Ozone layer bromine (Br). While there are natural sources for all of these species, the concentrations of chlorine and bromine increased markedly in recent decades because of the release of large quantities of man-made organohalogen compounds, especially chlorofluorocarbons (CFCs) and bromofluorocarbons. These highly stable compounds are capable of surviving the rise to the stratosphere, where Cl and Br radicals are liberated by the action of ultraviolet light. Each radical is then free to initiate and catalyze a chain reaction capable of breaking down over 100,000 ozone molecules. By 2009, nitrous oxide was the largest ozone-depleting substance (ODS) emitted through human activities. The
The Layer Monument The Layer Monument The Layer monument is an early 17th-century polychrome marble mural monument (320 × 350 cm) erected to the memory of the lawyer Christopher Layer (1531–1600), and located in the Church of Saint John the Baptist, Maddermarket, Norwich. Its inscription is in Latin, and reads in translation: The monument is notable on two accounts, firstly, its four figurines housed in its two columns, "Pax" and "Gloria", "Vanitas" and "Labor", are relatively rare examples of Northern Mannerist sculpture extant in Britain; secondly, these four figurines exemplify how, during the era of Elizabeth I, Christian iconography occasionally integrated symbolism which