Check About This Mac. From the Apple ( ) menu in the corner of your screen, choose About This Mac. The version of your operating system appears beneath âmacOSâ or âOS Xâ in the window that opens. If you need to know the build, click the version. This example shows macOS High Sierra version 10.13, build 17A365:
Biomass is fuel that is developed from organic materials, a renewable and sustainable source of energy used to create electricity or other forms of power. Some examples of materials that make up biomass fuels are: 1  scrap lumber; 2  forest debris;
The primary anthropogenic sources are combustion of fossil fuel, and the decomposition of organic materials associated with wetlands, rice paddies, and livestock manure. Nitrous oxide also occurs in low concentrations relative to carbon dioxide, but it is 230 times more efficient as a greenhouse gas. These factors combine to make it a 6% contributor to total the greenhouse effect. The primary anthropogenic sources are fossil fuel combustion, fertilizers, and deforestation. The only major greenhouse gases that are not naturally occurring are the chlorofluorocarbons. They come solely from anthropogenic sources such as the production and/or use of foams, aerosols, refrigerants, and solvents. They are present at an extremely low concentration in the atmosphere, however they are 15,000 times more efficient as a greenhouse gas relative to carbon dioxide.