Biomass energy differs from other renewables, however, in the extent to which its use is directly tied to the farms, forests, and other ecosystems from which biomass feedstocks are obtained.
Biomass can be used to produce renewable electricity, thermal energy, or transportation fuels (biofuels). Biomass is defined as living or recently dead organisms. Ethanol, today's largest volume biofuel, is produced through a biochemical conversion process. In this process, yeasts ferment sugar from starch and sugar.
Because of this close association, the use of biomass has the potential to result in a wide range of environmental and social impacts, both positive and negative, above and beyond its use as a substitute for fossil fuels. Impacts on soils, water resources, biodiversity, ecosystem function, and local communities will differ depending on what choices are made regarding what types of biomass are used, as well as where and how they are produced.
This is why biomass needs to be produced and harvested as sustainably as possible.
In this sense, sustainability refers to choosing management practices that minimize adverse impacts and complement local land-management objectives, such as farm preservation, forest stewardship, food production, and wildlife management. Many traditional food crops, such as corn, sugar and vegetable oils, are also some of the most commonly used energy feedstocks. Furthermore, agricultural land may be shifted from producing food to the production of dedicated energy crops.
The use of agricultural crops and lands has undoubtedly contributed in part to increased prices for many of these commodities. Many other factors, however, have contributed much more substantially to this increase, including inflation of the dollar and especially the rapid rise in price of fossil fuels.
Oil and natural gas, in the form of fuel and synthetic fertilizers, are two of the biggest economic inputs in food production and distribution. There are many opportunities to further reduce the conflict between food and fuel production, including an increased use of agricultural wastes, logging residues, food scraps, municipal solid waste, and marginal lands. Another issue heavily associated with biomass production is greenhouse gas emissions from land management and land use change.
These refer to emissions of greenhouse gases especially CO2, CH4, and N2O resulting from agricultural inputs, management practices, and land use changes associated with production of biomass. These emissions can be divided into direct and indirect sources. Direct emissions refer to those resulting from land clearing, agricultural inputs such as fertilizers , or management practices undertaken in the process of growing or harvesting a biomass crop. Indirect emissions are associated with market-driven land use change.
These are the emissions that occur when forests, grasslands, or other ecosystems are cleared to produce crops or other commodities to compensate for land that has been diverted to energy production. The effects are difficult to quantify or attribute, making indirect emissions from land use change ILUC a very controversial subject.
Finally, it is important to remember that biomass markets will add value to biomass products, residues, and productive lands. This value will help improve the economic viability of working lands and act as a positive incentive to help preserve farms and forests from the accelerating threat of urban and suburban sprawl — the greatest land use impact. From where to buy compostable bags to how much money your neighbor saved on their home improvement project.
Biomass and Biofuels are all domestically produced renewable energy sources that can be used as a sustainable feedstock for the production of transportation fuels, heat and power. A dynamic city like San Francisco requires the efficient use of clean, renewable energy to meet the needs of today and future generations. Our innovative policies and programs help San Franciscans use energy wisely, while saving money and reducing environmental impacts.
SF Environment aims to reduce travel-created carbon by getting people out of cars and instead traveling by walking, biking or public transit.
go We also are greening the City fleet of vehicles and encourage the public to reduce their impact by supporting cleaner fuels and vehicles. Imagine a world in which nothing goes to landfills or to incinerators.
As the first city to adopt the Precautionary Principle, San Francisco strives to protect the health of its residents, visitors and the local environment. SF Environment develops programs and policies to help individuals and businesses make safer choices in products, practices and services.
San Francisco is habitat for , people — meeting needs for space to work, play, and learn; for food, water, and air; for community with local flora and fauna. SF Environment provides support for urban agriculture and forestry and green buildings, helping residents and businesses harness environmental opportunities. Reducing carbon emissions is central to ensuring a sustainable future for San Francisco.
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