The Lawn

The ubiquitous lawn is something so familiar and so common, that we rarely think about it, beyond the need for its regular maintenance. Yet lawns are very wasteful, environmentally damaging, and a strong source of carbon emissions. If we are to move towards a more sustainable future, we need to re-examine the lawn and look for alternatives.

Originally, the natural lawn was just an area of grassland that was regularly grazed by sheep, cows, or other livestock, in other words, pasture. The idea of suburban homes, surrounded by large artificially maintained lawns, didn't begin until the end of the 19th century in the United States. Cities at that time were dirty, polluted and rife with disease. A home in the suburbs was intended to recreate the idea of a "country home" where those who worked in the city could escape to. After World War II, with the rise of the automobile, this idea exploded and the suburban lifestyle we take for granted today really took off.

Unlike natural lawns, of course, the typical suburban lawn must be maintained. We generally don't keep livestock anymore, so we obviously cannot rely on grazing. This means the lawn must be regularly mowed, often using fossil fuel energy. To prevent weeds, pesticides are needed, and in many areas fertilizer (made from fossil fuels) and watering are needed, as the soil is not being naturally built up, and there is insufficient ambient rainfall.

A pasture could be maintained solely through natural processes, such as regular rainfall, the grazing of livestock, and the natural fertilizer provided as waste products from that livestock and other local animals. Soil would be naturally built up, and the pasture would also be a source of food and other resources. Cows provide milk, sheep provide wool, and livestock of all types provide food. No energy input, other than the sun, is required. Carbon is absorbed by the soil and the plants.

Artificial lawns, however, are a net source of carbon. As a recent study concluded, when the cost of maintenance is included, the typical lawn generates four times more carbon than it stores. This makes sense when you consider the carbon released by gas or electric mowers, the use of fossil fuel based fertilizer and the degrading of the soil. Nitrous oxide is also released from the soil because of fertilization, which is a greenhouse gas 300 times more powerful than carbon dioxide.

It's even worse, though, as the study doesn't appear to take into account the emissions involved in manufacturing millions of lawn mowers, leaf blowers, sprinklers, trimmers, and other tools, or their transportation, storage, and sale. Also, in much of the world, grasses could not grow without regular watering. In some areas, this water must be diverted from far away, involving the construction of large dams, pipelines, waterways and other infrastructure. Clearly, the amount of energy required to build and maintain such infrastructure is significant.

Outside of the energy cost, however, the diversion of water on such a large scale has many other environmental impacts. Entire streams and rivers have dried up in many areas, leading to the collapse of local ecosystems. Many animals have been forced to flee, and those that could not move or adapt have simply gone extinct. For plants and fish, this has been even worse, leading to more extinction and a great loss of biodiversity.

Another problem is simply the loss of land. A dense residential community takes up several times less space than the typical suburban sprawl. Much of the land paved over and converted into lawns was originally farmland, or just natural forest, grassland, wetland or savannah. The natural landscape lost can no longer provide a home to animals, or absorb carbon from the atmosphere. Large houses, widely spaced, require more materials and energy to construct, and they require a larger, more energy-intensive infrastructure.

There are many alternatives to lawns. We can simply build more densely, without space for lawns, yet include natural parks and other green areas throughout a community. In Europe some common areas like these are still used for grazing today. Some of the space could also be used for community gardens, or other projects to grow more food locally. Others could simply be left in a natural state, leading to the return of animals and a variety of plant species. In existing neighbourhoods, lawns can be replaced with gardens, switched to other plants that require less or no maintenance, converted into permaculture, or simply allowed to take their natural shape.

The threat of global warming, and other environmental damage, is only increasing. There is a recognition that we need to move towards a sustainable way of life, yet very little is being done outside of the narrow scope of encouraging better consumer choices and minor lifestyle changes. Even simple and obvious steps, with little impact on the majority of people, are being ignored. We need to also examine those things we take for granted, like lawns, and ask if they can ever be sustainable. If the answer is no, then what exactly are we doing?