Coal the heat and pressure of deep burial causes the loss of water, methane and carbon dioxide and an increase in the proportion of carbon. Thus first lignite (also called "brown coal"), then sub-bituminous coal, bituminous coal, and lastly anthracite (also called "hard coal" or "black coal") may be formed. The wide, shallow seas of the Carboniferous Period provided ideal conditions for coal formation, although coal is known from most geological periods. The exception is the coal gap in the Permian–Triassic extinction event, where coal is rare. Coal is known from Precambrian strata, which predate land plants—this coal is presumed to
The Carbon Principles The Carbon Principles The Carbon Principles are a series of guidelines established by three leading Wall Street banks — Citigroup Inc., JP Morgan Chase, and Morgan Stanley — to assess the risks in financing electric power projects in terms of climate change. These principles call for "enhanced diligence" in evaluating electric power industry borrowers in terms of their use of energy efficiency; renewable and low-carbon distributed energy technologies; and conventional and advanced generating technologies. These guidelines were announced in February 2008 to address the increasing public concern over the plans to create over one hundred coal power plants in the