To maintain a clean environment long-term, the ______ of resources must become apriority for current economies.

The economic savings generated from energy conservation can be achieved by improving the efficiency of ______.

The term 'sustainable development' as defined by the WCED suggests that development must be __________.

The crisis approach to environmental issues suggests that ______ must occur before significant changes are made.

In the second half of the 20th century, research has focused on environmental concerns such as air pollution and ______.

The primary factor driving the change in lifestyles in high-income and developing countries is _______. 

The economic savings generated from energy conservation are primarily achieved through ______ of machines and appliances.

The consumption of energy resources leads to the ______ of nonrenewable fossil fuels.

The term used to describe sustainable development according to the World Commission on Environment and Development is _______.

The impact of unplanned land use on the environment is _______.