Straw is generally a waste product and is mostly burnt by farmers, causing carbon dioxide production and hence an increase in greenhouse gases. These gases are responsible for heating up the planet’s atmosphere.
Straw burning causes air pollution through smoke and particulate emission. For example:
• Every 1 million tons of straw burned releases
56 000 tons of carbon dioxide.
• In the USA 200 million tons of waste straw are produced every year.
• Annual straw burning in California alone produces more carbon dioxide and particulate than all the electric power generating plants in the state combined.
This air pollution has prompted the California’s Air Resources Board to initiate the process of prohibiting this burning.
|Annual Carbon Dioxide Production from Power Plants and Straw Burning (in Tons)|
|California (only)||Tons Burned||CO2 (tons)|
|Rice straw||1 000 000||56 000|
|Wheat straw||97 000||5 000|
|Power plants||25 000||–|
|–California Agricultural Magazine, Vol. 45 #4 (July/Aug 1991)|
It is estimated that during one year in New South Wales alone rice farmers burn over 600 000 tonnes of rice straw, releasing 30 000 tonnes of carbon dioxide and 2 000 tonnes of particulate directly in to the atmosphere.
Clearly the potential is enormous
• Using strawbales for building could be useful in the effort to control global warming and atmospheric deterioration.
• Removal of straw from the rice fields would substantially reduce methane emission from microbial decomposition.
• Building with straw could significantly reduce the demand for native timber in houses so prevalent in the timber-consuming construction methods of today.
• Strawbale building eradicates the need to use paints and solvents that adversely affect the atmosphere and human health.