Solid Biomass and Climate Change
Overview
The term biogas refers to all the organic matter, produced by photosynthesis that exists on the earth’s surface. The source of all energy in biomass is the sun, with the biomass acting as a kind of energy store.[1]. The commonly used solid biomass in developing countries are firewood, animal dung and crop waste.
Indoor Air Pollution
About 3 billion people burn solid biomass on open fires and simple cookstoves, for cooking and heating purposes.Burning biomass on fires or rudimentary cookstoves releases pollutants such as carbon dioxide , black soot and other green house gases (such as methane). These pollutants contribute to indoor air pollution, which is one of the major casue of death in SouthEast Asia. In additon, more than 4 million people die prematurely, every year, due to illiness caused by indoor air pollution.[2]
Black carbon, which results from incomplete combustion, is estimated to contribute the equivalent of 25 to 50 percent of CO2 warming globally. Methane emissions are the second largest cause of climate change after carbon dioxide. It is clear that inefficient household energy use has adverse consequences for the environment, air quality and human health.[3]
For more information about indoor air pollution , see the article on Indoor Air Pollution (IAP) and Indoor Air Pollution (IAP) Measurement
Solid Biomass and Climate Change
Buring firewood results in deforestation which will further lead to natural calamities such as mudslide, landslide, flooding and soil weakening.However, no mass clearing of land for fuelwood has been observed in developing countries. Most of the fuelwood is collected from the local forest or roadside areas so, local forest depletion is more likely to happen in a developing country.[4]
Using agricultural residure or animal dung as fuel, instead of leaving them in the agricultural land could reduce the fertiliy of the soil and increase the chances of soil erosion.
Buring solid biomass is inefficient at converting heat to energy. Therefore, to attain an equal energy output, large quantities of solid biomass is required as compared to other energy sources such as biogas or LPG. This could accelerate the deforestation rate.
Carbon Debt
The extraction, transportation and combustion of biomass releases a significant amount of carbon into the atmosphere. This carbon is added to the atmosphere and it takes time before it is balanced by the ecosystem. According to a report by IPCC on renewable energy sources and climate change mitigation (2011), it can take decades, even centuries, before ecosystems; in particular forests can recapture the carbon that has been released during biomass combustion . This creates a "carbon debt" in the atmosphere.[5]
Therefore, it is necessary to concentrate our efforts on sustainable biomass use.This can be achieved either through transformation of biomass into less polluting forms or through improved stoves and better ventilation.[4]
