Provenance on the object, or an account of it in written materials from the same era, an object of study in archaeology or cultural anthropology may have an early provenance – a known history that predates modern research – then a provenience from its modern finding, and finally a continued provenance relating to its handling and storage or display after the modern acquisition. Evidence of provenance in the more general sense can be of importance in archaeology. Fakes are not unknown, and finds are sometimes removed from the context in which they were found without documentation, reducing their value to science.
Issues relating to biofuels ecosystems including rainforest in South America. In forest ecosystems, these effects themselves will undermine the climate benefits of alternative fuels, in addition to representing a major threat to global biodiversity. Although biofuels are generally considered to improve net carbon output, biodiesel and other fuels do produce local air pollution, including nitrogen oxides, the principal cause of smog. Issues relating to biofuels There are various social, economic, environmental and technical issues with biofuel production and use, which have been discussed in the popular media and scientific journals. These include: the effect of moderating oil prices, the "food vs fuel" debate, poverty