Farming is essential to human life, but it also has significant environmental impacts, including consuming over 70% of the world’s freshwater supply, linked to phosphate pollution in rivers and the production of greenhouse gases. In this series, we will look at the different challenges across the industry. In the first issue, we will cover stubble burning.
Stubble Burning and Greenhouse Gases
Stubble burning, the practice of setting fire to the leftover stalks of crops after harvest, is a harmful practice to the environment. When the crop is burnt, it releases large amounts of carbon and other harmful pollutants into the air, including carbon dioxide, methane, and nitrous oxide, into the atmosphere; these gases are major contributors to climate change and air pollution. Stubble burning also releases particulate matter, which can have negative respiratory and cardiovascular effects on people living in nearby areas.
Burning the stubble also contributes to the loss of nutrients in the soil and can lead to soil erosion.The practice of stubble burning also contributes to deforestation as it destroys the natural habitat of wildlife and disrupts the delicate balance of ecosystems.
Legal or Illegal?
Despite the damage it causes, stubble burning continues around the world, both legally and illegally.
Stubble burning was banned in the UK and EU in 1993. In China, stubble burning has been banned, as it has in Thailand, but it still occurs. Even in countries where it is conducted legally, it may be conducted against the ESG policies of crop buyers.
Given the scale of these countries and the remote nature of farms – enforcement is challenging for governments and almost impossible for companies. The further down the supply chain a buyer is, the more unfeasible it may seem to verify a farming practice. How is Pepsi going to verify the stubble-burning practices of the 100,000 sugar farmers in Thailand who supply the company, who supply the sugar factory, who sell to the trader, and who provides the sugar to Pepsi?
Remote Sensing May Provide an Answer
While monitoring stubble burning through traditional methods may be impossible – it can be done via remote sensing. Satellite data can be used to detect stubble or pre-harvest burning and take action accordingly.
The burning of a crop, e.g. pre-harvest burning of sugarcane in Thailand, will often happen at night. While most satellites are not collecting data at this night (to conserve power) the burn signature can still be detected. . Smoke trails, from the smouldering fields, can be identified, and the location of the stubble burning can be detected.