In the United States, we long ago made a transition to an economy that met our heating and cooking needs by burning coal, natural gas, and oil, with a little hydropower thrown in to boot. In the first part of this series, I argue that after an oil peak, pressure will increase to cut trees to serve as fuel for heating and cooking fires, as well as to clear land for agriculture. Many other countries who have faced this pressure have become bleak places prone to soil erosion, mudslides, dust storms and finally, desertification.
To find sustainable solutions, we need to identify ways to use renewable resources at a rate which is slower than the resource can regenerate; as well as to use the resources in a way which does not produce more pollution than Nature and human health can safely absorb.
Part of a solution will probably be renewable sources of power, such as hydropower, solar, and wind – if they can be financed. But these renewables have important constraints, and take time, energy, and money to build, and I’m not going to address these technologies in this post. Instead, this post will focus on smaller scale, more distributed tools and techniques. I don’t claim to be an expert on any of the ideas in this post, and I hope that people who are can contribute to the discussion in this context.
To effectively reduce both of the main problems resulting from extensive use of wood (deforestation and particulate pollution), we should address both the demand and supply for wood fuel. On the demand side we can focus on:
- Reducing the need for heating fuel
- Using non-fuel heating and cooking technologies
- Using the most efficient ways of wood-based heating and cooking
1. Reducing need for heating energy
We can use many techniques to reduce the need to burn wood for heating. To reduce the need for heating, for example, we could consider:
- Consolidating families from many to one house
- Maximizing use of solar gain from windows during the day and covering them at night
- Wearing layers of warm clothes
- Using multiple blankets and comforters
- Sleeping/congregating in one room/bed to maximize body heat
- Hot water bottles
- Blocking off parts of the house which don’t need to be heated
- Earth-sheltered homes or basements (although this would be difficult to retrofit to an existing home)
2. Solar Technologies
Solar technologies which don’t burn fuel should be used whenever possible. I’m not talking about expensive photovoltaic systems, but technologies which directly turn the sun’s energy into heat for cooking and heating. These would include solar ovens and cookers, passive solar heating, solar water heaters, solar heaters, and solar food dryers. Of course, the great advantage of these technologies is that they don’t require any ongoing wood or fuel usage, and also produce no pollution. Therefore there are minimal, if any, negative health effects, no ongoing cost to operate, and no need to gather fuel.
The use of these technologies, which don’t require the careful manufacture and rare materials that photovoltaic systems do, could go a long way toward reducing the pressure on our forests and urban trees. Some of these solar tools can even be improvised from scavenged materials and built ultra-locally.
In some of the sunniest climates, the use of these solar technologies could drastically reduce the need to use wood. For example, Sun Ovens International reports that the use of Sun Ovens can cut the need for cooking fuel by up to 70%. After personally using a Global Sun Oven since spring of this year, I believe I could use it to cook lunch and dinner on every sunny day between mid-April and mid-October, here in Oklahoma City. Of course, solar tools are more useful in sunnier regions, and often cannot be used very effectively on cloudy days.
3. Efficient heating and cooking
Fireplaces and open fires waste most of their heat and generate quite a bit of pollution. In fact, fireplaces might not properly be called a "heat source" since they suck warm air up the chimney. More efficient ways to use wood for heating and cooking might include Earth ovens, Masonry/Finnish heaters, Kelly Kettles, super-efficient EPA-certified wood stoves, and hay box cookers. Pellet stoves could be part of a solution, but they require a dependable source of the wood or corn pellets, and also require electricity to operate, so would require some kind of PV system or other on-site power generation.
Masonry, aka Finnish heaters, have a reported 90% combustion efficiency, compared to 10% efficiency for a standard fireplace or 60% for an average woodstove.
The mass of a brick or Earth oven retains the heat so that it can be used to cook multiple dishes throughout the day. A hay or box cooker insulates a pot which has been brought to boiling, so it can continue to cook without any additional fuel. A Kelly Kettle (aka Storm Kettle) can reportedly heat 2 pints of water for tea, coffee, broth, or water pasteurization with only a few twigs in 4 or 5 minutes. Even a simple mbaula (clay cook oven), if compared to an open cook-fire, can reduce the amount of wood burned by two-thirds.
An efficient, EPA-certified wood stove can heat water, cook food, and heat a house – all at once. Still, any kind of wood burning will generate particulate pollution, and the use of wood-burning stoves by hundreds of thousands of households within a city could spell disaster. While many people will not have a real choice, burning wood should be minimized in favor of solar technologies whenever possible.
Kelly / Storm Kettle
Efficiency is not only about technology, but also technique. Efficiency could mean a small business owner using an Earth oven to bake bread for the neighbors, instead of each household needing their own Earth oven. Or an efficient stove and a series of box cookers in one location per block – the stove could be used to bring the cookers to boil, one after the other, and then set in the box cookers. These techniques, which rely on community teamwork and cooperation, could also drastically cut fuel use.
Supply side (providing fuel) techniques and strategies don’t prevent particulate pollution, but they can help reduce deforestation and the resulting ecological damage. On the supply side, we should consider these strategies:
- Sustainable Harvesting
- Alternative fuel crops
1. Sustainable Harvesting Techniques
To be sustainable, we cannot harvest wood any faster than it can regrow. The wood should also be harvested in a way to prevent destruction of ecosystems, soil erosion, and other results of methods such as clearcutting. This will have to be tailored to each forest, to each type of tree, and will therefore vary from region to region.
So first, let’s use all the resources that are freely available. Limbs, twigs, and trees that have already fallen in urban areas should be USED as much as possible, instead of burned in open landfills or turned into landscaping mulch. Currently, municipal governments spend vast amounts of energy, labor and money hauling off unwanted "waste" wood from individual properties. How much better would it be if this resource could be used near the source, or redistributed locally?
Secondly, many trees and shrubs benefit from regular pruning, and re-grow their limbs within several years. Tree and shrub pruning, instead of tree harvesting, could be a way to provide firewood.
Coppicing is a method of forest management in which the same deciduous trees are harvested repeatedly. Because the root mass of the tree is preserved when the tree is cut, the tree will grow multiple sprouts that can shoot up to 4-15 feet in a year. Coppiced forests are usually managed by rotating through different sections, which leaves the trees in the other areas to grow and host various plants and animals. Coppicing actually prolongs the life of a tree. A properly coppiced tree may not die for centuries, during which time it will be harvested dozens of times. Therefore coppicing, combined with continuous tree planting to account for trees that die, is a virtually sustainable method of providing wood for heating and cooking.
Selective harvesting is a method of cutting selected single or groups of trees within a forest, to avoid the disruptive ecological effects of cutting down a wide swath of trees. It can be combined with coppicing to preserve a more natural forest setting.
Reforesting our cities and forests will serve several purposes. We can plant urban food forests filled with fruit and nut trees, which could provide local food security. Replanting trees can help remove carbon dioxide from the atmosphere and provide shade and cooling in hot weather. Replanting will replace trees that have been harvested for fuel, and these trees, after several years, can then be pruned to provide wood fuel. On an economic level, reforestation would be an excellent "green" collar job.
3. Alternative fuel crops
After my first post, several people suggested alternatives to harvesting traditional forest trees. One, the Tree of Heaven, is an invasive species that grows like a weed, because it is. It’s already present in 42 states, and would be a good candidate for coppicing (apparently it regrows very vigorously, and suckers). The problem is that invasive plants are a scourge, but in locations where this tree already exists, it might prove to be useful.
The second is hemp. For those that don’t know, hemp is not marijuana, because the strain grown for fiber/fuel/etc. contains only .3% of the psychoactive THC, not enough for any kind of intoxicating effect. Hemp produces a lot of biomass, is extremely easy to grow, and has multiple (some claim infinite 🙂 uses, including biodiesel. Frankly, I don’t know much about the use of hemp for fuel. Any contributors out there who do?
Sounding the alarm
Using a wood stove can be a great strategy to prepare for peak oil, on an individual basis. When used on a mass scale, especially in urban areas, it could be devastating – to our health, to the health of our ecosystems, and to the climate.
Humans have needed energy to meet their cooking and heating needs for thousands of years, and that won’t change any time soon, regardless of the availability or cost of electricity, natural gas, or heating oil. A few cold winters, combined with a poorer population and electrical blackouts, could result in a dramatic cut in our urban tree population or our forests.
So how do we meet our needs, while caring for the health of the planet and our neighbors?
A combination of the above mentioned technologies and techniques, if deployed promptly and properly, could address the deforestation and pollution issues, while also decreasing our use of fossil fuels – TODAY.
Ideally, we need to minimize our need to heat through insulation, weatherizing and clothing/blankets. Over time, our bodies would acclimate to lower temperatures. We would use solar technologies to heat our homes and cook our food on every sunny day. And for the remaining amount of wood-burning we might need to do, we would use sustainably harvested wood (pruned or coppiced) in the most efficient wood-burning technology possible.
But how do we get these ideas out to the public? How do we persuade citizens, governments, and communities to adopt these technologies and techniques? How could we push this information out to the public in an emergency or disaster?
More on this to come in Part III.