<span>loss of habitats
buildup of oxygen in the atmosphere</span>
The fall of Ancient Rome started from about AD 190. The Roman Empire was attacked by tribes such as the Goths and the Vandals. Civil wars in parts of the empire further weakened the rule of Rome and respect for Roman law dwindled as a result.
One-nation conservatism, it's a political viewpoint that defends the preservation of the established institutions and principles while advocating for the creation of social and economic programs (Keynesian, for example) to benefit the common people. The idea of the government intervention in businesses and the creation of new social programs in order to achieve changes in society is an group of economic theories called Keynesian economics.