Earth scientists have concluded that the methods of harnessing energy that have been used over the past two centuries, such as the burning of fossil fuels, are causing climates around the world to change more quickly and suddenly than ever before in human history. evidence includes increased temperatures in the air, rising sea levels, and the shrinking of ice glaciers at the north and south poles. the most complex level of organizational hierarchy that climate change could potentially affect is earth’s biosphere. communities. organisms. populations.

For review 1. in terms of which government is sovereign, differentiate among a unitary system, a confed- eral system, and a federal system of government. 2. to which level of government does the constitution distribute the enumerated po implied powers? concurrent powers? reserved powers? provide several power. 3. what matters fall within the scope of state sovereignty? differentiate among dual federalism, cooperative federalism, centralized federalism, and conflicted federalism. how does the national government use grants-in-aid, mandates, and preemption to direct the policy of state and local governments? 6. what do we mean by intergovernmental relations? why is the term a good description of u. s. federalism today? 7. list several advantages and several disadvantages of a federal system.