major contributor to greenhouse gases. These animals produce methane in their digestive processes and slurry heaps also generate large amounts of this powerful global-warming gas. What’s more, cows on most farms are fed large amounts of maize and other feed during the winter months. Growing these grains took energy and considerable amounts of artificial fertilizers. And as more and more of the world’s population demands meat in their diets, the pressure to cut down forests to create open pasture land increases. Perhaps 20% of the average Western carbon footprint is created in the food production chain and reducing the amount of beef eaten is an important step you can take to reduce this figure.

6) Try the new energy-efficient lights – LEDs. Many homes have replaced all their larger bulbs with energy-efficiency fluorescent lights. But many homes still have tens of halogen bulbs in kitchens and bathrooms. They use a lot of power and regularly need replacing. A new technology – LED lighting – uses only tiny amounts of electricity and directly replaces the small halogen downlighters. It’s only really in the past year that LED lights have become realistic alternatives. Before, they tended to have an unattractive blue colour and not produce enough light. But after recent improvements, now is the time to try some in your kitchen. They’re not cheap, but they’ll save significant amounts of electricity and will last for decades.

7) Keep your electronic devices for longer. Some of Apple’s fancy new computers have footprints of about half a tonne of CO2. This may be substantially greater than the CO2 produced generating the electricity that the computer uses in its lifetime. This could also be true for your new phone or your laptop. Although no one argues that you should waste power by unnecessarily leaving your gadgets on, the main focus should be on keeping them for longer. Doubling the average lifetime of our PCs and mobile phones would have a much more important impact than always turning them off at the mains socket.

8) Get better central heating controls. We all know that houses should be better insulated and have more efficient boilers. But for some households it may be simpler and less expensive to improve the heating controls. Check that all the household radiators have thermostatic valves. Make sure that they are turned off in rarely used rooms. Should your central heating be programmed to turn off earlier in the evening? Can you install a new computerised thermostat, such as the Dataterm (www.warmworld.co.uk), which will intelligently work out when your heating needs to be on or off? Running your heating with more care can save at least as much as investing in a new boiler. It doesn’t necessarily require you to run your house at a lower and less comfortable temperature.

9) Use the train to get to your holiday. Why not catch a train to the Mediterranean rather than driving or flying? The trip from London to Marseille can take as little as six and a half hours and you get to see something of France on the way. Book in advance and the one-way price is only £62, no more than a typical air fare. It’s similar with train travel in the UK. Going to popular UK holiday destinations by rail will almost certainly save you time and money and you can usually hire a car at the resort when you need it. Not flying to your holiday destination will probably reduce your carbon footprint by at least as much as any of the other choices in this list.

10) Grow some of your own food. Enthusiastically cultivated, a standard urban allotment can provide all the vegetables for a family of four for half of the year. In our household, we’re still eating home-produced tomatoes and lettuces grown under cover. If these vegetables had been grown in a heated Dutch greenhouse using large amounts of artificial fertilizer, shipped in a refrigerated lorry to a huge warehouse and then sold from an open chiller cabinet in a supermarket to which we’d driven, the carbon cost would be a thousand times greater. The advantages of local food are sometimes exaggerated: the greenhouse gas cost of South African apples may be no greater than English fruit kept in a cold store for months. But the footprint of seasonal produce that you grow yourself is tiny, and may even help wean your family off processed food.

11) Support international agencies trying to decrease the worldwide growth of population. The world now has over 6.7bn people, probably rising to well over 9bn by 2050. Each additional person adds to the strain on the planet’s ecology. Mike Berners-Lee, a leading researcher on carbon footprints, says in his new book, How Bad Are Bananas?, that a baby born today will add almost 400 tonnes to the UK’s emissions over his or her lifetime, even if we reduce greenhouse gases as fast as the government intends over the next decades. Cutting population growth is a vital part of any global strategy for averting the worst effects of global warming. In countless places around the world it has been shown that improving women’s education and giving easy access to family planning helps reduce the number of children in each family. As well as reducing fossil fuel use and minimising forest loss, we must therefore help women in poorer countries manage their own fertility.



A shorter version of this article appeared in the Sunday Times on 29 November 2009.

Lord Stern says the meat industry damages the environment. Image source: VirtualTourist.com

Clearly irritated that his argument in an interview in the Times had been boiled down to a ‘go veggie to save the planet’ headline, Nicholas Stern has issued a clarifying statement:

I think that once people understand the great risks that climate change poses, they will naturally want to choose products and services that cause little or no emissions of greenhouse gases, which means ‘low-carbon consumption’. This will apply across the board, including electricity, heating, transport and food. A diet that relies heavily on meat production results in higher emissions than a typical vegetarian diet. Different individuals will make different choices. However, the debate about climate change should not be dumbed down to a single slogan, such as ‘give up meat to save the planet’.

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Without representing his position as advocacy for veganism, Stern’s point on food is correct: the average western diet makes a very substantial contribution to climate change. Rough calculations suggest that food production is responsible for between 15% and 20% of total UK greenhouse gas emissions. Food miles are important and the electricity consumption of a big supermarket might surprise you. But the really serious issue is the intensive farming of livestock, particularly cows and sheep, which generate as much as a half of the total emissions. One study from 2007 suggested that the CO2-equivalent emissions of global warming gases from beef production could be as much as 50 times the weight of the meat itself.

There are three elements to the problem: farmed livestock eat large quantities of grain, they belch methane and they use land that might otherwise be forest. To get a kilo of beef, the animal typically eats about eight kilos of grain. That corn or wheat took energy to grow, required a lot of artificial fertiliser and then needed to be processed into a cake for cattle. Some of the fertiliser applied to fields breaks down into nitrous oxide, a far more powerful global warming gas than carbon dioxide. Cows and sheep emit methane as bacteria in their digestive tracts digest the cellulose in plants. And, worldwide, the gradual increase in the consumption of meat creates pressure to cut down forests to create new pastureland and cropland for grains to help feed the livestock.

As countries get more prosperous, their populations tend to eat more meat. So unless we do something, the impacts of livestock farming are probably going to get worse. And, by the way, it isn’t just meat. The same arguments apply, albeit with less force, to dairy products as well. The best diet from a climate point of view is probably a mixture of dried plant-based foods, such as beans and nuts, with large quantities of locally grown seasonal vegetables and fruits. It may also be best for our health and it would certainly save us money. In fact, the simplest and cheapest way of largely meeting your commitment to the 10:10 campaign would probably be to eat vegan foods for half the week. To many people this will seem a less demanding challenge than not flying for a summer holiday.

Nevertheless, the reaction to Lord Stern’s statement has been unpleasantly vicious. People have seen his views as another illustration of how “climate change” will be used as an excuse for the elite to limit the choices of ordinary people. We are already being told to drive less, not to fly and to buy dim lightbulbs. Stern’s comments suggest a future campaign to reduce our hamburger consumption.

Unfortunately, the many stresses on the world’s ecosystems mean that either we eat less meat or change our farming and food manufacturing methods. The greenhouse gas emissions from agriculture, food manufacturing, transport and retailing are now about two tonnes a head, about as much as we can afford to emit from all our activities in 2050. Either we decide to eat a very different diet, as Stern suggests, or we try to change agriculture so that it becomes a helpful part of our drive to reduce emissions. Instead of depleting the soil and abusing animals in pursuit of cheap meat, we could put our weight behind schemes for using agricultural soils to sequester CO2. A new campaign, called Climate Friendly Food, may offer us a way of continuing to eat some meat and looking after the global atmosphere at the same time.



This article was originally published in the Guardian on Tuesday 27 October 2009.

Key Farmers Cameroon's coordinator, Etchi Daniel-Jones, at a plot in Ediki, in which the difference between char and non-char maize was exceptionally big. In this case, the plants on the control (left lower corner) were barely in their 8th leaf stage, whereas the plants on the char-plots (right, upper corner), were already tasseling. Photo credit: Laurens Rademakers, Etchi Daniel-Jones. Source: biocharfund.org.

Biochar Fund has reported extremely encouraging first results from its field trials in South West Cameroon. Working with small groups of subsistence farmers around the town of Kumba, the Fund set up and managed a large-scale experiment to assess whether maize (corn) yields were improved by the addition of biochar to the soil. The biochar was made from local agricultural wastes and tree thinnings. The data from the trials strongly suggests that biochar adds greatly to food production. Some areas showed yield improvements of more than 250% over the control plots. The areas dosed with biochar also showed substantially increased production of crop biomass, including roots, stalks, and leaves.

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Many field studies in the tropics carried out by academic researchers have shown that biochar improves soil productivity. (For more details on what biochar is and how it is made, see an earlier article on this site, here.) Biochar Fund’s research did more. It showed that poor farmers typically making less than $300 a year from their crops were able to improve their own yields using simple techniques both for making the char and adding it to the soil. Average production of maize from this area of Cameroon is about 1.7 tonnes per hectare compared to about 7 to 9 tonnes in the EU or US. If the initial results are replicated elsewhere, the impact of biochar could see yields increase by 40% above what would otherwise be obtained.

Biochar Fund research techniques
The experimental methods seem robust. A large number of small groups, comprising 10 to 30 members, were asked to participate. They cultivated 75 test areas across very different soil types, including weathered, degraded land as well as productive volcanic plots. Each area was asked to plant 12 sub-plots, 4 without biochar, 4 with biochar applied at 10 tonnes an acre, and 4 with 20 tonnes an acre. Each type of plot was then divided into areas without any fertiliser, with organic-only fertiliser, with artificial fertiliser, and with both types of fertiliser together. The fertiliser was applied at the rate usually used in the research area. (Because of a shortage of money, many areas would usually not have fertiliser applied.)

The biochar was made in a low-technology kiln using agricultural wastes from the previous harvest and some wood cut back from trees surrounding the cultivated areas.

The farmers sowed seed densely and harvested the corn when it was ready. They weighed the whole plant, including roots, the cobs, and also the grain itself. Some of the groups did not produce usable results because the grain was stolen (‘because it looked so good’ report the affected farmers) or because of pest damage or because of misunderstandings about how to apply the methodology. But 41 of the 75 test plots yielded data on biomass weight and slightly fewer on grain yield.

The results
The principal results from the experiment are as follows:

• a) Adding biochar at the rate of 10 or 20 tonnes a hectare typically added about 85% to the weight of grain produced compared to the adjacent plot with no fertiliser.
• b) This is about the same increase as would be gained by adding both organic and artificial fertiliser to the unfertilised soil. So biochar is as effective at increasing yields as heavy application of fertiliser.
• c) If both biochar and two types of fertiliser are added, the yield rises to an average of about 140% of the level without any additions. Biochar therefore substantially increases the food production of land above what would be achieved either with or without added fertiliser.
• d) It seems as though the most striking results are found on the poorer soils.

Full data analysis is here and in PDF form on the data page.

These results are preliminary but they show the powerful benefits that biochar might bring to food availability in many tropical soils. Getting heavy doses of char into the soil will be demanding but the great advantage of biochar may be that it only needs to be applied once and its effects persist for decades. The results from the second maize sowing of the year (to be harvested in the next few weeks) will show whether the yields improvements continue.

The implications of the research
The beneficial results from the application of biochar on degraded tropical soils are now too frequently reported to be a statistical artefact. Biochar works. The remaining opponents of biochar focus on the dangers of using native forests as the source for the combustible material. If biochar is so good at improving yields, they say, then forests will be cut down to improve soils. The Cameroon results show that this should not be the case. Here are some numbers from the experiment:

• Applied at 10 tonnes a hectare, biochar added about 4.5 tonnes a hectare to the total biomass, excluding the food grains, of unfertilised land.
• One tonne of organic matter will typically produce about one third weight of biochar – say 1.5 tonnes a hectare.
• So the weight of biochar added to the soil (10 tonnes/ha) will be repaid in increased biomass production (not just food) within about 6-7 years.
• Therefore, if one seventh of the land has biochar added for seven years the net biomass availability by the end of this period will be higher, prospectively for ever if biochar permanently increases yields.
• There should therefore be very limited pressure to cut down forests to make biochar – biochar can be made from the incremental biomass produced on the land to which it has been applied.
• This conclusion would be even stronger if we took into account the fact that some areas, such as parts of Cameroon, can produce two crops a year. Payback would be twice as quick.

The most important result from this remarkable experiment in Cameroon may be that it lays to rest the worry that biochar will exacerbate deforestation. In fact, by increasing biomass production biochar should reduce the need to cut down trees for fuel.

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The experiments in Cameroon will continue. Biochar Fund (www.biocharfund.org) is also running several other trials. Here is an excerpt from its recent email:

Given your continued interest in biochar research, we are glad to keep you up to date on our activities in the future. These activities include a large project in the Democratic Republic of Congo, which is aimed at reducing the deforestation rate resulting from slash-and-burn farming; a project that aims to build highly integrated agroforestry farms which protect biodiversity and ecosystem services; and the development of a novel cocoa drying technology which coproduces biochar.

If I may give a personal view, I think these research projects are among the most important in the world today. Please consider giving your support to Biochar Fund and Key Farmers Cameroon in whatever way you can.