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Air Quality and the Promise of Biochar

Much has been made recently of the serious effects of much higher air pollution blanketing large parts of the world, especially in developing countries. In Northern Thailand, where many of ETHEQ's products originate, haze pollution has been growing every year over the last decade and has become particularly acute in the last two years. During 2019 and now in 2020, Chiang Mai, the largest city in the region, has been a regular in the top ten most polluted cities in the world during its dry and hot season that lasts from February to April. A city more known for its charming temples, beautiful nature and friendly people even topped the list as the most polluted city in the world on several unhappy recent occasions. There is evidence that long term exposure to the hazardous particulate matter found in the smoky haze can cause increased rates of respiratory illnesses, lung cancer and more. With pictures of the grey haze spreading in the news and on traveller websites, It has also been damaging to the local economy which depends heavily on tourism for jobs.

While the causes of this annual blanketing of smoke in the region are many, the clearing of land to grow non-traditional crops is a significant culprit. To make way for sugar cane and corn, in areas where before rice was predominantly grown, any brush found on fallow ground is cut and gathered and burned in open fires. In a city like Chiang Mai surrounded by mountains and receiving very little rainfall during the dry season, the result is a build up of small particulate matter in the air that eventually reaches extremely unhealthy levels. In regards to the climate change, burning of crops releases CO2 into the atmosphere as well as other greenhouse gases such as methane and NOx which contribute significantly more to global warming than CO2.

Our organic coffee growers are located in the mountains outside of Chiang Mai and utilize an age-old technology newly re-adopted that can help eliminate excess plant material without the smoke pollution and provides other environmental benefits as well. The solution they use is biochar, which is created by essentially heating biomass in low oxygen environments instead of burning it. The end-product of the process is a black solid coal-like substance ("biochar") that solves a number of issues simultaneously. Plant matter is not converted into the air pollution we see today, up to 50% of the carbon of the matter is sequestered into this solid instead of being released as CO2 and, finally, the biochar can be spread on the farmland to improve the structure and nutrient-retention capability of the soil.

The process to make biochar is not difficult. It can be done simply with a hole dug in the ground or an old oil drum or a trough. Within these structures, the biomass is then heated while also being deprived of oxygen in a process known as pyrolysis. Pre-Columbian Amazonians produced biochar from agricultural by-products by smoldering the waste in trenches. There are organisations in Northern Thailand (such as Warm Heart) that are working with local farmers to train them on how biochar can make their soil healthier and more productive and how to go about making their own kilns. With its increasing spread (pardon the pun) through croplands throughout the world we can all perhaps breathe a bit easier.

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